Yes, it would be best if you waterproofed your shower walls before tiling. The cement backing board behind the tile is not waterproof; it’s only water-resistant. On top of your tile backing board, be sure to use a waterproof shower membrane before you start installing your shower tiles.

Yes, provided you aren’t installing drywall over it. But you can skim coat it, apply new tile right on top, paint it, or stencil it. For more budget- and DIY-friendly options, you can install beadboard or apply decals. Just make sure that the current tiles are in good condition and prepped well for the paint or adhesive to stick.

Once cracks appear, it is hard to stop tiles from cracking more. If the cause of the problem is improper subflooring, underlying concrete, improper tile joint sizes, mold growth, or structural issues, the only way to stop floor tiles from cracking is to redo the entire floor, fixing the underlying issues first. If cracks occur after impact damage, hiring a professional tile contractor to replace the cracked tiles, fix loose floor tiles, and restore the grout around them can prevent further damage. It is also important to keep your tile and grout clean and maintained to prolong its life.

You can lay tile directly on a plywood countertop, but if it’s a high-traffic surface in a kitchen, it’s better to add a moisture-resistant base. Plywood is susceptible to moisture, so if dampness seeps through from the surface around the sink or where you prep food, it can cause the plywood to warp, leading to grout damage, cracked tiles, or mold growth under the surface.