I have begun the process of hanging drywall for the first time in my second story gut rehab. The ceiling panels are mostly up. I have a few questions:
- I have angled ceilings for a short run. How are drywall panels hung at the off angle inside corner joint? I was planning to run the ceiling panels long and butt the angled panels up to them. after I was going to use a flexible inside corner product for a good line. Is this the right way to butt panels? See diagram, I was planning the arrangement in black, is this correct or is something like the red appropriate?
- The ceiling panels I hung have a couple spots where adjacent panels aren’t quite flush. the variation is maybe 1/8 max. This seems like a lot. Is this normal, does it just come out with finishing or does it need to be addressed before that point? Looks like it mostly happened between joists.
- I have polyiso attached to the angled sectios and secured with furring strips to the rafters. The drywall will be attached to the furring strips. Where partition walls intersect the angled foam/furring do I need to float the corners or do something special? I am worried about the foam expanding and contracting and causing cracks
I have some other pictures I will attach when I get them converted to an accepted format.
Thanks
Replies
in regards to the rock intersections. running it long or having the angels butt up doesnt really make much difference. tighter is better but honestly 1/8'' at your worst spot is not a problem, i would consider it pretty good for a DIY sheetrock job.
not following your concern about the polyiso expantion???
bac478 wrote:
3. I have polyiso attached to the angled sectios and secured with furring strips to the rafters. The drywall will be attached to the furring strips. Where partition walls intersect the angled foam/furring do I need to float the corners or do something special? I am worried about the foam expanding and contracting and causing cracks.
If I'm understanding you correctly, with the polyiso behind the furring strips, any bounceback from the polyiso will not move the furring strips. If you have unsupported corners (no framing or furring at the corner to screw the drywall to) where drywall panels will meet, you can use drywall clips.
I was worried about having one drywall panel attached to the wood wall framing and another to the furring strips on top of foam. I picture differential expansion and movement since they are attached to significantly different substrates. Floating the corners or using clips attached to an added (compared to current photos) corner framing member would isolate the corner joint. I was thinking along the lines of how wall/truss intersections are handled with clips because of uplift. In this case the truss is the foam/furring plane.
Not shown is 2x3 furring that is going on the framed walls. None of the partition walls are framed yet either. I was thinking of adding an angled 2x4 in the corner attached to the exterior wall and using it to support the drywall just like how an additional rafter is added on the gable wall of a cathedral ceiling to attach drywall. Then the drywall would be attached to the second to last furring strip about 18 inches away from this added corner member. The 18" would allow flex and keep the corner from cracking. I can try to make a picture later.
The thing is, if you screwed the furring strips too tightly and compressed the foam, if the foam ever pushed back it's pushing against furring strips that are screwed to the framing. The screws aren't going to give. I suppose you cou;d say over 16" of furring strip between the rafters the strip could bow a bit. But I think that's being overly cautious.
But it's your house, not mine. Not meant as a criticism. I just understand your concern.
So, FWIW...when I finished off my attic about a dozen years ago, I hung 2" polyiso on the rafter edges from peak to plate and secured them with furring strips and screws. The gable end walls got 1" polyiso over the studs and the drywall went right over the polyiso, no furring strips.
I was careful to not overdrive the drywall screws on the gable end walls because I didn't want to overcompress the polyiso. With no furring strips, if the compressed polyiso ever bounced back, it could blow the drywall through any fasteners.
The kneewalls are just drywall over the kneewall studs. At the kneewall/sloped roof intersection, there is a small section where the mud cracked, maybe 18"-24" of crack over 90 linear feet of joint. Nothing horrific. It doesn't bother me enough to want to patch it.
It's a single large room (850sqft or so) so I installed some faux beams to break up the ceiling plane and there's wainscot on the walls. So in retrospect, there's not much drywall to see. lol
I pulled a couple of the beams down a few years ago to run some wire, there were no cracks where the ceiling plane (drywall over polyiso with furring strips) meets the gable end walls (drywall over polyiso).
Drywall joint
bac478,
red ink would be prefered, but since ceiling is installed..... install the lower portion of the wall next ... then cut the sloped ceiling sheet at the needed width...then cut a 45 degree cut on the top and bottom edges that will go against the ceiling/wall....doesn't have to be a perfect fit...mud covers a lot of sins.......I see your hanging 5/8 board, I would also strongly suggest you double-screw the flat ceiling portion to prevent sagging over time(gravity always wins!). double-screwing simply means you put two screws with-in a 1/2"-3/4" of each other at each "screw" location.
Good Luck and hope this isn't too late to help
Geoff
Geoff - had sheets of 5/8 that I got when a local lumber yard closed. Used them because the joists are 24 OC. I also glued all the drywall with polyurethane adhesive. Unfortunately I ended up with the black joint. I'll probably use trimtex for the obtuse inside angles so that should help. Thanks for the advice.