Drywall – How to repair walls which have two layers of wallboard

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We have ordered new counter tops which will be installed over existing cabinets. We had the back splash demo-ed, and found there are 2 layers of 1/2" wall. What is the best way to repair and prep for new tile without adding two layers to the patches? Should we attach wood to the studs? Add 2 layers again?

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Best Answer

I don't believe you have two layers there. I think that's what I had in my previous home, which is what I called hybrid drywall--a layer of 3/8" gypsum panels covered with about the same thickness of conventional plaster. The system was used in the 1950s as a transition between conventional lath-and-plaster and modern drywall.

In my case the gypsum panels were 18" high and had heavily rounded, fully wrapped edges. I really liked it since it was extremely tough from a daily living standpoint but still easy to cut with a keyhole saw, say for new electrical boxes.

I'd fur out your framing and install 1/2" drywall (or 5/8" for better stiffness, or cement board) flush with the original surface. I often used 1/8" hardboard or other furring and 5/8" drywall with good results, since the original wall was about 3/4" thick. It did vary somewhat, as plaster does, so check your thickness carefully. It's better to start slightly behind the original wall than to protrude beyond it and create a bump.

It's a good opportunity to flatten any wonky framing, so use a long straightedge horizontally on your furring to check plane before you install the drywall.