How do I know which waterproof backer board is best for my bathroom renovation? I ripped my bathroom walls down to the studs, and now I need to put up the backer board, but there are so many products out there! What should I look for?
Lori ~ Queens, New York
Hi, Lori. The type of drywall you use on your bathroom walls depends on the type of fixtures you are planning on using. There are two types of products commonly used. The first is green board which is often mistakenly thought of as a waterproof sheetrock. Green board should never be used where it will constantly come into contact with moisture.
If your tub or shower has a fiberglass surround that goes up to a height just under the shower head, then you can use green board from the surround up to the ceiling height. A lot of people use regular drywall in the rest of the bathroom and rely on semi-gloss paint or wallpaper for moisture protection, but I recommend using green board everywhere on your bathroom walls and ceiling. It doesn't cost that much more than regular drywall and it gives you some added protection from moisture damage. It can help a lot if the members of your family like hot showers and the bathroom gets steamy on a regular basis.
If you are just using a shower pan or tub without a fiberglass surround, then you should use a cement based backer board where the walls would have been covered by fiberglass. I assume you would be using ceramic, marble, or granite tiles as a surround and the backer board should be installed everywhere the tile will be on the wall. There are a number of different manufacturers of this product, but you should know it when you see it. The product is about 1/2 inch thick and sold in 4-foot-by-4-foot pieces. It's gray in color and has a fairly rough texture. It is also very heavy because it's made from cement.
If you are having a tile company install your tile surround, you may want to check with them to see if they plan to install any backer boards. Many tile companies have a preference as to what type is used and prefer to install it themselves to ensure it's done properly. I have had tile companies refuse to warrant their installation if they didn't install their own backer boards. If you can find a tile company around Queens, New York that installs their own, it can save you a lot of trouble. As I mentioned, the product is very heavy. Cutting it for installation can also be a very dirty job.
Regardless of who installs it, take care that it doesn't extend too far past where the tile will be installed. The rough surface will need several coats of drywall mud and sanding where the exposed sections are painted or receive wallpaper.