# Curved drywall - smallest radius.



## TheVampire (Jul 27, 2008)

Putting up a wall that will have a "portal" through it. Bottom of portal is flat and top is arched. Size is 20" wide and 10" high. Can I wet and bend 1/2" drywall to make the inside of the arch without it breaking? Can I get a curved bead that will fit or be shaped to this size? Thanks.


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## Sir MixAlot (Apr 4, 2008)

1/4" drywall is the best for bending. 1/2' will bend but not as much. And, yes they do make a bead for curves. Home Depot or Lowes sell's it.:thumbsup:


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## TheVampire (Jul 27, 2008)

Great! Thanks for the tip on the 1/4" being better.


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## bjbatlanta (Jul 16, 2008)

Cut your pieces to the size you need, sponge them down until nice and damp, stand against the wall (with the bottom out a foot or so from the wall) overnight and they'll take on a nice bend for you to start with. Dampen again and EASE them into the radius to prevent breaking (hopefully). Use two layers. Often, even if the first layer cracks or breaks between the framing members, the second will bow around without breakage. Best of luck.


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## TheVampire (Jul 27, 2008)

I was planning on cutting a few layers of 3/4" plywood in the appropriate radius and using that between my studs to frame a base for the drywall to sit against. Does that sound like a good approach?
Also, what's the name on the curved bead. I looked in Lowes and could not find it. Thanks for the tips.


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## bjbatlanta (Jul 16, 2008)

I don't know if you'll get 3/4" plywood to bend around a radius. I've seen 1/4" masonite used on curves. Home Depot sells Strait Flex (at least in this area) and there is a type made for arches. Try them.


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## Termite (Apr 13, 2008)

3/4" plywood pieces are often used in curves to provide support. As bjbatlanta said, don't try to bend it. Just cut small pieces and attach with small nails or some trim screws.


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## bjbatlanta (Jul 16, 2008)

I'm thinking I misinterpreted your use of the 3/4" plywood after thinking about it. If you meant use it for the faces of your radius, like a door header, then yes, that will form your opening between your studs. Just use one piece on either side. Add 2"x4" blocking every few inches (almost solid) to form the inside to fasten your 1/4" drywall to. Use glue to stick the drywall to the radius; as few nails/screws as possible. They will tend to break the drywall in a tight radius. If you can, just nail the ends and let the glue hold in the middle. The Strait Flex (Arch Flex) comes in a roll and will be mudded on like tape. I'd use a setting type compound for extra holding power.


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## TheVampire (Jul 27, 2008)

Slight misunderstanding here. I'm not planning on bending the plywood. What I am going to do is cut the plywood out in the shape of my portal arch, although slightly bigger. I would cut 2 or 3 pieces like this and sandwich them together, then place them inbetween the vertical studs and on top of the stud used for the bottom of the portal. Then that gives me a solid perfect curve on the inside to form my drywall up against. Without drawing out a picture I really can't explain it better.

EDIT: After posting this I saw BJ's new reply. Yes, that's the kind of idea I was having, but minus the 2x4's to block it out. I understand that the glue would be better but will it hold when the drywall is damp / wet from me bending it?


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## bjbatlanta (Jul 16, 2008)

I thought I was misunderstanding you. Yes, that will work, as will the 2"x blocking nailed/screwed in between.
Once the drywall itself dries, the glue will also dry. The nails/screws on the ends will hold the rock in place until everything is dry. You may get away putting a tack or two in the outside edge as you go. Fastening the middle tends to break easier. You don't want the drywall TOO wet when you're working with it or it will fall apart (paper will turn loose from the core of the board). You just have to take it slow and if it feels like it's about to pop, stop and dampen it some more. Good luck.


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## Benjamin B (10 mo ago)

Well, it’s been 14 years since you’ve posted your question, but there are always people looking for knowledge, so here goes.
Plywood cut to a radius is probably the best way to do this and create a fair curve. Treat it like a stud wall and block every 16” or a bit less.
Wetting down a 1/4” sheet of drywall is the right approach, and always sheet in two layers.
For a curved corner bead, you have two options. You can use these vinyl corner beads for inside or outside single corners:









Trim-Tex Corner Bead & Archway


Original corner bead design featuring a slight radius on nose. Archway minimum 10" inside radius or 18" outside radius.




csrbuilding.com





Or these to cap the edge of a 2x4 (4 5/8”) wall, such as the archway you described. If using the fast cap you can get away with a single layer of 1/4” drywall, or even a doubled up Masonite backer. 









Trim-Tex Fast Cap & Archway


Finish doorways, wall ends, kneewalls, and closets by eliminating the need for the drywall face and 2 corner beads. 4 5/8" Fast Cap is designed for 2 x 4 wood studs only. 4 7/8" Fast Cap can be used with wood studs or 3 5/8" metal studs. Archway minimum 15" inside radius or 28" outside radius.




csrbuilding.com


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## Mike Milam (Mar 3, 2017)

Did something similar on a house we had in the mid 80"s.


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## jeffnc (Apr 1, 2011)

If you need to use thicker drywall to match up with other drywall, or if you need to make a radius that is a little too much even if the drywall is wetted and bent, you can also score the drywall on the backside every half inch or so and then it will easily curve to whatever shape. Of course this destroys the integrity of the drywall, so you wouldn't want to do that anywhere you needed the drywall to be strong. But if you have solid wood behind it it would be fine.


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## Mike Milam (Mar 3, 2017)

I took strips log enough to get to the flat areas on each side of the curve and set my table saw at 1/4-inch depth and cut across the pieces every 1/2 inch.


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## Nick.J (11 mo ago)

according to my experience 1/4" drywall is the best for bending. Any body also tell me the best paint for drywalls?


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## HotRodx10 (Aug 24, 2017)

For a small area, such as a doorway arch, I would not try to use drywall at all. I would use the thinnest plywood or hardboard I could find that has a 'rough' face to curve around the arch, add the corner bead, and then mud it.


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## Old Thomas (Nov 28, 2019)

Take a look at this by the Gypsum Association: https://www.gypsum.org/wp-content/uploads/2011/11/GA-226-08.pdf


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