- Roof beam - Roof or ceiling beam - Supporting beam - A piece of timber laid horizontally, or nearly so, to which
the planks of the floor, or the laths or furring strips of a ceiling,
are nailed; -- called, according to its position or use, binding joist,
bridging joist, ceiling joist, trimming joist, etc. See Illust. of
Double-framed floor, under Double, a. - To fit or furnish with joists.