Rabbet: (also known as rebate) a recess or groove cut into the edge of a piece of machineable material, usually wood. When viewed in cross-section, a rabbet is a two-sided L shaped channel, open to the edge or end of the surface into which it is cut, which can be used to join the piece to another.
Radial Drill Press: large drill press having a head which can be moved along an arm that radiates from the machine's column. As it is possible to swing the arm relative to the machine's base, a radial arm drill press is able to operate over a large area without having to reposition the workpiece.
Radiant Heat: refers usually to form of heating system where the heating element is installed under the finish flooring.
Rafter: one of a series of structural roof members intended to support roof loads. Rafters of a flat roof are also known as roof joists.
Rail: horizontal or cross members of a sash, door, blind or other framework assembly.
Rake: (1) pitch or angle. (2) trim member running parallel to the roof slope, forms the finish between the roof and wall at a gable end.
Rasp: tool used for shaping wood or other material. It consists of a point or the tip, then a long steel bar or the belly, then the heel or bottom, then the tang. The tang is joined to a handle, usually made of plastic or wood. The bar has had sharp teeth cut into it. Rasps generally cut more coarsely than files.
Relief: carved or molded ornament that projects from a flat surface.
Retaining Wall: a wall subjected to lateral pressure (other than wind pressure), for example a wall built to support a sloped bank of earth.
Return: the part of a molding cornice, or wall surface that changes direction, usually at a right angle, toward the building wall.
Reveal: the side of an opening for a door or window between the frame and the outer surface of a wall, showing the wall's thickness.
Ribbon: narrow board fastened to studs or other vertical framing members which adds support to joists or similar horizontal members.
Rip Cut: a cut made along the grain of a piece of wood.
Riser: vertical stair member between stair treads.
Rool Roofing: roofing material comprised of mineral granules on asphalt saturated felt or fiberglass. The uncut form of asphalt shingles material.
Roof Ridge: horizontal line formed at the junction of the top edges of a roof's surfaces.
Rotary Cut Veneer: a venner cut on a rotaing lathe in a continuous sheet, similar to how toilet paper is unwound from a roll.
Rough Lumber: lumber which has been cut to size but not dressed or surfaces.
Rough Opening: an opening formed by framing members.