Easyboard OVER drywall?
I know it sounds odd, but read on:
Above my vanity light fixture there's a chase which means it's only going to clear the light fixture by a few inches. There's nothing in the fitting literature about clearances, but it's halogen so will probably put out some heat. I was considering one row of tiles (I'm using 8" tiles, most likely, because I have a bunch of them, and I'm out of money.)
I was going to attach them directly to the drywall of the chase (using methods of attaching to ceiling I've read ) - probably 3-4 tiles in all, and use some sort of Schluter edge. It's not a lot of tiles but it will be directly above a porcelain sink.
Someone told me under code rules I'll need to remove the drywall and use backerboard, but could I put the backerboard on top of the drywall? It'll be a bit thicker but I can probably get a Schluter edge that'll work with that.
Bad Idea? It just seems like a lot of work to remove sound drywall AND a corner edge piece, neatly, when I could go over it with backerboard. As for moisture, there may be steam but no direct water contact.