All about grout

Keep dirt and moisture out: How to seal shower grout

Since grout is porous, you’ll want to learn how to seal shower grout to prevent discoloration caused by ingress of fluids and the resulting formation of mold and mildew. If you follow the instructions below on a regular basis, you won’t need to scrub your grout lines clean!

The right product for sealing shower grout

When you approach this task, your first question is probably, “Do I need to seal shower grout?” Yes you do, if you want your shower to stay sparkling clean.

Next up is, “What is the right product for sealing shower grout?” Since no single sealer is ideal for all projects, this question is not as easy to answer. You need a sealer which is compatible with your tiles’ material and can tolerate the high level of humidity in the shower.

While choosing a product, you will encounter penetrating sealers and membrane-forming sealers. Opt for one of the penetrating sealers, because they are better suited for damp areas. They consist of tiny latex or silicone particles that fill in gaps in porous grout, repelling moisture.

You also need to consider which type of applicator is right for sealing your shower grout. Aerosol spray-on sealers are commonly used because they are convenient, but there are better options in the following situations:

  • Use a sponge if you have very thin grout lines and unsealed tiles.
  • When dealing with glazed tiles and your sealer won’t adhere to them, seal only the shower grout lines using an applicator brush.

How to seal shower tiles and grout 

Once you have selected a grout sealer, look around your home and gather the following items to seal your shower grout:

  • dish soap
  • vinegar
  • warm water
  • cotton rags
  • toothbrush
  • sponge, applicator brush, or aerosol sprayer
  • extra grout for repairs

You need to apply up to 3 coats for adequate protection (see step 8), depending on your product and the amount of wear and tear in your shower.

  1. Clean and repair the grout. Use a toothbrush dipped in soapy water to scrub away as much grime as possible. To remove stains, use a 50-50 solution of vinegar and water afterwards. Repair any cracks or gaps in the grout lines with extra grout (see its application instructions for more information). Work on one grout line at a time.
  2. Let the grout dry.
  3. Familiarize yourself with applicator usage. Read the product’s instructions on how to seal shower grout with the applicator you have chosen before proceeding.
  4. Apply sealer. Seal the shower grout slowly and deliberately, working either from right to left or left to right to ensure you don’t skip any lines.
  5. Remove excess. Wipe off excess sealer with a cloth as you proceed. You must remove sealer before it starts to dry. The product’s instructions state exactly how much time you have, but 5-7 minutes after application is a good rule of thumb.
  6. Let it dry. Wait at least one hour. If in doubt, consult the product’s instructions.
  7. Apply a second coat. Repeat steps 4 to 6.
  8. Test. Place a few drops of water on the sealer’s surface to test whether the seal is sufficient. If the liquid beads into droplets, the seal is strong enough. If not, repeat steps 4 to 6 to apply a third coat.
  9. Let it cure. Let the tiled space dry and cure completely before using it. The sealer’s instructions tell you how long you must wait (generally 24-48 hours).