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Home > Resources > Glossary of Terms Resources Where to buy Tips and Techniques Image Gallery Trim & Mouldings Siding, Exterior Accessories & Shutters Fencing, Decking, Railing and Columns Pipe & Fittings Window & Door Profiles Document Library Terms and Conditions Warranty Information FAQ Glossary of Terms Videos Glossary of Terms Trim and Mouldings Terms Pipe and Fittings Terms Window & Door Terms Trim and Mouldings Terms: Cellular Vinyl and Polymer Mouldings Royal Mouldings has pioneered the marketing, promotion, and manufacturing of the Cellular process. This process uses specially formulated resins, such as PVC or Polystyrene allowing them to expand to a "full size" profile with a strong inner cell and outside surface that emulates the strength benefits of wood without the natural defects of wood. There are no surface blemishes and only minimal on-going maintenance. The products do not rot and are available in the Industry's largest selection of finishes. Cellular Vinyl An extruded PVC profile with a solid outer skin and strong durable cellular core. Clearwood®PS A patented ready to finish process designed to give a defect free surface for painting, staining and Faux finishing with the look of natural wood. Clearwood also can be painted with oil or latex paint. Readi Finish® A patented finish that does not require painting and is guaranteed for 10 years against UV discoloration. BASIC PROFILES AND USES (Courtesy Wood Moulding & Millwork Producers) Astragal This moulding includes two different types, a T-Astragal and a Flat Astragal. The "T" is attached to one of a pair of doors, which in classic Greek architecture was a bead around a column below the cap, is used for decorative purposes. Back Band A rabbeted moulding used to surround the outside edge of casing. Base Applied where floor and walls meet, forming a visual foundation. Protects walls from kicks, bumps, furniture and cleaning tools. Base may be referred to as one, two, or three member. The base shoe and base cap are used to conceal uneven floor and wall junctions. Base Cap A decorative member installed flush against the wall and the top of a S4S baseboard. Also a versatile panel moulding. Base Shoe Applied where base moulding meets the floor. Protects base moulding from damage by cleaning tools. Conceals any uneven lines or cracks where base meets the floor. Batten A symmetrical pattern used to conceal the line where two parallel boards or panels meet. Casing Used to trim inside and outside door and window openings. Brick Mould Is used as exterior door and window casing. It is a thick moulding, providing a surface for brick or other siding to butt against. Chair Rail An interior moulding usually applied about one third the distance from the floor, paralleling the base moulding and encircling the perimeter of a room. Originally used to prevent chairs from marring walls. Used today as a decorative element or a divider between different wall coverings, such as wallpaper and paint or wainscoting. A key decorative detail in traditional and colonial design. Corner Guard Outside corner guard is used to protect corners or the ragged edge where wallcovering and painted surfaces meet an outside corner. Inside corner guard covers uneven joints or ragged lines where wallpaper, paneling or other covering materials meets with painted or contrasting surfaced walls at an inside corner. Cove A moulding with a concave profile used at corners, particularly as a ceiling cornice. Small coves may be used as an inside corner guard. Crowns/Beds Most often used where walls and ceiling meet. Crown mouldings are used to cover larger angles. Crowns are always "sprung" while beds are either "sprung" or plain. A "sprung" moulding has the interior corner beveled off to better fit a right angle joint. Drip Cap Applied over exterior window and door frames, this moulding keeps water from seeping under the siding, also directs water away from window glass. Makes an attractive contemporary interior door and window casing. Half Round A moulding whose profile is half a circle. May be used as a screen moulding or bead, shelf edge or panel mould. Hand Rail Used as a hand support in a stairwell. Glass Bead Also called glass stop, cove and bead, putty bead, glazing bead, and staff bead. Used to hold glass in place. Lattice Originally used in trellis work, this small, plain S4S moulding is among the most versatile of profiles. Mullion Csg The strip which is applied over the window jambs in a multiple opening window. Sometimes called a panel strip, used for decorative wall treatments. Picture Mould Used to support hooks for picture hanging. Applied around a room's circumference near the ceiling line. Qtr Round Versatile quarter round may be used as a base shoe, inside corner moulding, or to cover 90° recessed junctures. Often used to cover the line where roof and siding meet on exteriors. Round A 360° round moulding, most often used as a closet pole. Screen Mould A panel moulding which covers the seam where screening is fastened to the screen frame. Also used as a shelf edge. Panel Mould A panel moulding is a decorative pattern, originally used to trim out raised panel wall constructional. It is most useful fabricated as a frame, surrounding attractive wall covering for a paneled effect on walls. Shingle Mould May be used in similar ways but originally was used on the rake of a building or around the exterior window frames. Stool A moulding interior trim member serving as a sash or window frame sill cap. Stop In door trim, stop is nailed to faces of the door frame to prevent the door from swinging through. A window trim, stop holds the bottom sash of a double hung window in place. Plycap Covers and beautifies plywood's rough sandwich edge in installation where it is exposed to view. Wainscot Cap Sometimes called a dado cap, this trims out the upper edge or top of a wainscot. Also called a wainscot moulding. Pipe and Fittings Terms: ABS – Acrylonitrile Butadiene Styrene ABS is the Outside Diameter (OD) of DWV Schedule 40. It is a plastic with high strength properties. Acme Threads The type of thread cut used on Plastic Trends’ molded BWV. Also called blunt thread. ADS Corrugated – Advanced Drainage Systems ADS Corrugated is the Outside Diameter (OD) of Profile pipe. Used for septic fields. ADS Smooth – Advanced Drainage Systems ADS Smooth is the Outside Diameter (OD) of Sewer SDR 35. Adapters A fitting that adapts from one system type to another, connecting different ODs (outside diameters) together. For example, SDR 35 Gasketed to DWV SCH40 or SDR 35 Gasketed to SDR 35 Solvent Weld. It can be HxH, GxG, GxH, GxS, SxG, or SxH. ASA – American Supply Association Association focusing primarily on plumbing (similar to AWWA). ASPE – The American Society of Plumbing Engineers ASPE is the international organization for professionals skilled in the design, specification and inspection of plumbing systems. ASPE is dedicated to the advancement of the science of plumbing engineering, to the professional growth and advancement of its members and the health, welfare and safety of the public. The Society disseminates technical data and information, sponsors activities that facilitate interaction with fellow professionals, and, through research and education, expands the base of knowledge of the plumbing engineering industry. ASPE members are leaders in innovative plumbing design, effective materials and energy use, and the application of advanced techniques throughout the world. (from aspe.org) Plastic Trends is a member of ASPE. ASTM – American Society for Testing and Materials American Consensus body that established standards for building products (all construction materials), including plumbing products. Made up of product producers, product end users and general interest people, such as engineers and specifiers. This body of people establishes, revises and maintains product standards to which Plastic Trends products are made. Plastic Trends is part of this body. ASTM does not certify products to meet its standards. We have certifications (CSA, NSF and UPC) for fittings produced to ASTM Standard D3034 and D2665 and typically the certifications should be displayed on every molded fitting. Occasionally, the certifications are included on adhesive labels when there is not enough space for engraving. AWWA – American Water Works Association Consists of people associated with water supply (waterworks), including all types of materials. This body writes product standards, such as C900/C905/C907. BOCA – Building Officials and Code Administrators Consensus based association that is similar to IAPMO. They are the plumbing and building code writing group. They write the codes then cities and states adopt them. Bushings One end is spigot and the other end is hub or gasket. The spigot end is the larger size and the hub or gasket is the smaller size. Bushings always reduce in size. There are concentric and eccentric bushings. Clamps Plastic Trends purchases stainless steel clamps for use with saddle tees and wyes. Components Anything used to make a fitting including raw material, labels, gaskets, locking rings, clamps, etc. Couplings Both ends are hub or gasket. In addition, both ends are the same system type. Coupling can maintain size on both ends or reduce in size. There are standard couplings (with a pipe stop), repair couplings (without a pipe stop), and increaser (or reducer) couplings. There are also eccentric couplings. CPVC – Chlorinated Polyvinyl Chloride A heat-resistant and low-combustibility plastic that is typically used in water supply. CSA – Canadian Standards Association CSA is the Canadian equivalent of ASTM. Royal Pipe is part of this body for plumbing products. Both Royal Pipe and Plastic Trends have representation on the electrical products body. Products marketed to meet CSA must be certified as such by CSA. Many of Plastic Trends’ products are CSA certified. CSA sets standards and certifies that products meet those standards. Downspout Adapters There are no existing specifications or standards on dimensions for downspouts. Downspout manufacturers make them to differing sizes – one manufacturer’s 3x4 downspout is not the same size as another’s 3x4 downspout. Plastic Trends designed their downspout adapter to accommodate the majority of sizes. Corrugated Downspout – will fit into spigot (not flush). DR 21 See SDR 21. DR 26 Pressure line used for irrigation. Available in sizes 10” through 24” and in white PVC. Meets ASTM D2241 and CSA B137.3. Specify DR 26 IPS Gasketed or Solvent Weld Pressure Series 160. This is not the same thing as SDR 26 sewer because it has a different OD (Outside Diameter) Drain Grate Goes inside a HUB. DWV – Drain, Waste, and Vent Non-pressure pipe and fittings used inside the house or building that convey waste water from fixtures (sinks, showers, toilets, etc.) to the outside sanitary sewer or septic line. HDPE – High Density Poly-Ethylene HDPE OD (Outside Diameter) = DWV OD HR – Hot Runner Premium grade of PVC which flows easier and smoother into a mold. It also increases the range from the melting point to the burning point while in the molding process. IAPMO – International Association of Plumbing and Mechanical Officials Regional (West Coast) plumbers’ union based association that writes and administers the Uniform Plumbing Code. Some areas of the country, such as California, require that plumbing products have IAPMO certification in order to be used there. Most Plastic Trends’ products are IAPMO certified. Installation Guidelines Please reference Uni-Bell’s Handbook of PVC Pipe or visit www.uni-bell.org. IPS – Iron Pipe Size IPS OD (Outside Diameter) = OD of DWV Schedule 40 IPS Thread The type of thread cut used on Plastic Trends’ threaded plugs. Also called NPT. These threads will not fit acme thread. ISO – International Organization for Standardization This association certifies a company’s ability to consistently manufacture quality products to ISO standards (ISO 9000, 9001, etc.) MCAA The Mechanical Contractors Association of America, Inc. (MCAA) is a vibrant, growing association of approximately 2,300 mechanical, plumbing, and service contractors. Members enjoy MCAA’s outstanding education programs, an expanding catalog of resources to help them manage and grow their businesses, periodicals and a website to keep them informed and connected, and business services to save them money. More info: http://www.mcaa.org MPPA – Michigan Plastic Processors Association Nitrile Gaskets Nitrile gaskets are only used when specified by an engineer. They are commonly used in applications where soil conditions are poor and the ground is saturated with petroleum based products. In this type of environment there is a possibility that contaminated soil could leach down into the sewer systems and eat away at the gaskets. Examples of such environments might be an airport, dump, refinery or landfill. Nitrile gaskets are resistant to solvents, oils and greases and are suitable for this type of application. The Nitrile gaskets are made by the same manufacturer that makes Plastic Trends’ standard SDR 35 gaskets. They have the same internal retainer. Plastic Trends can supply any of their STI™ fittings with these special gaskets. NSF – National Sanitation Foundation Nationally recognized testing laboratory that certifies plumbing products to meet the standard to which they were created. Many of Plastic Trends’ products are NSF certified. NUCA – National Utility Contractors Association NUCA is the largest trade association working solely for the underground utility construction industry. NUCA represents contractors, suppliers, and manufacturers involved in water, sewer, gas, electric, telecommunications, site work, and other segments of the industry across the country. Pipe Plastic Trends does not manufacture or stock pipe but Royal Pipe Systems in Woodbridge does. Hub –typically refers to a solvent weld joint that will fit over pipe or the spigot of another fitting. Can be sewer or schedule 40 DWV. Can be a pipe end or a fitting end. Bell –typically refers to a gasketed joint that will fit over pipe or the spigot of another fitting. Can be sewer SDR35, sewer SDR26, Profile, or C900. Can be a pipe end or a fitting end. PPFA – Plastic Pipe and Fittings Association Trade association consisting of all types of plastic pipe and/or fittings’ manufacturers. Created to promote the use of plastic in lieu of traditional materials such as concrete, cast iron, clay, etc. Plastic Trends is a member of this association. PVC – Polyvinyl Chloride The base plastic out of which Plastic Trends products are manufactured. This includes both pipe fittings and electrical fittings. SBR - Styrene-butadiene rubber. The most widely used elastomer for pipe and fitting gaskets worldwide. SDR or DR – Standard Dimension Ratio or Dimension Ratio A sewer pipe term that is used to determine the minimum wall thickness of pipe and fittings. SDR = Average Outside Diameter divided by the Minimum Wall Thickness. SDR = OD ÷ T. For example, Plastic Trends’ H306 is a 6” SDR 26 fitting. The minimum wall thickness of that fitting is 6.275 (sewer pipe dia.)/26 = .241 minimum wall. ASTM D3034 (the sewer pipe standard) lists SDRs 41, 35, 26 and 23.5. SDRs 35 and 26 are the predominant SDRs. The lower the SDR, the thicker the wall and thus the stronger the fitting. Plastic Trends is the only manufacture to offer a fitting with a wall thickness of SDR 14 through the body. SDR 21 IPS Gasketed and Solvent Weld Series 200 Pressure fittings. Available in sizes 10” through 24” and in white PVC. Meets ASTM D2241 and CSA B137.3. SDR 26 See Gasketed Heavy Wall Sewer SDR 26. Street 90 A Spigot by Hub or Spigot by Gasket 90 degree bend. TPE – Thermal Plastic Elastomer. Also called santoprene. It’s a rubber replacement. UL – Underwriter’s Laboratories UL is a nationally recognized testing laboratory that certifies consumer products for standard compliance and safety. Plastic Trends’ electrical parts are UL certified. ULC – Underwriter’s Laboratories Canada Canadian branch of Underwriter’s Laboratories. Plastic Trends’ electrical products for use in Canada are certified by ULC. Uni-bell PVC Pipe Association An association that consists of PVC pipe and fittings’ manufacturers. Created to promote and provide technical support in the use of PVC pipe and fittings. They write installation guidelines and are therefore used as a reference on product failures supporting improper installation. Plastic Trends is a member of this association. UPC – Uniform Plumbing Code The handbook for plumbing installation used by IAPMO. UPC – Uniform Product Code The governing body for bar code implementation. No relation to the Uniform Plumbing Code organization. Vent Tee Is another name for a straight tee. VCP – Verified Clay Pipe Warnock Hersey Canadian lab that is universally recognized in Canada. They certify products to CSA standards. This certification is an alternative to certification by CSA. Plastic Trends has CSA certification, not Warnock Hersey, at this time. WASDA – The Water and Sewer Distributors of America WASDA is comprised of over 100 distributors and manufacturers of waterworks and wastewater products. Formed in 1979, WASDA's promotes the waterworks/wastewater products distribution industry, while improving the image and professionalism of WASDA and its member companies. Plastic Trends is a member of WASDA. WEF – Water Environmental Federation WEF is similar to AWWA. Consists of people associated with water waste including all types of materials. Window & Door Terms: Aluminum-Clad Window A window with wood construction covered with aluminum sheet having a factory-applied finish (to provide a longer maintenance-free life). Angle Bay Window See Bay Window . Architrave The molded frame or ornament surrounding a window, door or other rectangular opening. ASHRAE American Society of Heating, Refrigerating & Air Conditioning Engineers, Inc., 1791 Tullie Circle, N.E. Atlanta, GA 30329. Toll-free for Customer Service: (800) 527-4723 (U.S. and Canada only). Phone: (404) 636-8400. Fax: (404) 321-5478 ASTM American Society for Testing and Materials, ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA, 19428-2959 USA. Phone: (610) 832-9585. Fax: (610) 832-9555. Astragal An interior molding attached to one of a pair of doors or side-hinged windows in order to prevent swing through; also used with sliding doors to ensure a tighter fit where the doors meet; often found on older casements or swinging screens. Awning Window A top-hinged sash. See Jal-Awning Window. Introduced in the 1950s. Balance See Sash Balance. Bar See Muntin. Basement Window – (Basement Sash) – (Cellar Sash) A wood or metal in-swinging sash that is hinged at either the top or the bottom. Bay Window Windows that project out from the wall and extend to the ground. An Angle Bay Window refers to the angle departure from the plane of the wall. See also Bow Window . Bottom Rail The bottom horizontal member of a window sash. Bow Window – (Compass Window) – (Radial Bay Window) A rounded bay window that projects from the wall in the shape of an arc; commonly consisting of five sash. See also Bay Window. Boxed Mullion A hollow mullion between two double-hung windows to hold the sash weight. Brick Molding A standard milled wood. B.T.U. – (Btu) An abbreviation for British Thermal Unit, commonly shown as “Btu”; the heat required to increase the temperature of one pound of water one degree Fahrenheit, about the heat from burning one wooden match. Butyl Tape See Sealant. Casement A window sash which swings open on side hinges; in-swinging are French in origin while out-swinging are from England. Casement Window A window with one or more casements. Casing – (Trim) Exposed molding or framing around a window or door, on either the inside or outside, to cover the space between the window frame or jamb and the wall. Caulking A mastic compound for filling joints and sealing cracks to prevent leakage of water and air; commonly made of silicone- bituminous- acrylic- or rubber-based materials. Celsius A centigrade scale of temperature measurement based on 0° as the freezing point and 100° as the boiling point of water. Abbreviated °C. Check Rail – (Meeting Rail) – (Lock Rail) The horizontal members (of a double-hung window) which come together. Circle Top Transom See Fanlight. Clerestory – (also Clearstory – High-Light Window) A window in the upper part of a lofty room that admits light to the center of the room. Coated Glass A window glass with an outside surface provided with a mirror reflective surface; the shading coefficient ranges from 20% to 45%. See Shading Coefficient . Colonial An architectural style associated with an early American period; Early American style c. 1730. Colonial Windows Windows with small rectangular panes, or divided lites, designated as 12-lite, 16-lite, etc. Combination Window Unit – (Combination Storm Sash and Screen) A window assembly containing a half screen and two glass storm panel; in frame, exposing the screen panel. Commercial Standard A voluntary set of rules and regulations covering quality of product (or installation), method of testing, rating of the product, certification, and labeling of manufactured products. Condensation The deposit of water vapor from the air on any cold surface whose temperature is below the dew point, such as a window glass or frame that is exposed to cold outdoor air. See Dew Point Temperature. Convection See Natural Convection and Forced Convection. A heat transfer process resulting from the circulation or movement of fluids, such as air. Cove Molding Trim molding with a concave face. Crack Perimeter The total length of the crack around a sash through which outdoor air could leak into the room. In a double-hung window, the total crackage is 3 times the width plus 2 times the height of the sash. Dado A rectangular slot or groove (with 3 surfaces) cut across the grain of a wood member, into which another board is fitted. See also Plough. Degree-Day A measure of heating demand, based on the difference between the mean daily outdoor temperature and 65°F. Cumulative totals for the month or heating season are used by engineers for estimating heating energy requirements. Design Heat Loss The calculated values, expressed in units of Btu per hour (abbreviated Btuh), for the heat transmitted from a warm interior to a cold outdoor condition, under some prescribed extreme weather conditions. The values are useful for selecting heating equipment and for estimating seasonal energy requirements. Infiltration heat loss is a part of the design heat loss. Desiccant A drying agent, such as silica gel, used by some manufacturers between the panes of insulating glass to prevent fogging between the panes. Dew Point Temperature The temperature of the air at which the water vapor in the air starts to condense in the form of liquid or as frost. Double-Hung Window Window with two vertically moving sashes, each closing a different part of the window. Double-Strength Glass Sheet glass with a thickness between 0.115” to 0.133” (3 to 3.38mm). Double Windows – (Double Glazing) Two windows, such as a regular window plus a storm sash; also an insulating window with air space between panes. Double Window Two windows separated by a mullion, forming a unit. Also called a coupled window. Drip Cap A horizontal molding to divert water from the top casing so that the water drips beyond the outside of the frame. Dry Glazing A form of glazing in which the glass is secured in the frame with a dry gasket, wood stops, or metal stops, instead of by a glazing compound. See also Reglet. Emergency Exit Window – (Egress Window) Fire escape window; large enough for a person to climb out; each bedroom should be provided with exit windows. Extension Jamb – (Jamb Lining) – (Jamb Extender) A board used to increase the depth of the jambs of a window frame to fit a wall of any given thickness. Exterior Casing See Casing. Fasteners Devices for jointing two parts together, such as screws nails and bolts. Fenestration The placement of window openings in a building wall; one of the important elements in controlling the exterior appearance of a building. Finish Casing – (Finish Trim) Interior trim boards around a window unit. Fire-Escape Window – (Emergency Exit Window) Window which opens onto fire escape; window designed for emergency exit. Fixed Light – (Fixed Sash) Window which is non-operative (does not open). Flashing Sheet metal provided for drainage of water and to prevent water penetration into building. Flat Glass – (Window Glass) – (Plate Glass) – (Float Glass) – (Rolled Glass) – (Cylinder Glass) Glass sold in flat sheets and named according to the method used in its manufacture. Float Glass Smooth glass formed on the top of molten tin surface; a flat glass sheet. Frame See Window Frame. French Window Two casement sash hinged on the sides to open in the middle; the sash extends to the floor and serves as a door to a porch or terrace. Forced Convection A heat transfer process, aided by mechanical circulation of a liquid (such as water) or a gas (such as air). This applies to natural wind flow over a window. Glass An elastic transparent material composed of silica (sand), soda (sodium carbonate), and lime (calcium carbonate) with small quantities of aluminum, boric, or magnesia oxides. See Flat Glass. Glazing The installation of glass in a window opening; also the fenestration or windows. Glazing Bead – (Glass Stop) – (Wood Stop) – (Sill Bead) A removable trim that holds the glass in place. Glazing Channel A groove cut into the sash for the mounting of glass. Glazing Rabbet See Rabbet. Grilles See Muntin . Groove A long, narrow cut on the face of a wood member; a groove across the grain is a Dado; one parallel with the grain is a Plough. A groove exposes three surfaces, in contrast with the two surfaces exposed in a Rabbet or Notching. See Rabbetted Joint and Plough. Hanging Mounting a sash in its frame. Hanging Sash – (Hung Sash) Sash hung on a cord connected to a counterweight. Head The top or upper member of any element or structure; in windows, it refers to the top of the frame, as in Round Head Window. See Head Jamb. Head Jamb(Head) All of the horizontal members at the top of the window frame. Header – (Lintel) – (Beam) Supporting member or beam above window opening which transfers building weight above to the supporting wall structure on each side of the window. The term header is generally in reference to a wood beam, whereas Lintel often refers to a steel beam. Head Rail - See Rail. Heat-Absorbing Glass – (Tinted Glass)Heat-Absorbing Glass Window glass containing chemicals (with gray, bronze, or blue-green tint) which absorb light and heat radiation, and reduce glare and brightness. Shading coefficient of this glass varies from about 50% to 70%. Heat Transfer Coefficient – (U-value) A value indicating the rate of heat flow through a building construction, expressed in units of 'Btuh per square foot of surface per degree F. difference between indoor and outdoor air temperature.' This is numerically equal to the 'inverse of the sum of R-values' for the construction. Hinge A movable joint enabling a window to swing open. Hopper Light – (Hopper Vent) - (Hopper Ventilator) Inward opening sash hinged at the bottom. Horizontal Sliding Window (Horizontal Slider) Windows which slide horizontally. Hung Sash See Hanging Sash. Hung Window Window with one or more hanging sashes. Hygroscopic The ability to 'give off' and 'take on' moisture, as in wood exposed to changes in relative humidity of air. Insect Screen – (Window Screen) - (Screen) Woven mesh of metal, plastic, or fiberglass stretched over a window opening to permit air to pass through, but not insects. Inside Casing (Interior Casing) - (Interior Finish) -(Interior Trim) - The inside visible molding surrounding the interior of the window frame, See Casing. Inside Trim See Inside Casing. Inside Sill See Stool . Insulating Glass Double- or triple-glazing with an enclosed, dehydrated, and hermetically sealed air space between the panes; the space is commonly from 3/16" to ¾". Insulated Window A window with multiple glazing that provides one or more air spaces between layers of glazing. Interior Finish See Inside Casing. Interior Glazes Glazing installed from inside of building. Interior Mullion Casing The inside trim between adjacent windows. See Mullion. Jal Awning – (Awning Window) Window with several out-swinging, awning-type windows that pivot near the top of the glass and operate in unison. Jamb A vertical member at the side of the window frame; also refers to the horizontal member at the top of the window frame, as in Head Jamb and Window Jamb. Jamb All of the vertical members at the side of the window frame. Jamb Depth Width of the window frame from inside to outside. Jamb Extender See Extension Jamb. Knocked-Down Not assembled; parts for a window frame pre-manufactured for assembly at a later Laminated Glass – See Shatter-Proof Glass. Latch – (Catch) – (Lock) A device which holds a window shut, such as the latch at the meeting rail of a double-hung window or one mounted on the stile of casement windows, often referred to as a lock. Lead Light – (Lead Glazing) – (Stained Glass) Window with small panes of glass set in grooved rods of cast lead (or came). The glass can be clear, color, or stained. Light – (Lite) A window; a pane of glass within a window. Double-hung windows are designated by the number of lights in upper and lower sash, as in six-over-six. Lintel Horizontal member (wood, steel, or stone) over a window opening to support the weight of the wall above (See also Header). Lock A fastening device in which a bolt is secured and can be operated by a key. Commonly used to refer to Latches or Catches. Lock Rail See Meeting Rail. Lock Stile The vertical member (stile) of a casement sash which closes against the surrounding frame. Low-Emissivity Coating (Low-E) Coating for glass surfaces which reflects radiant heat energy rather than allowing that energy to radiate through the glass surface. The lower the emissivity of the glass the lower the heat transfer coefficient. Lunette A crescent-shaped window framed by moldings or an arch. Meeting Rail – (Lock Rail) One of the two horizontal members of a double-hung sash which come together See Check Rail. Member Any structural part of a window, such as a rail, stile, or lintel. Millwork Window sash and other wood products made in a wood-working plant. Miter Joint Two members joined at an angle, commonly 45 degrees. Moisture Barrier – (Vapor Barrier) A material which retards the passage of water vapor from one space to another. Polyethylene sheet is commonly used as a vapor retarder. Moisture Content Percentage of dry weight of material which is composed of water, such as in wood. Mold – (Molding) A relatively narrow strip of wood used to conceal a joint or to emphasize ornamentation of a structure. Mould – (Moulding) British spelling of mold, and molding. Mullion Vertical member between window units. Muntin – (Sash Bar) – (Window Bar) – (Glazing Bar) a secondary framing member (horizontal, vertical, or slanted) to hold the window panes in the sash. This term is often confused with Mullion. Muntin Grilles Wood, plastic, or metal grilles. Multi-Lite Sash A sash divided into many lites. Mylar Trade name for a clear, durable plastic sheet used for covering an inside storm panel or for removable, roll-up glazing over an entire window frame. Natural Convection A heat transfer process involving motion in a fluid (such as air) caused by difference in density of the fluid and the action of gravity This is an important part of heat transfer from the glass surface to room air. See Forced Convection. Notching A rectangular cut across the grain of the wood member at the end of the board (See Rabbet). Obscure Glass (Visionproof Glass) - Any textured glass (frosted, etched, fluted, ground, etc.) used for privacy, light diffusion, or decorative effects. Operator Crank-operated device for opening and closing casement or jalousie windows. Oriel Window A window projecting from the wall and carried on brackets, corbels, or a cantilever. Unlike a Bay Window, the projection of an Oriel does not extend all the way to the ground. Orientation The placement of a room, window, or building with respect to sun, wind, earth, access, or view (See also Solar Orientation). Outside Casing (Outside Facing) - (Outside Trim) - (Exterior Casing) - That portion of the window frame which is exposed to the outdoors, See Casing. Outside Glazing Glazing installed from the outside. Pane A sheet of glass for glazing a window. After installation, the pane is referred to as a 'light' (lite) or 'window light.' Parting Bead – (Parting Strip) – (Parting Stop) A vertical strip on each jamb that separates the sashes of a double-hung window. Patterned Glass One or both surfaces of glass with a rolled design; used for privacy and light diffusion. Percentage Humidity Weight of water vapor in air divided by weight of vapor contained in saturated air, expressed as a percentage. Picture Window Large fixed windows; introduced in the 1940s. Plastics Artificial substances made of organic polymers that can be extruded or molded into various shapes, some of which have been adapted to windows. The material is commonly stiffer than rubber. Plough – (Plow) A rectangular groove or slot (with 3 surfaces) cut parallel with the grain (See Dado). Polyvinylchloride See PVC. Prime Sash The balanced or moving sash of a window unit. Prime Window Window with single or multiple glazing to which storm sash may be installed. Projected Window An awning-type window that swings either inwards or outwards at the top or the bottom. The 'PIB' or 'project in at bottom' window can be cleaned from the inside. Psychrometric Chart A chart which shows dry bulb and wet bulb temperatures used to determine the relative humidity of air and the dew point temperature. Other engineering data referring to moisture in air are also shown. PVC (Polyvinylchloride) - An extruded or molded plastic material used for window framing and as a thermal barrier for aluminum windows. Radiation The transmission of energy through space without heating the air between, as in Solar Radiation. Rabbet A rectangular notch (consisting of two surfaces) cut parallel with the grain of wood along the edge. See Notching. Rabbetted Joint The joint formed by two boards with rabbetted ends, as in some window frames. Rail – (Head Rail) – (Top Rail) – (Bottom Rail) – (Meeting Rail) Horizontal member of a window sash. Reflective Glass Window glass coated to reflect radiation striking the surface of the glass. Reglet A plastic or wood molding placed in a concrete or masonry opening to provide a uniform groove for a spline-type gasket to hold window glass. See Dry Glazing. Relative Humidity Weight of water vapor in air divided by the weight of water vapor in completely saturated air at the same temperature, expressed as a percentage. R-Value – (Thermal Resistance) A measure of resistance to heat flow of a material or construction; a higher value indicates a better heat insulating property. The R-value of an ordinary single-pane sash with a 15 mph wind on one side is about 0.9. Safety Glass A strengthened or reinforced glass that is less subject to breakage or splintering, such as glass for storm doors and some windows. See Tempered Glass, Shatterproof Glass, and Plexiglas. Sash - (Window Sash) Framework of stiles and rails in which the lights of a window are set. Sash and Frame A window and its casing frame. Sash Balance A device for counter-balancing a sash of a double-hung window to hold it in the up position. Sash Stop A molding that covers the joint between window sash and the jamb. Screen See Insect Screen. Screen – (Wire Cloth) A close-mesh woven screening material of metal, plastic, or fiberglass for a window screen, to block the entry of insects but permit light, air, and vision through the screen. Sealant A compressible plastic material used to seal any opening or junction of two parts, such as between the glass and a metal sash, commonly made of silicone, butyl tape, or polysulfide. Sealed Double Glass Two panes separated by a sealed space. See also Insulating Glass. Shade Screen – (Sun Screen) A specially fabricated window screen of sheet material with small narrow louvers formed in place to intercept solar radiation striking a window; the louvers are so small that only extremely small insects can pass through. Also, an awning with fixed louvers of metal or wood construction. Shading Coefficient A decimal value which is the solar gain of a window, divided by the solar gain for a clear single-glass window of the same size. The shading coefficient of clear, double-glazing is about 0.85 to 0.9. Shatter-Proof Glass – (Laminated Glass) Two sheets of glass with a transparent plastic sheet sandwiched between to form a pane resistant to shattering. Side Light – (Margin Light) A fixed, often narrow, glass window next to a door opening (or window). Silicone – (Silicone Sealer) An enduring sealing agent that resists water. See Sealant. Sill – (Sill Plate) – (Inside Sill) – (Outside Sill) The horizontal members at the bottom of the window frame; a masonry sill or sub-sill can be below the sill of the window unit. Single-Hung Window A window that is similar to a double-hung window except that the top sash is stationary. Single-Strength Glass Glass with thickness between 0.085 to 0.100" (2.16 mm to 2.57 mm). Sliding Sash – (Sliding Windows) A window which moves horizontally in grooves or tracks. Sling Psychrometer A measuring instrument with two thermometers (dry-bulb and wet-bulb) used for determining the dewpoint and relative humidity of air; its relation to windows is ascertaining the point at which moisture will condense on the inside surface of the glass. See Psychrometric Chart. Solar Heat Gain Heat from solar radiation that enters a building. Solar Orientation A building placed on a lot so that the long dimension faces south and a majority of the windows are south-facing. Sound-Insulating Glass – (Sound-Resistive Glass) Double glass fixed on resilient mountings and separated so as to reduce sound transmission. Sound-Resistive Glass See Sound-lnsulating Glass. Spacer The linear object that separates and maintains the space between the glass surfaces of insulating glass. Spiral Balance See Sash Balance. Spline A rectangular strip of wood or metal inserted between two boards, which have been slotted to receive it. Spring Bolt A fastener for holding the sash in a fixed location by means of a spring-loaded bolt in the stile entering a hole in the jamb. Stacked Window Units A combined grouping of awning, hopper, casement, or non-operative windows to form a large glazed unit. Stained Glass Window A window with a painted scene or pattern that has been fired into the glass. Windows with plain colored glass set in lead are also called stained glass. See Lead Light. Stationary Sash A fixed sash; also referred to as a picture, studio, vista, or view sash. Stile The vertical-edge members of a window sash. Stool A shelf-like board of the interior part of the window sill, against which the bottom rail of the sash closes. Stop – (Bead, Side Stop, Window Stop, Parting Stop) The molding on the inside of the window frame against which the window sash closes, or in the case of a double-hung window, the sash slides against the stop. Storm Sash – (Storm Window) An extra window on the outside to protect an existing window, but mainly to increase the thermal resistance of the window. Sunburst Light See Fan Light. Sun Screen See Shade Screen. Sweep Lock A sash fastener located at the meeting rails of a double-hung window, which rotates and clamps the two rails closer together. Tape Balance See Sash Balance. Tempered Glass Special heat-treated, high-strength safety glass which shatters into pebble-sized particles but not into slivers. Therm In technical usage, the term is a convenient measure of heating value, namely 100,000 Btu. One therm is roughly equivalent to the heating value of 100 cubic feet of natural (methane) gas. Thermal Barrier (Thermal Break) - A material of high thermal resistance placed between two metal sash, or installed between adjoining metal framing of metal windows, in order to reduce thermal conduction from indoors to outdoors. Thermal Conduction Heat transfer through a material by contact of one molecule to the next. Heat flows from a high temperature area to one of lower temperature. Thermal Conductivity Heat transfer property of materials expressed in units of 'Btu per hour per inch of thickness per square foot of surface per one degree F. temperature difference.' Referred to by the letter 'k.' Thermal Conductance Same as Thermal Conductivity except thickness is 'as stated' rather than one inch. Referred to by the letter 'C.' Thermal Insulation A material that resists heat flow. Material having a high R-value. Thermal Resistance – (R-value) A property of a substance or construction which retards the flow of heat; one measure of this property is R-value. See Heat Transfer Coefficient. Tinted Glass See Heat-Absorbing Glass. Top Rail See Rail . Transom (Transom Bar) - A horizontal member separating a door from a window panel above the door, or separating one window above another. Transom Light (Transom Window) - The window sash located above a door. Trim Visible molding surrounding a window opening. See Casing. Triple Glazing Three panes of glass with two air spaces between, commonly consisting of an insulating glass with a separate storm sash. Also available as an Insulating Window in a single frame. Triple Window A term generally referring to any tripartite group of windows with square heads. These are frequently found on Colonial Revival houses; they suggest Palladian Windows but are less expensive to build. Ultra-violet Radiation Extremely short wave length invisible radiation, which is a component of solar radiation, and merges into the visible spectrum; attributed as a source of skin sunburn and color fading of draperies and carpeting. U-value A value indicating the rate of heat flow through a building construction, expressed in units of 'Btuh per square foot of surface per degree F. difference between indoor and outdoor air temperature.' This is numerically equal to the 'inverse of the sum of R-values' for the construction. Also see Heat Transfer Coefficient. Vapor Barrier – (Vapor Retarder) A membrane or coating which resists passage of water vapor from a region of high vapor pressure to low pressure, more accurately called a Vapor Retarder. Vertical Sliding Window One or more sashes that move in a vertical direction. Vinyl See PVC. Visible Spectrum That portion of the total radiation that is visible to the human eye and which lies between the ultra-violet and the infra-red portions of the electromagnetic spectrum. The colors associated with the visible spectrum range from violet, indigo, blue, green, yellow, orange, through red. Weatherstrip A strip of resilient material for covering the joint between the window sash and frame in order to reduce air leaks and prevent water from entering the structure. Weathertight Sealed to prevent entry of air and precipitation into the structure. Weephole Small holes drilled along the bottom edge of storm sash or combination storm-screens to permit moisture condensation or wind-driven rain to drain away from the sill to the outdoors. Window A glazed opening in an external wall; an entire unit consisting of a frame, sash and glazing, and any operable elements. Window Bar See Muntin. Window Frame The fixed frame of a window, which holds the sash or casement as well as hardware. Window Hardware Various devices and mechanisms for the window including: catches, cords and chains, fasteners and locks, hinges and pivots, lifts and pulls, pulleys and sash weights, sash balances, and stays. Window Unit A complete window with sash and frame.

Resources

Glossary of Terms

Trim and Mouldings Terms
Pipe and Fittings Terms
Window & Door Terms

Trim and Mouldings Terms:

Cellular Vinyl and Polymer Mouldings
Royal Mouldings has pioneered the marketing, promotion, and manufacturing of the Cellular process. This process uses specially formulated resins, such as PVC or Polystyrene allowing them to expand to a "full size" profile with a strong inner cell and outside surface that emulates the strength benefits of wood without the natural defects of wood. There are no surface blemishes and only minimal on-going maintenance. The products do not rot and are available in the Industry's largest selection of finishes.

Cellular Vinyl
An extruded PVC profile with a solid outer skin and strong durable cellular core.

Clearwood®PS
A patented ready to finish process designed to give a defect free surface for painting, staining and Faux finishing with the look of natural wood. Clearwood also can be painted with oil or latex paint.

Readi Finish®
A patented finish that does not require painting and is guaranteed for 10 years against UV discoloration.

BASIC PROFILES AND USES
(Courtesy Wood Moulding & Millwork Producers)

Astragal
This moulding includes two different types, a T-Astragal and a Flat Astragal. The "T" is attached to one of a pair of doors, which in classic Greek architecture was a bead around a column below the cap, is used for decorative purposes.

Back Band
A rabbeted moulding used to surround the outside edge of casing.

Base
Applied where floor and walls meet, forming a visual foundation. Protects walls from kicks, bumps, furniture and cleaning tools. Base may be referred to as one, two, or three member. The base shoe and base cap are used to conceal uneven floor and wall junctions.

Base Cap
A decorative member installed flush against the wall and the top of a S4S baseboard. Also a versatile panel moulding.

Base Shoe
Applied where base moulding meets the floor. Protects base moulding from damage by cleaning tools. Conceals any uneven lines or cracks where base meets the floor.

Batten
A symmetrical pattern used to conceal the line where two parallel boards or panels meet.

Casing
Used to trim inside and outside door and window openings.

Brick Mould
Is used as exterior door and window casing. It is a thick moulding, providing a surface for brick or other siding to butt against.

Chair Rail
An interior moulding usually applied about one third the distance from the floor, paralleling the base moulding and encircling the perimeter of a room. Originally used to prevent chairs from marring walls. Used today as a decorative element or a divider between different wall coverings, such as wallpaper and paint or wainscoting. A key decorative detail in traditional and colonial design.

Corner Guard
Outside corner guard is used to protect corners or the ragged edge where wallcovering and painted surfaces meet an outside corner. Inside corner guard covers uneven joints or ragged lines where wallpaper, paneling or other covering materials meets with painted or contrasting surfaced walls at an inside corner.

Cove
A moulding with a concave profile used at corners, particularly as a ceiling cornice. Small coves may be used as an inside corner guard.

Crowns/Beds
Most often used where walls and ceiling meet. Crown mouldings are used to cover larger angles. Crowns are always "sprung" while beds are either "sprung" or plain. A "sprung" moulding has the interior corner beveled off to better fit a right angle joint.

Drip Cap
Applied over exterior window and door frames, this moulding keeps water from seeping under the siding, also directs water away from window glass. Makes an attractive contemporary interior door and window casing.

Half Round
A moulding whose profile is half a circle. May be used as a screen moulding or bead, shelf edge or panel mould.

Hand Rail
Used as a hand support in a stairwell.

Glass Bead
Also called glass stop, cove and bead, putty bead, glazing bead, and staff bead. Used to hold glass in place.

Lattice
Originally used in trellis work, this small, plain S4S moulding is among the most versatile of profiles.

Mullion Csg
The strip which is applied over the window jambs in a multiple opening window. Sometimes called a panel strip, used for decorative wall treatments.

Picture Mould
Used to support hooks for picture hanging. Applied around a room's circumference near the ceiling line.

Qtr Round
Versatile quarter round may be used as a base shoe, inside corner moulding, or to cover 90° recessed junctures. Often used to cover the line where roof and siding meet on exteriors.

Round
A 360° round moulding, most often used as a closet pole.

Screen Mould
A panel moulding which covers the seam where screening is fastened to the screen frame. Also used as a shelf edge.

Panel Mould
A panel moulding is a decorative pattern, originally used to trim out raised panel wall constructional. It is most useful fabricated as a frame, surrounding attractive wall covering for a paneled effect on walls.

Shingle Mould
May be used in similar ways but originally was used on the rake of a building or around the exterior window frames.

Stool
A moulding interior trim member serving as a sash or window frame sill cap.

Stop
In door trim, stop is nailed to faces of the door frame to prevent the door from swinging through. A window trim, stop holds the bottom sash of a double hung window in place.

Plycap
Covers and beautifies plywood's rough sandwich edge in installation where it is exposed to view.

Wainscot Cap
Sometimes called a dado cap, this trims out the upper edge or top of a wainscot. Also called a wainscot moulding.

Pipe and Fittings Terms:

ABS – Acrylonitrile Butadiene Styrene
ABS is the Outside Diameter (OD) of DWV Schedule 40. It is a plastic with high strength properties.

Acme Threads
The type of thread cut used on Plastic Trends’ molded BWV. Also called blunt thread.

ADS Corrugated – Advanced Drainage Systems
ADS Corrugated is the Outside Diameter (OD) of Profile pipe. Used for septic fields.

ADS Smooth – Advanced Drainage Systems
ADS Smooth is the Outside Diameter (OD) of Sewer SDR 35.

Adapters
A fitting that adapts from one system type to another, connecting different ODs (outside diameters) together. For example, SDR 35 Gasketed to DWV SCH40 or SDR 35 Gasketed to SDR 35 Solvent Weld. It can be HxH, GxG, GxH, GxS, SxG, or SxH.

ASA – American Supply Association
Association focusing primarily on plumbing (similar to AWWA).

ASPE – The American Society of Plumbing Engineers
ASPE is the international organization for professionals skilled in the design, specification and inspection of plumbing systems. ASPE is dedicated to the advancement of the science of plumbing engineering, to the professional growth and advancement of its members and the health, welfare and safety of the public. The Society disseminates technical data and information, sponsors activities that facilitate interaction with fellow professionals, and, through research and education, expands the base of knowledge of the plumbing engineering industry. ASPE members are leaders in innovative plumbing design, effective materials and energy use, and the application of advanced techniques throughout the world. (from aspe.org) Plastic Trends is a member of ASPE.

ASTM – American Society for Testing and Materials
American Consensus body that established standards for building products (all construction materials), including plumbing products. Made up of product producers, product end users and general interest people, such as engineers and specifiers. This body of people establishes, revises and maintains product standards to which Plastic Trends products are made. Plastic Trends is part of this body. ASTM does not certify products to meet its standards. We have certifications (CSA, NSF and UPC) for fittings produced to ASTM Standard D3034 and D2665 and typically the certifications should be displayed on every molded fitting. Occasionally, the certifications are included on adhesive labels when there is not enough space for engraving.

AWWA – American Water Works Association
Consists of people associated with water supply (waterworks), including all types of materials. This body writes product standards, such as C900/C905/C907.

BOCA – Building Officials and Code Administrators
Consensus based association that is similar to IAPMO. They are the plumbing and building code writing group. They write the codes then cities and states adopt them.

Bushings
One end is spigot and the other end is hub or gasket. The spigot end is the larger size and the hub or gasket is the smaller size. Bushings always reduce in size. There are concentric and eccentric bushings.

Clamps
Plastic Trends purchases stainless steel clamps for use with saddle tees and wyes.

Components
Anything used to make a fitting including raw material, labels, gaskets, locking rings, clamps, etc.

Couplings
Both ends are hub or gasket. In addition, both ends are the same system type. Coupling can maintain size on both ends or reduce in size. There are standard couplings (with a pipe stop), repair couplings (without a pipe stop), and increaser (or reducer) couplings. There are also eccentric couplings.

CPVC – Chlorinated Polyvinyl Chloride
A heat-resistant and low-combustibility plastic that is typically used in water supply.

CSA – Canadian Standards Association
CSA is the Canadian equivalent of ASTM. Royal Pipe is part of this body for plumbing products. Both Royal Pipe and Plastic Trends have representation on the electrical products body. Products marketed to meet CSA must be certified as such by CSA. Many of Plastic Trends’ products are CSA certified. CSA sets standards and certifies that products meet those standards.

Downspout Adapters
There are no existing specifications or standards on dimensions for downspouts. Downspout manufacturers make them to differing sizes – one manufacturer’s 3x4 downspout is not the same size as another’s 3x4 downspout. Plastic Trends designed their downspout adapter to accommodate the majority of sizes. Corrugated Downspout – will fit into spigot (not flush).

DR 21
See SDR 21.

DR 26
Pressure line used for irrigation. Available in sizes 10” through 24” and in white PVC. Meets ASTM D2241 and CSA B137.3. Specify DR 26 IPS Gasketed or Solvent Weld Pressure Series 160. This is not the same thing as SDR 26 sewer because it has a different OD (Outside Diameter)

Drain Grate
Goes inside a HUB.

DWV – Drain, Waste, and Vent
Non-pressure pipe and fittings used inside the house or building that convey waste water from fixtures (sinks, showers, toilets, etc.) to the outside sanitary sewer or septic line.

HDPE – High Density Poly-Ethylene
HDPE OD (Outside Diameter) = DWV OD

HR – Hot Runner
Premium grade of PVC which flows easier and smoother into a mold. It also increases the range from the melting point to the burning point while in the molding process.

IAPMO – International Association of Plumbing and Mechanical Officials
Regional (West Coast) plumbers’ union based association that writes and administers the Uniform Plumbing Code. Some areas of the country, such as California, require that plumbing products have IAPMO certification in order to be used there. Most Plastic Trends’ products are IAPMO certified.

Installation Guidelines
Please reference Uni-Bell’s Handbook of PVC Pipe or visit www.uni-bell.org.

IPS – Iron Pipe Size
IPS OD (Outside Diameter) = OD of DWV Schedule 40

IPS Thread
The type of thread cut used on Plastic Trends’ threaded plugs. Also called NPT. These threads will not fit acme thread.

ISO – International Organization for Standardization
This association certifies a company’s ability to consistently manufacture quality products to ISO standards (ISO 9000, 9001, etc.)

MCAA
The Mechanical Contractors Association of America, Inc. (MCAA) is a vibrant, growing association of approximately 2,300 mechanical, plumbing, and service contractors. Members enjoy MCAA’s outstanding education programs, an expanding catalog of resources to help them manage and grow their businesses, periodicals and a website to keep them informed and connected, and business services to save them money. More info: http://www.mcaa.org

MPPA – Michigan Plastic Processors Association

Nitrile Gaskets
Nitrile gaskets are only used when specified by an engineer. They are commonly used in applications where soil conditions are poor and the ground is saturated with petroleum based products. In this type of environment there is a possibility that contaminated soil could leach down into the sewer systems and eat away at the gaskets. Examples of such environments might be an airport, dump, refinery or landfill. Nitrile gaskets are resistant to solvents, oils and greases and are suitable for this type of application. The Nitrile gaskets are made by the same manufacturer that makes Plastic Trends’ standard SDR 35 gaskets. They have the same internal retainer. Plastic Trends can supply any of their STI™ fittings with these special gaskets.

NSF – National Sanitation Foundation
Nationally recognized testing laboratory that certifies plumbing products to meet the standard to which they were created. Many of Plastic Trends’ products are NSF certified.

NUCA – National Utility Contractors Association
NUCA is the largest trade association working solely for the underground utility construction industry. NUCA represents contractors, suppliers, and manufacturers involved in water, sewer, gas, electric, telecommunications, site work, and other segments of the industry across the country.

Pipe
Plastic Trends does not manufacture or stock pipe but Royal Pipe Systems in Woodbridge does.
Hub –typically refers to a solvent weld joint that will fit over pipe or the spigot of another fitting. Can be sewer or schedule 40 DWV. Can be a pipe end or a fitting end.
Bell –typically refers to a gasketed joint that will fit over pipe or the spigot of another fitting. Can be sewer SDR35, sewer SDR26, Profile, or C900. Can be a pipe end or a fitting end.

PPFA – Plastic Pipe and Fittings Association
Trade association consisting of all types of plastic pipe and/or fittings’ manufacturers. Created to promote the use of plastic in lieu of traditional materials such as concrete, cast iron, clay, etc. Plastic Trends is a member of this association.

PVC – Polyvinyl Chloride
The base plastic out of which Plastic Trends products are manufactured. This includes both pipe fittings and electrical fittings.

SBR - Styrene-butadiene rubber.
The most widely used elastomer for pipe and fitting gaskets worldwide.

SDR or DR – Standard Dimension Ratio or Dimension Ratio
A sewer pipe term that is used to determine the minimum wall thickness of pipe and fittings. SDR = Average Outside Diameter divided by the Minimum Wall Thickness. SDR = OD ÷ T. For example, Plastic Trends’ H306 is a 6” SDR 26 fitting. The minimum wall thickness of that fitting is 6.275 (sewer pipe dia.)/26 = .241 minimum wall. ASTM D3034 (the sewer pipe standard) lists SDRs 41, 35, 26 and 23.5. SDRs 35 and 26 are the predominant SDRs. The lower the SDR, the thicker the wall and thus the stronger the fitting. Plastic Trends is the only manufacture to offer a fitting with a wall thickness of SDR 14 through the body.

SDR 21
IPS Gasketed and Solvent Weld Series 200 Pressure fittings. Available in sizes 10” through 24” and in white PVC. Meets ASTM D2241 and CSA B137.3.

SDR 26
See Gasketed Heavy Wall Sewer SDR 26.

Street 90
A Spigot by Hub or Spigot by Gasket 90 degree bend.

TPE – Thermal Plastic Elastomer.
Also called santoprene. It’s a rubber replacement.

UL – Underwriter’s Laboratories
UL is a nationally recognized testing laboratory that certifies consumer products for standard compliance and safety. Plastic Trends’ electrical parts are UL certified.

ULC – Underwriter’s Laboratories Canada
Canadian branch of Underwriter’s Laboratories. Plastic Trends’ electrical products for use in Canada are certified by ULC.

Uni-bell PVC Pipe Association
An association that consists of PVC pipe and fittings’ manufacturers. Created to promote and provide technical support in the use of PVC pipe and fittings. They write installation guidelines and are therefore used as a reference on product failures supporting improper installation. Plastic Trends is a member of this association.

UPC – Uniform Plumbing Code
The handbook for plumbing installation used by IAPMO.

UPC – Uniform Product Code
The governing body for bar code implementation. No relation to the Uniform Plumbing Code organization.

Vent Tee
Is another name for a straight tee.

VCP – Verified Clay Pipe

Warnock Hersey
Canadian lab that is universally recognized in Canada. They certify products to CSA standards. This certification is an alternative to certification by CSA. Plastic Trends has CSA certification, not Warnock Hersey, at this time.

WASDA – The Water and Sewer Distributors of America
WASDA is comprised of over 100 distributors and manufacturers of waterworks and wastewater products. Formed in 1979, WASDA's promotes the waterworks/wastewater products distribution industry, while improving the image and professionalism of WASDA and its member companies. Plastic Trends is a member of WASDA.

WEF – Water Environmental Federation
WEF is similar to AWWA. Consists of people associated with water waste including all types of materials.

Window & Door Terms:

Aluminum-Clad Window
A window with wood construction covered with aluminum sheet having a factory-applied finish (to provide a longer maintenance-free life).

Angle Bay Window
See Bay Window .

Architrave
The molded frame or ornament surrounding a window, door or other rectangular opening.

ASHRAE
American Society of Heating, Refrigerating & Air Conditioning Engineers, Inc., 1791 Tullie Circle, N.E. Atlanta, GA 30329. Toll-free for Customer Service: (800) 527-4723 (U.S. and Canada only). Phone: (404) 636-8400. Fax: (404) 321-5478

ASTM
American Society for Testing and Materials, ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA, 19428-2959 USA. Phone: (610) 832-9585. Fax: (610) 832-9555.

Astragal
An interior molding attached to one of a pair of doors or side-hinged windows in order to prevent swing through; also used with sliding doors to ensure a tighter fit where the doors meet; often found on older casements or swinging screens.

Awning Window
A top-hinged sash. See Jal-Awning Window. Introduced in the 1950s.

Balance
See Sash Balance.

Bar
See Muntin.

Basement Window – (Basement Sash) – (Cellar Sash)
A wood or metal in-swinging sash that is hinged at either the top or the bottom.

Bay Window
Windows that project out from the wall and extend to the ground. An Angle Bay Window refers to the angle departure from the plane of the wall. See also Bow Window .

Bottom Rail
The bottom horizontal member of a window sash.

Bow Window – (Compass Window) – (Radial Bay Window)
A rounded bay window that projects from the wall in the shape of an arc; commonly consisting of five sash. See also Bay Window.

Boxed Mullion
A hollow mullion between two double-hung windows to hold the sash weight.

Brick Molding
A standard milled wood.

B.T.U. – (Btu)
An abbreviation for British Thermal Unit, commonly shown as “Btu”; the heat required to increase the temperature of one pound of water one degree Fahrenheit, about the heat from burning one wooden match.

Butyl Tape
See Sealant.

Casement
A window sash which swings open on side hinges; in-swinging are French in origin while out-swinging are from England.

Casement Window
A window with one or more casements.

Casing – (Trim)
Exposed molding or framing around a window or door, on either the inside or outside, to cover the space between the window frame or jamb and the wall.

Caulking
A mastic compound for filling joints and sealing cracks to prevent leakage of water and air; commonly made of silicone- bituminous- acrylic- or rubber-based materials.

Celsius
A centigrade scale of temperature measurement based on 0° as the freezing point and 100° as the boiling point of water. Abbreviated °C.

Check Rail – (Meeting Rail) – (Lock Rail)
The horizontal members (of a double-hung window) which come together.

Circle Top Transom
See Fanlight.

Clerestory – (also Clearstory – High-Light Window)
A window in the upper part of a lofty room that admits light to the center of the room.

Coated Glass
A window glass with an outside surface provided with a mirror reflective surface; the shading coefficient ranges from 20% to 45%. See Shading Coefficient .

Colonial
An architectural style associated with an early American period; Early American style c. 1730.

Colonial Windows
Windows with small rectangular panes, or divided lites, designated as 12-lite, 16-lite, etc.

Combination Window Unit – (Combination Storm Sash and Screen)
A window assembly containing a half screen and two glass storm panel; in frame, exposing the screen panel.

Commercial Standard
A voluntary set of rules and regulations covering quality of product (or installation), method of testing, rating of the product, certification, and labeling of manufactured products.

Condensation
The deposit of water vapor from the air on any cold surface whose temperature is below the dew point, such as a window glass or frame that is exposed to cold outdoor air. See Dew Point Temperature.

Convection
See Natural Convection and Forced Convection. A heat transfer process resulting from the circulation or movement of fluids, such as air.

Cove Molding
Trim molding with a concave face.

Crack Perimeter
The total length of the crack around a sash through which outdoor air could leak into the room. In a double-hung window, the total crackage is 3 times the width plus 2 times the height of the sash.

Dado
A rectangular slot or groove (with 3 surfaces) cut across the grain of a wood member, into which another board is fitted. See also Plough.

Degree-Day
A measure of heating demand, based on the difference between the mean daily outdoor temperature and 65°F. Cumulative totals for the month or heating season are used by engineers for estimating heating energy requirements.

Design Heat Loss
The calculated values, expressed in units of Btu per hour (abbreviated Btuh), for the heat transmitted from a warm interior to a cold outdoor condition, under some prescribed extreme weather conditions. The values are useful for selecting heating equipment and for estimating seasonal energy requirements. Infiltration heat loss is a part of the design heat loss.

Desiccant
A drying agent, such as silica gel, used by some manufacturers between the panes of insulating glass to prevent fogging between the panes.

Dew Point Temperature
The temperature of the air at which the water vapor in the air starts to condense in the form of liquid or as frost.

Double-Hung Window
Window with two vertically moving sashes, each closing a different part of the window.

Double-Strength Glass
Sheet glass with a thickness between 0.115” to 0.133” (3 to 3.38mm).

Double Windows – (Double Glazing)
Two windows, such as a regular window plus a storm sash; also an insulating window with air space between panes.

Double Window
Two windows separated by a mullion, forming a unit. Also called a coupled window.

Drip Cap
A horizontal molding to divert water from the top casing so that the water drips beyond the outside of the frame.

Dry Glazing
A form of glazing in which the glass is secured in the frame with a dry gasket, wood stops, or metal stops, instead of by a glazing compound. See also Reglet.

Emergency Exit Window – (Egress Window)
Fire escape window; large enough for a person to climb out; each bedroom should be provided with exit windows.

Extension Jamb – (Jamb Lining) – (Jamb Extender)
A board used to increase the depth of the jambs of a window frame to fit a wall of any given thickness.

Exterior Casing
See Casing.

Fasteners
Devices for jointing two parts together, such as screws nails and bolts.

Fenestration
The placement of window openings in a building wall; one of the important elements in controlling the exterior appearance of a building.

Finish Casing – (Finish Trim)
Interior trim boards around a window unit.

Fire-Escape Window – (Emergency Exit Window)
Window which opens onto fire escape; window designed for emergency exit.

Fixed Light – (Fixed Sash)
Window which is non-operative (does not open).

Flashing
Sheet metal provided for drainage of water and to prevent water penetration into building.

Flat Glass – (Window Glass) – (Plate Glass) – (Float Glass) – (Rolled Glass) – (Cylinder Glass)
Glass sold in flat sheets and named according to the method used in its manufacture.

Float Glass
Smooth glass formed on the top of molten tin surface; a flat glass sheet.

Frame
See Window Frame.

French Window
Two casement sash hinged on the sides to open in the middle; the sash extends to the floor and serves as a door to a porch or terrace.

Forced Convection
A heat transfer process, aided by mechanical circulation of a liquid (such as water) or a gas (such as air). This applies to natural wind flow over a window.

Glass
An elastic transparent material composed of silica (sand), soda (sodium carbonate), and lime (calcium carbonate) with small quantities of aluminum, boric, or magnesia oxides. See Flat Glass.

Glazing
The installation of glass in a window opening; also the fenestration or windows.

Glazing Bead – (Glass Stop) – (Wood Stop) – (Sill Bead)
A removable trim that holds the glass in place.

Glazing Channel
A groove cut into the sash for the mounting of glass.

Glazing Rabbet
See Rabbet.

Grilles
See Muntin .

Groove
A long, narrow cut on the face of a wood member; a groove across the grain is a Dado; one parallel with the grain is a Plough. A groove exposes three surfaces, in contrast with the two surfaces exposed in a Rabbet or Notching. See Rabbetted Joint and Plough.

Hanging
Mounting a sash in its frame.

Hanging Sash – (Hung Sash)
Sash hung on a cord connected to a counterweight.

Head
The top or upper member of any element or structure; in windows, it refers to the top of the frame, as in Round Head Window. See Head Jamb.

Head Jamb(Head)
All of the horizontal members at the top of the window frame.

Header – (Lintel) – (Beam)
Supporting member or beam above window opening which transfers building weight above to the supporting wall structure on each side of the window. The term header is generally in reference to a wood beam, whereas Lintel often refers to a steel beam.

Head Rail - See Rail.

Heat-Absorbing Glass – (Tinted Glass)Heat-Absorbing Glass
Window glass containing chemicals (with gray, bronze, or blue-green tint) which absorb light and heat radiation, and reduce glare and brightness. Shading coefficient of this glass varies from about 50% to 70%.

Heat Transfer Coefficient – (U-value)
A value indicating the rate of heat flow through a building construction, expressed in units of 'Btuh per square foot of surface per degree F. difference between indoor and outdoor air temperature.' This is numerically equal to the 'inverse of the sum of R-values' for the construction.

Hinge
A movable joint enabling a window to swing open.

Hopper Light – (Hopper Vent) - (Hopper Ventilator)
Inward opening sash hinged at the bottom.

Horizontal Sliding Window
(Horizontal Slider) Windows which slide horizontally.

Hung Sash
See Hanging Sash.

Hung Window
Window with one or more hanging sashes.

Hygroscopic
The ability to 'give off' and 'take on' moisture, as in wood exposed to changes in relative humidity of air.

Insect Screen – (Window Screen) - (Screen)
Woven mesh of metal, plastic, or fiberglass stretched over a window opening to permit air to pass through, but not insects.

Inside Casing
(Interior Casing) - (Interior Finish) -(Interior Trim) - The inside visible molding surrounding the interior of the window frame, See Casing.

Inside Trim
See Inside Casing.

Inside Sill
See Stool .

Insulating Glass
Double- or triple-glazing with an enclosed, dehydrated, and hermetically sealed air space between the panes; the space is commonly from 3/16" to ¾".

Insulated Window
A window with multiple glazing that provides one or more air spaces between layers of glazing.

Interior Finish
See Inside Casing.

Interior Glazes
Glazing installed from inside of building.

Interior Mullion Casing
The inside trim between adjacent windows. See Mullion.

Jal Awning – (Awning Window)
Window with several out-swinging, awning-type windows that pivot near the top of the glass and operate in unison.

Jamb
A vertical member at the side of the window frame; also refers to the horizontal member at the top of the window frame, as in Head Jamb and Window Jamb.

Jamb
All of the vertical members at the side of the window frame.

Jamb Depth
Width of the window frame from inside to outside.

Jamb Extender
See Extension Jamb.

Knocked-Down
Not assembled; parts for a window frame pre-manufactured for assembly at a later
Laminated Glass – See Shatter-Proof Glass.

Latch – (Catch) – (Lock)
A device which holds a window shut, such as the latch at the meeting rail of a double-hung window or one mounted on the stile of casement windows, often referred to as a lock.

Lead Light – (Lead Glazing) – (Stained Glass)
Window with small panes of glass set in grooved rods of cast lead (or came). The glass can be clear, color, or stained.

Light – (Lite)
A window; a pane of glass within a window. Double-hung windows are designated by the number of lights in upper and lower sash, as in six-over-six.

Lintel
Horizontal member (wood, steel, or stone) over a window opening to support the weight of the wall above (See also Header).

Lock
A fastening device in which a bolt is secured and can be operated by a key. Commonly used to refer to Latches or Catches.

Lock Rail
See Meeting Rail.

Lock Stile
The vertical member (stile) of a casement sash which closes against the surrounding frame.

Low-Emissivity Coating (Low-E)
Coating for glass surfaces which reflects radiant heat energy rather than allowing that energy to radiate through the glass surface. The lower the emissivity of the glass the lower the heat transfer coefficient.

Lunette
A crescent-shaped window framed by moldings or an arch.

Meeting Rail – (Lock Rail)
One of the two horizontal members of a double-hung sash which come together See Check Rail.

Member
Any structural part of a window, such as a rail, stile, or lintel.

Millwork
Window sash and other wood products made in a wood-working plant.

Miter Joint
Two members joined at an angle, commonly 45 degrees.

Moisture Barrier – (Vapor Barrier)
A material which retards the passage of water vapor from one space to another. Polyethylene sheet is commonly used as a vapor retarder.

Moisture Content
Percentage of dry weight of material which is composed of water, such as in wood.

Mold – (Molding)
A relatively narrow strip of wood used to conceal a joint or to emphasize ornamentation of a structure.

Mould – (Moulding)
British spelling of mold, and molding.

Mullion
Vertical member between window units.

Muntin – (Sash Bar) – (Window Bar) – (Glazing Bar)
a secondary framing member (horizontal, vertical, or slanted) to hold the window panes in the sash. This term is often confused with Mullion.

Muntin Grilles
Wood, plastic, or metal grilles.

Multi-Lite Sash
A sash divided into many lites.

Mylar
Trade name for a clear, durable plastic sheet used for covering an inside storm panel or for removable, roll-up glazing over an entire window frame.

Natural Convection
A heat transfer process involving motion in a fluid (such as air) caused by difference in density of the fluid and the action of gravity This is an important part of heat transfer from the glass surface to room air. See Forced Convection.

Notching
A rectangular cut across the grain of the wood member at the end of the board (See Rabbet).

Obscure Glass
(Visionproof Glass) - Any textured glass (frosted, etched, fluted, ground, etc.) used for privacy, light diffusion, or decorative effects.

Operator
Crank-operated device for opening and closing casement or jalousie windows.

Oriel Window
A window projecting from the wall and carried on brackets, corbels, or a cantilever. Unlike a Bay Window, the projection of an Oriel does not extend all the way to the ground.

Orientation
The placement of a room, window, or building with respect to sun, wind, earth, access, or view (See also Solar Orientation).

Outside Casing
(Outside Facing) - (Outside Trim) - (Exterior Casing) - That portion of the window frame which is exposed to the outdoors, See Casing.

Outside Glazing
Glazing installed from the outside.

Pane
A sheet of glass for glazing a window. After installation, the pane is referred to as a 'light' (lite) or 'window light.'

Parting Bead – (Parting Strip) – (Parting Stop)
A vertical strip on each jamb that separates the sashes of a double-hung window.

Patterned Glass
One or both surfaces of glass with a rolled design; used for privacy and light diffusion.

Percentage Humidity
Weight of water vapor in air divided by weight of vapor contained in saturated air, expressed as a percentage.

Picture Window
Large fixed windows; introduced in the 1940s.

Plastics
Artificial substances made of organic polymers that can be extruded or molded into various shapes, some of which have been adapted to windows. The material is commonly stiffer than rubber.

Plough – (Plow)
A rectangular groove or slot (with 3 surfaces) cut parallel with the grain (See Dado).

Polyvinylchloride
See PVC.

Prime Sash
The balanced or moving sash of a window unit.

Prime Window
Window with single or multiple glazing to which storm sash may be installed.

Projected Window
An awning-type window that swings either inwards or outwards at the top or the bottom. The 'PIB' or 'project in at bottom' window can be cleaned from the inside.

Psychrometric Chart
A chart which shows dry bulb and wet bulb temperatures used to determine the relative humidity of air and the dew point temperature. Other engineering data referring to moisture in air are also shown.

PVC
(Polyvinylchloride) - An extruded or molded plastic material used for window framing and as a thermal barrier for aluminum windows.

Radiation
The transmission of energy through space without heating the air between, as in Solar Radiation.

Rabbet
A rectangular notch (consisting of two surfaces) cut parallel with the grain of wood along the edge. See Notching.

Rabbetted Joint
The joint formed by two boards with rabbetted ends, as in some window frames.

Rail – (Head Rail) – (Top Rail) – (Bottom Rail) – (Meeting Rail)
Horizontal member of a window sash.

Reflective Glass
Window glass coated to reflect radiation striking the surface of the glass.

Reglet
A plastic or wood molding placed in a concrete or masonry opening to provide a uniform groove for a spline-type gasket to hold window glass. See Dry Glazing.

Relative Humidity
Weight of water vapor in air divided by the weight of water vapor in completely saturated air at the same temperature, expressed as a percentage.

R-Value – (Thermal Resistance)
A measure of resistance to heat flow of a material or construction; a higher value indicates a better heat insulating property. The R-value of an ordinary single-pane sash with a 15 mph wind on one side is about 0.9.

Safety Glass
A strengthened or reinforced glass that is less subject to breakage or splintering, such as glass for storm doors and some windows. See Tempered Glass, Shatterproof Glass, and Plexiglas.

Sash - (Window Sash)
Framework of stiles and rails in which the lights of a window are set.

Sash and Frame
A window and its casing frame.

Sash Balance
A device for counter-balancing a sash of a double-hung window to hold it in the up position.

Sash Stop
A molding that covers the joint between window sash and the jamb.

Screen
See Insect Screen.

Screen – (Wire Cloth)
A close-mesh woven screening material of metal, plastic, or fiberglass for a window screen, to block the entry of insects but permit light, air, and vision through the screen.

Sealant
A compressible plastic material used to seal any opening or junction of two parts, such as between the glass and a metal sash, commonly made of silicone, butyl tape, or polysulfide.

Sealed Double Glass
Two panes separated by a sealed space. See also Insulating Glass.

Shade Screen – (Sun Screen)
A specially fabricated window screen of sheet material with small narrow louvers formed in place to intercept solar radiation striking a window; the louvers are so small that only extremely small insects can pass through. Also, an awning with fixed louvers of metal or wood construction.

Shading Coefficient
A decimal value which is the solar gain of a window, divided by the solar gain for a clear single-glass window of the same size. The shading coefficient of clear, double-glazing is about 0.85 to 0.9.

Shatter-Proof Glass – (Laminated Glass)
Two sheets of glass with a transparent plastic sheet sandwiched between to form a pane resistant to shattering.

Side Light – (Margin Light)
A fixed, often narrow, glass window next to a door opening (or window).

Silicone – (Silicone Sealer)
An enduring sealing agent that resists water. See Sealant.

Sill – (Sill Plate) – (Inside Sill) – (Outside Sill)
The horizontal members at the bottom of the window frame; a masonry sill or sub-sill can be below the sill of the window unit.

Single-Hung Window
A window that is similar to a double-hung window except that the top sash is stationary.

Single-Strength Glass
Glass with thickness between 0.085 to 0.100" (2.16 mm to 2.57 mm).

Sliding Sash – (Sliding Windows)
A window which moves horizontally in grooves or tracks.

Sling Psychrometer
A measuring instrument with two thermometers (dry-bulb and wet-bulb) used for determining the dewpoint and relative humidity of air; its relation to windows is ascertaining the point at which moisture will condense on the inside surface of the glass. See Psychrometric Chart.

Solar Heat Gain
Heat from solar radiation that enters a building.

Solar Orientation
A building placed on a lot so that the long dimension faces south and a majority of the windows are south-facing.

Sound-Insulating Glass – (Sound-Resistive Glass)
Double glass fixed on resilient mountings and separated so as to reduce sound transmission.

Sound-Resistive Glass
See Sound-lnsulating Glass.

Spacer
The linear object that separates and maintains the space between the glass surfaces of insulating glass.

Spiral Balance
See Sash Balance.

Spline
A rectangular strip of wood or metal inserted between two boards, which have been slotted to receive it.

Spring Bolt
A fastener for holding the sash in a fixed location by means of a spring-loaded bolt in the stile entering a hole in the jamb.

Stacked Window Units
A combined grouping of awning, hopper, casement, or non-operative windows to form a large glazed unit.

Stained Glass Window
A window with a painted scene or pattern that has been fired into the glass. Windows with plain colored glass set in lead are also called stained glass. See Lead Light.

Stationary Sash
A fixed sash; also referred to as a picture, studio, vista, or view sash.

Stile
The vertical-edge members of a window sash.

Stool
A shelf-like board of the interior part of the window sill, against which the bottom rail of the sash closes.

Stop – (Bead, Side Stop, Window Stop, Parting Stop)
The molding on the inside of the window frame against which the window sash closes, or in the case of a double-hung window, the sash slides against the stop.

Storm Sash – (Storm Window)
An extra window on the outside to protect an existing window, but mainly to increase the thermal resistance of the window.

Sunburst Light
See Fan Light.

Sun Screen
See Shade Screen.

Sweep Lock
A sash fastener located at the meeting rails of a double-hung window, which rotates and clamps the two rails closer together.

Tape Balance
See Sash Balance.

Tempered Glass
Special heat-treated, high-strength safety glass which shatters into pebble-sized particles but not into slivers.

Therm
In technical usage, the term is a convenient measure of heating value, namely 100,000 Btu. One therm is roughly equivalent to the heating value of 100 cubic feet of natural (methane) gas.

Thermal Barrier
(Thermal Break) - A material of high thermal resistance placed between two metal sash, or installed between adjoining metal framing of metal windows, in order to reduce thermal conduction from indoors to outdoors.

Thermal Conduction
Heat transfer through a material by contact of one molecule to the next. Heat flows from a high temperature area to one of lower temperature.

Thermal Conductivity
Heat transfer property of materials expressed in units of 'Btu per hour per inch of thickness per square foot of surface per one degree F. temperature difference.' Referred to by the letter 'k.'

Thermal Conductance
Same as Thermal Conductivity except thickness is 'as stated' rather than one inch. Referred to by the letter 'C.'

Thermal Insulation
A material that resists heat flow. Material having a high R-value.

Thermal Resistance – (R-value)
A property of a substance or construction which retards the flow of heat; one measure of this property is R-value. See Heat Transfer Coefficient.

Tinted Glass
See Heat-Absorbing Glass.

Top Rail
See Rail .

Transom
(Transom Bar) - A horizontal member separating a door from a window panel above the door, or separating one window above another.

Transom Light
(Transom Window) - The window sash located above a door.

Trim
Visible molding surrounding a window opening. See Casing.

Triple Glazing
Three panes of glass with two air spaces between, commonly consisting of an insulating glass with a separate storm sash. Also available as an Insulating Window in a single frame.

Triple Window
A term generally referring to any tripartite group of windows with square heads. These are frequently found on Colonial Revival houses; they suggest Palladian Windows but are less expensive to build.

Ultra-violet Radiation
Extremely short wave length invisible radiation, which is a component of solar radiation, and merges into the visible spectrum; attributed as a source of skin sunburn and color fading of draperies and carpeting.

U-value
A value indicating the rate of heat flow through a building construction, expressed in units of 'Btuh per square foot of surface per degree F. difference between indoor and outdoor air temperature.' This is numerically equal to the 'inverse of the sum of R-values' for the construction. Also see Heat Transfer Coefficient.

Vapor Barrier – (Vapor Retarder)
A membrane or coating which resists passage of water vapor from a region of high vapor pressure to low pressure, more accurately called a Vapor Retarder.

Vertical Sliding Window
One or more sashes that move in a vertical direction.

Vinyl
See PVC.

Visible Spectrum
That portion of the total radiation that is visible to the human eye and which lies between the ultra-violet and the infra-red portions of the electromagnetic spectrum. The colors associated with the visible spectrum range from violet, indigo, blue, green, yellow, orange, through red.

Weatherstrip
A strip of resilient material for covering the joint between the window sash and frame in order to reduce air leaks and prevent water from entering the structure.

Weathertight
Sealed to prevent entry of air and precipitation into the structure.

Weephole
Small holes drilled along the bottom edge of storm sash or combination storm-screens to permit moisture condensation or wind-driven rain to drain away from the sill to the outdoors.

Window
A glazed opening in an external wall; an entire unit consisting of a frame, sash and glazing, and any operable elements.

Window Bar
See Muntin.

Window Frame
The fixed frame of a window, which holds the sash or casement as well as hardware.

Window Hardware
Various devices and mechanisms for the window including: catches, cords and chains, fasteners and locks, hinges and pivots, lifts and pulls, pulleys and sash weights, sash balances, and stays.

Window Unit
A complete window with sash and frame.

Glossary of Terms

Trim and Mouldings Terms:

BASIC PROFILES AND USES(Courtesy Wood Moulding & Millwork Producers)

Pipe and Fittings Terms:

Window & Door Terms:

BASIC PROFILES AND USES
(Courtesy Wood Moulding & Millwork Producers)