So, I’ve about installed all the cement board for my bathroom tile renovation around the 3 sides of the tub. There is approximately a 2” gap between the corner of the room and the bath tub. For the 2” gap that runs the depth of the tub, should I use cement board or dry wall? I’m not planning to tile this – it was previously, but going down the side of the tub I recognize it’s at risk of water damage.
The tile will start at the bathtub and go from the tub up to the ceiling.
Best Answer
The spot next to the tub is a trouble area. I have found that the more robust the wall material is (i.e. less porous, harder) the longer it will last without water damage, that is why I tiled that area next to my tub.
I recommend cement board. Furthermore, I encourage you to use a harder plaster material (instead of joint compound) such as a "setting-type" plaster (e.g. water putty, "fixall", plaster of paris, etc.) as the base coat on top of the cement board and at the joint.
Setting-type plasters are a bit hard to work with because they have a short working time, they set hard, and are difficult to sand or smooth after they set. However, hard plaster as a substrate to normal joint compound should help prevent structural damage in case of water contact over time. NOTE- all plaster is porous, but hard plater is less porous. Use joint compound as the final coat so you can sand it flat and smooth, use a high quality paint with a gloss, and caulk well.