Re: building a ceiling in the garage.
My builder was not too keen on the initial idea of connecting 2x6 ceiling rafters, about half-way down from the ridgebeam, with 2x6's (kinda forming a system of "trusses"),
then hanging drywall from, or attaching it on top of, the "truss" beams.
- The alternate plan is based on my living room ceiling - consisting of 4"x8" joists, 48" on center,
supporting tongue-in-groove pine 1x8 boards, which sit on top of the joists.
- Will this work in my garage considering (1) the span from top sill plates of the two walls which will support the ends of the 4x8" joists are about 19',3" or so
from each other; (2)we are soundproofing the room, so we plan to add, on top of the tongue-in-groove 1x8" planks, a single layer of 5/8 fire rated (National Gypsum Fire Shield) drywall sheet,
followed by a single layer of 5/8 Durorock/Wonderboard on top of that, followed by batts of insulation as the top layer.
I can't seem to find specifications for the maximum ceiling joist spans where 4x8's are involved. Although it seems that 2x8's are rated to span, as ceiling joists, 19 or so feet if 24" on center, here we are using 4x8's - -
- Can we install the 4x8" joists 48" on center (again, a 19' 3" span across the garage) ?
One friend suggests that for additional support for the joists, that we attach 2"x4" "hangers", to the top of the 4x8"s via "L" brackets, and then bolt the other end of the 2x4 hangers to the 2x6 rafters, about 1' to 2' from the ridgebeam
- Any other tips for further securing this ceiling system ?