How Many Coats of Waterproofing for a Shower?

Type of Material

• While some types of material may only require one or two coats to properly protect the substrate, others require more. For example, concrete block walls sometimes need several coats to completely coat and protect all of the natural pits and valleys and openings in the face of the block. Check the material as you go to see how it is covering the surface, and use your best judgment along with the manufacturer's recommendations.

Manufacturer's Recommendations

• At the very least, you must always apply the minimum recommended layers according to the manufacturer of your waterproofing product. Beyond that, it’s always a good idea to add an extra layer on top of whatever the manufacturer recommends. But if you want to make sure that your installation is covered by the warranty, you have to perform every aspect of the installation, from the underlayment to the finish tile, according to the manufacturer's recommendations, or the warranty will be void.

Personal Preference

• If you don’t have any concerns about the height or thickness of the installation area, you can apply as many coats of waterproofing as you feel are needed. More protection is always a good thing, but it isn’t always required. Follow the minimum requirements for your waterproofing, then add however many additional coats make you feel safe.

Water Test

• For shower pan floors, you can check the waterproofing by performing a water test. Plug the drain hole and fill the shower pan with water. Let it sit for a minimum of 24 hours. Check around the pan as well as under it if possible, such as with second floor showers. If no water appears to be leaking, your waterproofing is complete and you can begin your finish installations.