Carpentry Dictionary Terms 

Carpentry Terminology

Carpentry dictionary terms that most professional carpenters use in the carpentry trade. Extend your vocabulary with this abundant amount of information. That can and will have you sounding like the professionals and you will know what you are talking about.

Apron The piece of trim around the interior side of a window that sits below the window stool and sup­ports it.

Baseboard A piece of trim, either plain or milled. installed around a room at the base of the walls to con­ceal the joints of walls and adjoining floor covering.

Baseboard shoe A narrow piece of trim, usually quarter round. attached to the baseboard at the floor to hide any gaps.

Batten Any small strips of lumber used for bracing. fora rigid guideline, for furring, and for some plank panel walls. among many small jobs.

Batts Short lengths of insulation usually about 4 feet long, sold flat instead of in rolls. Batts are also available with and without paper foil backing.

Beam A horizontal structural mem­ber that sits on posts or walls and supports the platform or roof above it.

Bearing wall A wall that supports the floors or roof above it. Where there are floors above, the bearing wall often supports the ends of the joists overlapped to span the width of the structure. If a bearing wall is removed, its load-carrying function must be replaced by a beam.

Building code The rules and regula­tions governing the acceptable spec­ifications and building types allowed in a city or town. Local building per­mits are almost always required for new construction or major renova­tion.

Building paper Also called felt paper or tar paper used as a cushion or a moisture barrier between layers in a house. such as between a hardwood floor and the subfloor, or between exterior siding and sheathing.

Carpet stretcher A device that grips carpet and stretches it either with force applied by the knee (to a knee kicker, a small carpet stretcher) or mechanical force (in a larger power stretcher).

Casing The boards lining the inside of a doorway or window frame, or more broadly, the flat trim nailed around such openings.

Caulking A soft compound for seal­ing joints against leaks (of water. or air. or noise). It may be silicone, neo­prene. or one of a variety of other syn­thetic compounds.

Ceramic tile Fired clay tile that is hard and may be glazed or unglazed. 1 square inch or smaller to 1 square foot to larger in size, available in a profusion of colors, shapes. pat­terns. and textures.

Chair rail A piece of molding that runs around a room about 31/2 feet above the floor (approximately the height of a chair back). It evolved from wainscoting.

Cleats Structural members that hold larger parts in place.

Collar beam Beams between rafters that tie them together and support the roof: also beams hung between rafters to support a ceiling.

Concrete A mixture of sand or gravel, Portland cement, and water that sets hard. Usually reinforced with wire mesh when poured for basement floors.

Corner bead A rigid metal corner attached to an outside wallboard or plaster corner to strengthen it and to provide a foundation for joint com­pound in finishing the corner.

Countersink Used with a countersink bit. to bore a beveled opening in a pilot hole that is wide enough to accommodate the head of a flathead screw slightly below the surface when fully driven.

Crawl space An unusable low space. above or below the house, just tall enough to permit such work as jack­ing up a sagging ground floor from below or installing ceiling fixtures from above.

Cripple stud The shortened stud above a doorway or window. It main­tains the structural integrity of the wall and provides a nailing surface for wall coverings.

Cross bridging Diagonal braces between joists that keep them from bending out of line. Single diagonal braces are called bridging; they may be wood or metal.

Darby A flat. wide board with a han­dle used for the first smoothing of concrete just after it has been poured. These can be rented.

Diffusion panel A translucent piece of plastic under a light fixture or sky­light that admits light, but masks what is above.

Double header A header double the thickness of the rafters or joists it is attached to. Used for long spans.

Filter mask A device to cover the nose and mouth to prevent the inha­lation of dust and dangerous parti­cles in the air.

Fish tape Flat, flexible metal tape used for pulling wiring through walls where there is no easy access behind the wall surface.

Flashing Strips of thin metal attached to a roof or at the junction of a roof with such structures as a chimney or a skylight, to prevent leaks.

Floorboard A board in a wood floor. Floorboards may be milled or not and are various lengths and widths.

Footing The concrete base support­ing foundations, chimneys, and such structural members as posts.

Framing The process of building a house, or walls within a house. from wood in the form of a framework to support wall, floor, and ceiling.

If you are a carpentry apprentice  you may hear these carpentry dictionary terms frequently in your career. Most of the terms I am familiar with and I use them frequently myself. Study them and take advantage of this wonderful opportunity. Good luck and continue to brush up your basic carpentry skills on this website.

Furring The process of leveling parts of a ceiling, wall, or floor by means of wood strips called furring strips. before adding the finish surface.

Glazier's points Small wedges of metal most commonly used to hold a pane of glass in a window frame; also used for various other small repairs.

Girder A main beam, usually running the length of a structure. that sup­ports the floor joists and is itself sup­ported by a post (or posts) in mid-span and at either end by the foundation.

Hardboard Sheet material com­posed of wood fibers compressed at high heat. The resulting material is quite hard.

Header A structural member, running at right angles to joists and rafters and connecting to the rest of the framework, at such openings as those for skylights, doorways, or stairways.

I.beam A steel beam that in cross section looks like a capital I. Used to span distances greater than wood beams can support.

Jack rafter A rafter shorter than full length, cut for the installation of a skylight, for example.

Jack stud A stud in a doorway or below a window, that does not reach the top plate.

Jamb The vertical inside face of a door or window opening.

Joint compound A thick. spreadable substance that dries hard and can be finished like plaster. It is used to fill the seams between sheets of wall­board and for small repairs to dam­aged plaster or wallboard walls.

Joist A horizontal structural member that supports a floor and a ceiling in the case of middle floors, and a ceil­ing alone in the case of a top floor. Joists are often tied together with cross bridging for extra rigidity.

Knee wall A wall built under a sloping roof that does not reach to the height of the ceiling.

Lath A strip of wood used as a foun­dation for plaster walls and ceilings. Laths are nailed close together but not touching. Plaster oozes through the cracks between laths to anchor the surface.

Masonry Any construction of bricks. concrete. or stone.

Molding Various types of wood used for decorative or practical trim. Mold­ing styles range from flat lath to ornately carved, grooved, or stamped picture-frame moldings. It is usually applied to conceal joints of dissimi­lar surfaces.

Nailer An extra piece of wood added to a framework to provide a nailing surface for all edges of something (usually a sheet of wallboard or pan­eling) to be attached.

On center A phrase designating the distance between the centers of regularly-spaced holes. or such parts as studs in a wall.

Particle board Inexpensive sheet material composed of wood chips, or particles, and adhesive pressed into sheets. Fairly brittle and not as easy to nail through as wood.

Partition A wall that divides space but plays no part in the structural integrity of a building.

Pilot hole A hole drilled to make it easier to drive screws into wood. Pilot holes are drilled slightly nar­rower than the diameter of the screw to be used.

Plaster A mixture of sand. lime, and water of a consistency that can be applied to a wall or ceiling with a trowel. Various plasters have differ­ent uses. such as for patching holes, or for finishing a smooth surface.

Plate A horizontal member. at the top or bottom of a wall, to which the studs are fixed: either top plate or bottom plate may be doubled.

Prehung door A door that is delivered from the factory already hung in its casing so that it need only be attached to the doorway.

Rafter A structural member that supports a pitched roof. serving for the roof sheathing the same purpose as joists for floors.

Riser The vertical facing of a step in a staircase where the steps have been closed in.

Roof sheathing The material, usually boards or sheets of plywood, attached to the top surface of the rafters as a foundation for such roof­ing material as shingles.

Roofing cement A synthetic or tar- based waterproof substance used to seal joints, cracks, or holes in a roof.

Row running cutter A knife for cut­ting carpeting that follows the rows of pile.

Saddle The strip under a door that joins the floors of two rooms by con­cealing the seam between them.

Sash The frame which holds the glass in a window. In either a case­ment window or one that slides up and down. the sash is the part that moves.

Screed Forms on stakes driven into the ground that serve as a guide for leveling a concrete floor.

Shims Thin wood wedges used for tightening the fit between pieces. as when they fill the gap between the top plate and joists in new wall con­struction. or for leveling strips of fur­ring over an uneven surface.

Shiplap A milling treatment for the edges of boards that results in one board overlapping the next along one edge when they are joined. Used often in plank paneling.

Sleepers Boards laid over a concrete floor as a foundation for the subfloor­ing of a new floor.

Spacer block A piece of lumber used between larger attached members to maintain a uniform separation (for instance, between two studs at the outside corner of a frame wall). Also called a filler block.

Stain Any of various forms of water-. latex-. or oil-based coloring agents. transparent or opaque. designed to penetrate the surface of wood.


Starter hole A hole drilled inside the outline of a shape to be cut out of a sheet of material (such as wallboard. to accommodate an electrical outlet) to permit inserting a saber saw. cop­ing saw, or keyhole saw blade to make the cut.

Stud Vertical member of a frame wall. usually placed at either end and one every 16 inches on center to facilitate covering with standard- width wallboard or paneling. May be 2x3. 2 x 4. 2x6 depending on the structural requirements of the wall.

Subfloor The floor surface below a finished floor. Usually made of sheet material like plywood. in older houses it is likely to consist of diago­nally attached boards.

Sump A hold dug in the lowest cor­ner of a basement to collect water from the floor so that it can be pumped away.

Tack cloth A piece of cheese cloth or other lint-free cloth treated with tur­pentine and a small amount of var­nish to produce a tacky surface that picks up and holds dust and lint.

Tackless strip A thin strip of wood or metal in which many small. sharp teeth are imbedded to grip the edges of a wall-to-wall carpet when they are hooked over the teeth. The strip is nailed down: it takes its name from the amount of tacking it eliminates from carpet installation.

Tongue and groove The milling treat­ment of the edges of a board result­ing in a protruding tongue on one side and groove the same size on the other. For the purpose of joining sev­eral boards.

Underlayment A smooth surface laid down to receive another surface, such as sheets of plywood under a ceramic tile floor.

Vapor barrier Either plastic sheeting or the sealed side of fiberglass insu­lation installed beneath a wall's sur­face as a waterproof barrier to keep moisture from within a room from condensing and causing rot inside walls or under the roof.

Wainscot Paneling that reaches from the floor to about one third the height of a wall, capped with molding.

Wallboard Also known as gypsum board. drywall, and plasterboard, a paper covered sandwich of gypsum plaster used as the primary wall cov­ering in almost all homes. It can be finished to look like a plaster wall. or used to support other wall coverings.

Window stool Molding that connects the window sill with the interior of a room. often referred to erroneously as the window sill.

Wood rasp A hand tool used to shape rough edges or curves in wood.

I hope you found something that you needed thanks for reading this page on carpentry dictionary terms.