Arches

[AllThumbs]

I have existing square arches in my home that I would like to convert to curved. Some of the arches are of standard wall thickness (2x4) and others are about 3 foot thick. I will be doing everything except for the taping and texturing.

I was going to attach 2x4 blocks to the existing sheetrock and use screws long enough to sink into the existing framing studs. Then I would attach OSB that has already had the curved arch cut into it. Then attach some more 2x4 blocks to the inside of the bottom portion of the OSB (the arched portion). Then attach the new sheetrock to the top of the OSB (cut to the same shape as the OSB).

Should I be using thin sheetrock to make the bend for the bottom portion of the arch? Should I scrape some of the existing texture off the existing sheetrock to allow taping from old sheetrock to the new sheetrock?

I attached a crude pic.

Thanks for any other suggestions.

[SDContractor]

Hello Thumbs

Funny I should run into this post as I just finished putting 9 arches into a new house I am building. Your plan sounds fine for framing them almost the same way I do them. As far as the inside of the archway we always use 1/4" luan and bend it. The taper then usually muds over it or uses wire lath on it and muds it.
And yes scrape some of the old texture of to make Taping easier.

There is also a product called HighFlex drywall which is 1/4" very flexible and can be used where I suggested the 1/4" luan.