I need to install a drop ceiling. The current ceiling is 12′ high, and the new one will be 8′, framed and drywalled. The room will be approx 14×20 when completed. My first question is what size lumber (2×8, 2×10, etc?) to use to frame the new ceiling, given the 14′ span. I plan to place the joists on 16″ centers. The new ceiling needs to be strong enough to support the drywall and an occasional person up there doing maintenance.
In addition, while one side of the 14′ span will rest on a partition wall I’m adding, the other side must be attached to the existing 12′ high walls. So my second question is how should I attach it? Is it sufficient to nail a trim joist to the side of the existing wall studs and toenail the 14′ joists into that? Or do I need to use joist hangers?
Replies
first,
In a room that large, an eight foot ceiling will feel pretty low. Proportionatly, you would feel more comfortable with at least 8'6" or so. Try to go to nine feet with it.
You will want to use lags to attach the ledger joist to the one wall, then use hangers to hook up the other joists to it. What will be getting maintained and will it be loaded onto these joists also? to be safe, you probably want 2x8s tp sapn 14' 2x6 might handle it, but I would be afraid that you would be repairing minor SR cracks every time somebody worked up there.
Excellence is its own reward!
Forget lumber- get some RigidX grid from a commercial drywall supplier. It's like heavy suspended ceiling grid, and goes up the same way (hung from wires). The bottom edges are about 1 1/4" wide, and you just screw the drywall to it. It's much cheaper, straighter, and faster than wood.
Bob
That commercial background is showing, Bob.
But can he walk up there on it?.
Excellence is its own reward!
It shows when it's beneficial...lol. There's lots of commercial stuff that should be used in residential but isn't- look how long it took for metal studs to move over (though in limited applications).
As far as walking on it- yes he could (with enough wires holding it up)- been there, done that. Though with only a 3'-4' space above as it's been described. I doubt there'll be much "walking" being done.....
Bob
I can't imagine why you want to install a gyprock ceiling below a space with maintainable utilities in it: that's specifically what suspended ceiling panels are for. I think you'd be much better off hanging a grid and panels; as Bob K remarked, with only 3-4' of headroom above it, you won't exactly be walking around up there to maintain whatever it is. With removable panels, you can pop out a panel and work from a nice solid stepladder instead of teetering around on your tip-toes on 2x's or Bob's commercial rails.
If you do insist on framing it with wood, you should lag or thru-bolt the ends of the joists to the studs, balloon style. NBC of Canada requires #1&2 SPF 2x8 on 24" centers or 2x6 on 16" centers for the span you mention, as long as the 'attic' is not accessible by a stairway.
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?