Home / Product Support / Glossary

Product Support


Trying to make sense out of all of the technical information? We can help. We’ve taken all of the terms you need to know regarding polyurethane and PVC millwork and compiled them into this easy-to-use glossary.

Click here to print.

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

A piece of decorative millwork that complements an acorn pediment and looks similar to what the name implies, an acorn. Comes in half round and full round styles.

Substance capable of holding material together by surface attachment; it is a general term and includes many adhesives inclusive of "glue." (See PL Premium Adhesive).

Highly detailed ornamentation that can accent a wall or ceiling application. Looks like sculpted plaster.

Arch End Cap
A divider or spline accent that separates the arch mould and the straight linear moulding.

Arch Moulding
Preformed half round arch that surrounds half round windows, half round sunburst or half round spoked pediments. Flat arch moulding consists of a flat profile. Decorative arch moulding consists of a shaped profile. All arches have a full complement of straight linear mouldings to match.

Arch Pilaster (See Pilaster)
Profile matches profile of arches available. Use in conjunction with arch as a vertical door/window casing.

Art Deco
Style of decorative art of 1920's and 1930's marked by use of geometric designs and bright colors.

Rounded profile ornaments used primarily for capping posts. (Also urns, acorns, pineapples).

Baluster (Spindle)
Vertical member used to fill an open area between railing and floor or tread, helping to support the railing.

A barrier system which includes handrails, newels and balusters.

Barrier Coat
First coat of protective paint surface that acts as a mould release and also forms the moulded-in protective skin of the finished polyurethane product. The barrier coat also prepares the polyurethane foam part to accept a paint finish.

Moulding applied around the perimeter of a room at the point of intersection of the wall and finish floor; base shoe is generally used with it, forming a two member base; (also baseboard, mopboard or skirting).

Semicircular or rounded profile; also a small moulding to secure glass or panels to doors, hence "glass bead."

Bead and Cove
Combination of a bead and a cove profile.

Bondo (Brand Name)
Automotive type filler putty used to patch and cover countersunk fastener holes, seams and damaged polyurethane foam products. Tends to work better than wood filler putty due to the elastic properties of the Bondo material.

Bottom Trim (BT)
Trim moulding accessory that can be added to the bottom of a door or window crosshead to create a taller crosshead with more detail.

Primarily decorative exterior uses include porches, cornices, and part of gable end decoration. Interior applications support or hide joint between beam and wall, embellishments for doorways, supports for shelving, and hanging objects.

Lower flat area of a door or window crosshead. Part number refers to the breastboard dimension width when selecting a particular header size.

Breastboard Dimension
Measurement in inches of the breastboard width. Part number of door/window crossheads refers to this dimension width.

Moulding of window and exterior door frames that abuts the exterior facing material of the structure; serves as the boundary moulding for brick or other siding material.

Butt Joint
A butt joint in millwork is where the cut edge is perpendicular to the length of moulding and two mouldings are glued together at this cut.

Upper member of an entrance, wainscot, partition or pilaster; (also cap trim, wainscot cap, dado moulding, chair rail cap); top portion, above the fluted area, of a pilaster; (also capital).

Cast Moulding
Manufacturing process by which a product can be duplicated many times over from an original master.

Compound for filling joints to prevent leakage of water and air. Weatherproof caulking is made of a silicone base.

Ceiling Medallion
Plaster like ornamental round ceiling accent, sometimes used as a trim collar for ceiling fans or hanging lights. Can be used in a sequence to create interesting ceiling and wall designs.

Chair Rail
Part of a family of mouldings used to define the lower section of the wall, and to protect the wall from scraping furniture. When used in conjunction with paneling or wainscoting the rail serves as an ornamental cap.

Celuka Process
Manufacturing process of PVC foam extrusion. The mixed PVC is extruded into two streams of PVC foam. They are then forced together, formed and cooled. This process suppresses cell formation at the surface resulting in a tough outer skin and a nonuniform inner cell structure.

Celuka Process
Manufacturing process of PVC foam extrusion. The mixed PVC is extruded into two streams of PVC foam. They are then forced together, formed and cooled. This process suppresses cell formation at the surface resulting in a tough outer skin and a nonuniform inner cell structure.

Closed Cell Structure
Like a bubble - it neither absorbs nor retains water (Polyurethane and PVC). Closed cell is what gives structural integrity to PVC, preventing water absorption, penetration and retention.

Supporting or decorative pillar used in building.

Combination Unit
Various styles of pediment and crosshead combinations available moulded as one piece for faster installation. Combination units have a slightly smaller projection dimension than a two piece pediment assembly.

A complex material, such as wood or fiberglass, in which two or more distinct, structurally complementary substances combine to produce structural or functional properties not present in any individual component. Composite trim combines wood fibers with a plastic or resin binder.

Compressed Fiber Trim
Engineered wood trim; mostly wood fiber board with resin added in, then heated and compressed into boards. The resin makes the boards moisture resistant for exterior use.

A particularly massive bracket.

Corner Strip Moulding
Mouldings to be used together to make an adjustable outside
corner - maximum 45°. Ideal to trim bay or bow windows.

Cornice (Cornice Mouldings)
Prominent horizontal projection moulding that crowns the wall of a building. Moulding such as crown, bead and cove applied to cornice construction.

Area where a fastener is recessed below the surface of the millwork.

Cove Moulding
Moulding with a concave profile used primarily where two members meet at a right angle; a rounded inside corner; opposite to a bullnose; (also scotia, cavetto, ceiling cornice).

Decorative form that resembles a lintel used to top a door or window, consisting of a breastboard with crown moulding surrounding the top portion, and moulded together as one piece. Crossheads come in heights from 6" to 18". A variety of accessories can be added to complement the design of a simple crosshead. (Also see Door Crosshead and Window Crosshead).

Crown Moulding
Moulding used on cornice or wherever an interior angle is to be covered. A sprung moulding used where two surfaces meet at an angle; usually applied wherever a larger angle is to be covered; (also cornice moulding).

Custom Design Product
Product involving the creation of original patterns and development time. Will be quoted on an individual project basis.

Weight of a substance per unit volume and measured in pounds per cubic foot. Polyurethane foams can vary for different applications. Fypon building products are at approximately 14 pounds/cubic foot.

Dentil Block
Smaller rectangle block which can be spaced closely together in a series or in sequence with moulding.

Dentil Moulding
Series of small square blocks uniformly spaced and projecting like teeth as used in cornice, front entrances and crossheads.

Divider Moulding Block
A spline accent block that is placed at the seam of a moulding run. Can also cap the end of a moulding run.

Door Casings/Window Casings
To case in a door or window is to enclose it with a moulding or series of mouldings. They are termed casings and included in the repertoire of most millwork suppliers. Casings range from simple beaded boards to highly complex series of profiles. In addition to mouldings, window or door casing might include such elements as corner blocks, a keystone, and base blocks. (See arches, door heads, pilasters, door/window moulding).

Door/Window Moulding
Trim moulding used as part of door or window casing. Often used in conjunction with door or window crosshead and rosettes.

Permanence or resistance to deterioration.

Overhanging lower edge of a roof. The margin or lower part of a roof projecting over the wall.

Eave Vent. A soffit ventilation system which serves a dual purpose combining the attractiveness of a moulding profile and the function of attic ventilation. Installs as one unit.

E-Vent Corner (Inside, Outside)
Accurate 45° premitered, preassembled corners that match up to straight linear E-Vent mouldings.

E-Vent Filler Block
Preformed filler block used to give additional support to the E-Vent moulding.

E-Vent Joining Block/End Cap
Used as a divider spline between linear moulding joints. Protrudes 1/4" from trim profile. Can also cap the end of a linear moulding run.

Egg and Dart
Moulding design using an egg and dart alternately. The egg is said to represent life, and the dart death.

Shaped like an ellipse (which is a closed plane curve that is oval in shape)

Expansion and Contraction
How moldings and materials will expand or contract based on temperature it is exposed to. For instance, polyurethane tends to expand or contact 1/4” for every 10’ length.

To construct by combining or assembling standardized parts into a custom size or design. For PVC trim, it is creating unique pieces from board or sheet stock.

A flat horizontal band or member between moldings, especially in a classical entablature.

Fascia Moulding
Trim moulding applied to fascia board (horizontal facing board just below edge of roof line). A flat board, band, or face, used sometimes by itself, but usually in combination with mouldings, often located at outer face of cornice.

Ornament at the top of a gable or spire, or at the end of certain structures. (See Balls).

Scalloped overlapping shingle style of ornamentation used as facade or gable decoration in late-Victorian and Colonial houses.

Application in which circle top window is placed along the side (flanked with) straight glass windows on each side. The circle top is covered with an arch and the side straight glass windows are flanked with crossheads.

Flat Trim
Moulding that has no decorative profile moulded in.

One of the long, parallel, rounded, decorative grooves on the shaft of a pilaster.

Free-Foam Process
Manufacturing process of free foam extrusion. The PVC is mixed and extruded in one unified piece. It is moved through a die and allowed to cool unaided. This process creates a uniform cell structure from core to surface.

Frieze Board
A decorative, often sculptured, horizontal band along the upper part of a building or a wall in a room. In house construction, a horizontal member connecting the top of the siding with the soffit of the cornice.

Gable Pediment
Decorative millwork used to cover the joint between the gable end of a house and its roof, or simply, gable end ornaments. Take the place of cornice mouldings on exterior of many early-to-mid-Victorian houses.

Lavish or superfluous ornamentation especially in architecture.

Glazing and Filler Putty
An automotive type filler used to fill small imperfections. Used to fill in and smooth the raw edges of the foam.

Gothic Arch
Form of pointed arch over doorway or window from architectural style prevalent in Western Europe from 12th through 15th centuries.

Heat Bending Kit
Kit system that utilizes heat blankets to heat up boards of PVC trim. The PVC then can be formed to a specific shape (arched trim pieces).

Heat Build-Up
When temperatures rise in a given area because there is not sufficient air movement. An example of this is how heat rises to the attic. If the attic is not properly ventilated, the heat will radiate back into the home. Heat build up can also occur between a storm door and entrance door.

Hybrid Product
A Fypon product that uses two types of materials that are synthetic and have the similar benefits.

Inside Moulding Block
(See Moulding Block).

Accessory available through siding manufacturers for installing trim work. J-channels are butt up against the trim work allowing the siding to be cut and fit into these channels.

J-Channel, Flexible
Used as J-channel; however, the liner is flexible to follow curved shapes.

Top and two sides of a door or window frame which contact the door or sash; top jamb and side jambs.

Jamb Extension (Sub-Jamb)
Jamb like member, usually surfaced four sides, which increases or extends the width of door frame jamb. Sub-jambs imply a larger width than "jamb liners", Can be used with window units. (Also extension jamb).

Jamb Liner
Small strip of wood, either surfaced four sides or tongued on one edge, which, when applied to the inside edge of a window jamb, increases its width.

Jamb Reveal (Face of Jamb)
The exposed surface of a jamb next to the door or window. The margin visible between the window or door jamb and the surrounding trim or casing.

Traditionally topmost member of an arch. Most often appears as part of an entryway surround or window crosshead. Available in three styles including plain, recessed panel, and art deco.

To glue flat sheets of PVC together to create the thickness necessary to fabricate parts from.

A building component installed into the side wall to allow ventilation and/or decoration on a building. Styles may be square, rectangle, triangle, quarter or half round, etc. A non-ventilation louver that is to be used as a decorative building accent is known as a decorative louver. A louver with open slats to allow ventilation into the attic area is known as a functional louver. (See catalog for all styles of louvers)

Louver Trim
One piece moulded trim that surrounds various shapes of a louver giving the louver the appearance of a more massive building component.

Percentage rating of how well a product/material absorbs light. The higher the LRV percentage, the greater amount of light the material/color reflects (light carries heat). The lower the LRV, the more the material/color will heat up from light absorption.

An original from which copies can be made.

Moulded Edge
Edge of piece machined to any profile other than square or eased edge.

Ornamental strip used to decorate a surface, often used to accent or emphasize the ornamentation of a structure and to conceal surface or angle joints.

Moulding Block (Inside, Outside)
A moulded corner system that eliminates the need for difficult angled cuts. Lineal mouldings easily butt up to these preformed corners.

Term used to join two or more windows at the jamb or door side lights to the door unit. Fypon manufactures fluted mull mouldings to cover the seams where the jambs meet.

A wall recess traditionally used to display a sculpture or ornamental object.

Nonpenetrating Stain
A type of stain formulated to lay on top, and not soak into the open pores, of a surface.

Order Acknowledgment
Upon our customer service staff receiving an order via FAX or phone call, Fypon will FAX or phone a confirmation back to our customer that the order has been received, and verify the products ordered.

Useful designation for all those infrequently used, highly decorative wall and ceiling motifs, such as garlands, leaves, scrolls, shells, shields, sunburst, and wreath embellishments. Ball ornaments include urns, acorns, pineapples, etc.

Outside Moulding Block
(See Moulding Block).

Used to describe topmost member of a formal entryway (Pediment stacks above the crosshead) and includes the caps or heads which ornament windows and interior door. Varieties include: Acorn, broken, peaked, rams head, rounded and solid.

Vertical column, often ornamental, that projects slightly from the wall. Most are purely decorative. May be rectangle or half round; often has a base (plinth block), shaft (middle section), and capital. Most often used as simulated columns in entryway and other door openings.

Incline slope of a roof or the ratio of the total rise to the total width of a house. Roof slope is expressed in the inches of rise per foot of run.

Pitch Block
Thick, massive filler block that can be field trimmed to adjust to various roof pitches.

PL Premium Adhesive
Polyurethane base construction adhesive that is superior for attaching and joining polyurethane millwork.

Plastic Wood Filler
(See Bondo, and Glazing and Filler Putty).

Plinth Block
Square block at the base of a pilaster; thicker and wider than the abutting members.

Polyurethane Foam
Mixture of two resins that create a chemical foaming reaction.
Polyurethane foam (or polyurethane) is the component of Fypon products. Once cast and removed from the mould it is difficult to differentiate from wood or plaster components. Characteristics of the finished product include resistance to rotting, splitting, warping, paint peeling, chipping, and insects.

Prime Coat Finish (Primer)
A paint finish intended for a later application of paint. The first coat of paint in an application that consists of two or more coats.

Thrust outward, protrude. The distance the millwork protrudes away from a surface.

Polyvinyl Chloride

Quarter Round Louver
(See Louver). Available in left and right hand configuration.

Decoration forming an exterior outside corner (stone look) to a building.

Horizontal bar supported at both ends or at intervals by posts, as in a balustrade, and used as a barrier.

A square block with a circular decorative design in the center usually used as a corner block as part of the casing around windows and doors.

Routed Edge
The corner of the millwork has been removed to give the piece a finished look.

RTV Silicone Mould
The production mould from which the actual polyurethane building products are moulded or cast.

One of a series of curves shaped like semicircles that form a border.

Scarf Joint
The joint where the linear moulding is cut at an angle, usually 45 degrees, and paired with another moulding cut the same. This provides a larger surface area for the glue to hold.

A decorative wall bracket for candles or electric lights.

Shoe Moulding
Quarter round trim applied at the bottom of baseboard where it meets the floor.

Sill Moulding
Moulding designed to resist or shed water away from a wall surface.

Usually the underside of an overhanging cornice.

Decorative type of spindle system that covers the distance between columns and posts.

Special Made Fabrication Product
Product taken from stock as shown in catalog then cut, seamed and assembled to custom size or design as requested by the customer.

Standard Millwork
All product shown in the catalog.

A semielliptical area, the lower center of which contains a sun-like figure with fanned sun rays radiating therefrom.

The material has a definite melting range usually associated with the base resin. Thermoplastics can warp if put in an area where heat build-up can occur (materials include polystyrene, PVC, polyethylene and polypropylene).

A material that does not normally exhibit a definite melting range. They are not likely to warp if placed where heat build-up can occur (material includes Polyurethane).

The finish materials in a building, such as mouldings, applied around openings (window trim, door trim) or at the floor and ceiling of rooms (baseboard, cornice, and
other mouldings).

Trim Strip (T)
A decorative accessory that can be added to create a more detailed crosshead.

Undersill Trim
Accessory available through siding manufacturers for installing trim work. Undersill trim is a thinner type of J-Channel that allows the siding to be cut and fit into the undersill channel.

A consistent core cell structure that lends itself to fabrication.

Urethane Foam
(See Polyurethane Foam).

UV Stable
Ultraviolet sunlight stable. Sun rays will not affect the quality of the product.

Vent (Ventilation)
Provide with an opening for the circulation (or passage) of fresh air.

A lower interior wall surface that contrasts with the wall surface above it. An interior wall composed of two different interior wall surfaces, one above the other.

Window Panel
Decorative raised panel placed directly below a window. Other applications include placement in a series creating a wainscoting system, or around the front of a whirlpool tub to act as water resistant, decorating access panels.

Special moulded-in texture on the surface of polyurethane millwork resembling oak, redwood or cedar. Product will accept nonpenetrating stain or paint.

Wreath and Bow
Large decorative wreath shaped building accent usually placed on the gable end of a traditional building.