Definitions of Terms under Alphabet R
- Rough Opening
A structurally-framed opening in a wall for a door or window.
- Riser
A term which describes the part of an adjustable sill which can be moved up or down by turning adjusting screws.
- Reveal
The offset or space between edges of parts.
- Rail
In stile and rail doors, horizontal pieces at the top and bottom edges at intermediate points, connecting the stiles together.
- Rabbet, Rebate
A groove or step cut along the length of the edge of a piece of wood that is to be joined to another with a corresponding tongue or ledge cut into it.
- R-Value
A number which describes in relative terms the ability of a material or assembly to resist the flow or transmittance of heat. Assemblies or materials with high R-values are better insulators than those with lower R-values.