Shower tile is subjected to constant wetting and drying which can cause cracked and moldy grout. Sealing the tile and grout helps maintain the integrity of your tile surface. Inspecting and replacing grout and caulk regularly, as well as routine cleaning, are also important to maintaining your shower tile.
Sealing Shower Tiles
Shower tiles should be sealed every one to two years depending on how often the shower is used. Use latex based products to seal both grout and tile. Some tiles are too thick to absorb the sealant, so check a small area first. If the tile soaks up the sealant, seal the entire shower. If it doesn't, only seal the grout. Allow the shower to thoroughly dry prior to sealing. Apply sealant with a sponge, wait for a couple of minutes, then wipe off the excess with a damp cloth. Repeat the process the following day.
Regularly check the grout in your shower. If it shows any signs of crumbling, weakening or cracking, replace it immediately. Crumbling grout allows water to seep behind the tile, weakening the adhesive and compromising the entire tile surface. Clean out bad grout, replace it, then seal all the grout in the shower for good measure. Use latex or silicone sealers.
In addition to cracked grout, old or failing caulk can allow water seepage that damages tile adhesive, wood framing or even old backer board. Inspect all caulking around the tub and fixtures. If it's cracked or peeling, remove and replace it. Merle Henkenius from "This Old House" magazine recommends silicone caulk. He says it's more water-resistant than other materials and won't peel away from the tub.
After every shower, use a clean towel to wipe all the water from your tile and grout. Ensure the tile surface is dry, including the grout around the tub. Drying your tile after each shower prevents mold from forming in the grout. Clean your tile with non-abrasive, non-acidic products. Check with your tile's manufacturer for cleaner recommendations. If you need to clean your grout, use a soft bristled brush and a recommended cleaner.