Most cement-based grout should be sealed. Sealing helps grout resist water, stains, and dirt, which keeps the joints looking clean and extends their life. Epoxy grout is the exception, since it is naturally non-porous and does not require a sealer.

Why cement grout needs sealing

Cement grout is porous. Left unsealed, it soaks up water, spills, soap scum, and grime, and it can darken or grow discolored over time. In wet areas like showers, pools, and backsplashes, that same porosity lets moisture reach the substrate, which can lead to bigger problems down the line. A sealer fills the microscopic pores so liquids bead up instead of soaking in.

Penetrating vs topical sealers

• Penetrating sealers soak into the joint and protect from within without changing the look. They are the best all-around choice for most tile grout.
• Topical sealers sit on the surface and can add sheen, but they wear faster and are less common for grout.

How to seal grout, step by step

1. Let new grout cure fully (typically several days) before sealing.
2. Clean the grout and let it dry completely.
3. Apply the penetrating sealer along the joints.
4. Wipe excess off the tile before it hazes.
5. Allow it to cure, then test with a few drops of water.

How often should you reseal?

A quick test tells you when it is time: drop water on the grout. If it beads, the seal is intact. If it soaks in and darkens the joint, it is time to reseal. High-traffic and wet areas need it more often than a dry backsplash.

When you do not need to seal

Epoxy grout is non-porous and does not require sealing. If stain and moisture resistance without maintenance is the goal, an epoxy system removes the sealing step entirely.

SGM products

Protect cement joints with Southcrete Clear Penetrating Sealer and Grout Release (SC901). For a maintenance-free, non-porous option, see the EGS Mortar Grout System. Keeping joints clean first? Start with Safe Clean Crystals.