How to waterproof bathroom walls
Although bathroom walls are made from different materials, the majority are covered with porcelain tiles. Porcelain tiles not only give your bathroom a bright and shiny appearance, but they are also highly resistant to water.
This is particularly true if the grout between the tiles is intact, and the walls have been properly waterproofed with a sealant. Waterproof your walls when the tiles are first installed or when they need to be refurbished following normal wear and tear.
Scrub the bathroom walls with warm water and a sponge. Scrub any tiles that are severely stained with a commercial porcelain cleaning product and a sponge.
Inspect the tiles for any missing pieces of grout. Fill in any missing areas with a silicone grout sealer and paint brush. Wipe off any excess sealant from the tiles with a wet rag.
Let the grout sealer dry for an hour. Apply another coat of grout sealer. Leave the tile untouched for at least two days.
Apply an all-purpose porcelain sealer with a paint roller or spray can in long strokes. Apply the sealer in the corners of the walls with a smaller paint brush or spray can. Spread out any excess sealant over the tiles.
Allow the recommended drying time on the label of the sealant.
Spray or roll on another layer of sealant. Add a third coat for walls exposed to a lot of water, such as those in showers.