noun
joist
JOYST/dʒɔɪst/
A horizontal beam that supports a floor or ceiling.
Each wooden joist supports the floor above the unfinished basement.
Etymology
The underlying image is of boards lying down on a wooden beam. The verb meaning “to lie” thus supplies the name for the support beneath them.
In context
When you have a ceiling joist that doubles as a rafter tie, that changes everything because a rafter tie, well, they're doing structural work, not just holding up the drywall.
More examples
- The carpenter replaces a cracked joist beneath the kitchen.
- Insulation fills the spaces between the ceiling joists.
- Steel joists support the concrete floor of the office building.
Forms
joist · joists
Similar words
- beam
- A broader term for structural supports, including joists.
- girder
- A main supporting beam that often carries smaller joists.