Step 8 · Repair the Wall
Once you are certain there are no leaks, you can repair the wall. Cut a piece of cement backer board to fit the opening you created. Secure this patch to the wood studs using corrosion-resistant cement board screws. To ensure the shower remains waterproof, apply a liberal coat of a liquid waterproofing membrane over the entire patch, extending a few inches onto the surrounding existing backer board. Pay special attention to covering all seams and screw heads.