Have drawing from architect of a ceiling with a 7′ radius.
The curved section of the ceiling is roughly 12′ long and 9′ wide. Ceiling joists run the 12′ dimension and the curved section is 9′ wide.
The arc is about 35 or 40 degrees at 7′ radius.
I plan on first adding 1×3 strapping on 16″ centers across the bottom of the joists and then applying the drywall (12′ sheets) to the strapping.
This will produce the needed ceiling curve with no butt joints. This is very desirable as the resulting curved ceiling will be lit from the bottom edge by concealed florescent lights running in the 12′ dimension – thus forming a huge faux skylight in an upscale kitchen.
I have bent drywall before by wetting the back, bending and screwing in place.
Here’s the question – does anyone know the practical limit for bending 1/2″ drywall WITHOUT WETTING??
I would like to glue the drywall in addition to screws — have a feeling that the glue will not stick too well to wet drywall.
I have also thought of wetting and “pre-bending” the drywall, allowing the sheets to dry, then installing after drying. Sounds like a hassle, but I think it will work.
Thanks for any insight!
Jim
Replies
This may not help you, but right now drywall is cheap. Grab a 12' piece and give it a whirl. I dont think it will go that far but it may.
how about two layers or 1/4" or a single layer or 3/8?
1/2 is awful hard to bend to a tight radius without scoring the back, and it looks like #### without an amazing taper.
Clinkard:
Yeah, I agree. The last time I did something like this I had to match the radius of a huge existing half round picture window at the top of a foyer entrance. I framed the radius using 3/4 plywood matched to the window. By being careful, I was able to screw right into the edge of the plywood and I used 12" centers. The key, though, was using two layers of 1/4 drywall, which was easy to bend and which was lighter to work with too. I staggered the joints. It came out perfect, and there was not all that much spackling to do since the edges of the drywall fit the curve well.
John
Longtime rocker here. You should be able to do it by wetting, possibly dry, but 7'R. is pushing it.
I am with the other poster. Throw one up and see if it works.
I also think your idea of forming it is not a bad idea.
Honestly I don't work with 1/2" that much, we use 5/8" and 1/4" over 3/8" for curves
Good luck, post some pics. It sounds like a nice kitchen.
Mike
Trust in God, but row away from the rocks.
A 7' radius is not the problem but it will take you long to do. Try 1/4" High Flex drywall made by National Gypsum..it bends to a radius of at least 2' without wetting and use a double layer.
I've done pre-bending before. I made up some sawhorses that I could lay a sheet of drywall on, face down. The heights of the sawhorses were approximated my final radius. Then, I would lay a piece of drywall on the sawhorse and spray it with a garden sprayer every time I passed while doing other work, letting the weight of the DW do the work. After it got to where it needed to be, and dried a bit, I just stood it on edge until it was installed. Not really that much hassle, if you've got the space. Really takes no time, since you can do other stuff while the DW is "working".
Mike Hennessy
Pittsburgh, PA
I will have the space. This sounds like a good idea / technique.
Thanks.
Jim
Never underestimate the value of a sharp pencil or good light.
I will also vote for pre-forming. Save the doubled 1/4" for seriously tight radii.
Thanks for your insights.
Based on what I am hearing evrybody thinks that the needed bend may not work dry.
Here's my order of possible solutions:
1) Try it dry - might work - if so all problems are solved.
2) Pre-form the sheets.
3) Use either double 1/4" or 3/8" then 1/4" - this is the least desirable solution since this will require butt joints within the curved ceiling.
This is what I would consider an "extreme lighting" situation. Someone said "it will looks like #### unless you have an extreme taper" - the taper is me - I am good but slow and don't really want to spend days on the scaffold fiddling with this ceiling section.
Thanks to all.
Jim
wait until you see the price of 1/4" bendy drywall.
!
carpenter in transition
Wait till he adds up the labor cost in wetting it, preforming it, if it breaks when it's wets, then do it again and maybe again! If it's on a ceiling when the board is wet, will the screws hold..doubt it!
Use the ButtTaper,http://www.butttaper.com. Overlap the butts with drywall adhesive 6" on each side of the two butts, use 1-5/8" cement board screws (only that type..nothing else) and no curvature on the finished butts..each butt will take about 2 minutes in finishing it. It don't get easier!
i'm don't know if i would use a butt taper in the middle of the outside radius. great product, i'm just not sure that's the best spot for it with the drywall under a lot of tension.
carpenter in transition
Or he should double up the studs where the last butt joint will fall, use glue and screws and DuraBond on the first two coats..been there and done that.