How to reseal shower and floor grout
Drop water on the grout. If it soaks in instead of beading, it's time to reseal. To reseal grout, clean it, repair any cracks, let it dry, then brush on a penetrating sealer and wipe the tile within about 10 minutes. Most showers need this about once a year.
How often to seal grout in a shower or on a floor
Published intervals vary, so use them as a guide and let the water test decide.
| Where | Reseal about every |
|---|---|
| Heavily used shower | 6 months |
| Typical shower or busy bathroom | 1 year |
| Guest bath or low-traffic area | 2 years |
| New grout | Wait at least 48 hours after installation, then seal |
| Epoxy grout | Never. It's waterproof and doesn't need sealer. |
Grout sealer and what else you need
Pick a penetrating sealer for showers and other damp areas. It soaks into the grout rather than sitting on top. Membrane-forming sealers coat the surface, which can trap moisture in a bathroom and lead to mildew. They also won't stick to glazed tile.
- Penetrating grout sealer. A bottle with a rolling tip or a small brush keeps it on the grout lines.
- Grout cleaner and a stiff brush
- Dry, clean cloths
- Grout for repairs, if you find cracks
- Good ventilation, and any gloves the label calls for
Skip aerosol sealers. They leave overspray that hazes the tile, waste product and lay down a thinner barrier. For marble and other natural stone, check that the label names your stone before you buy.
How to reseal grout in seven steps
- Run the water test
Drip water on grout in several spots, especially the shower floor and lower walls. If it beads, you can wait. If it soaks in or darkens the grout, reseal.
- Clean and repair
Scrub the grout and fix any cracked or crumbling sections. Sealer locks in whatever it covers, so dirt stays under it.
- Let it dry
Bob Vila's guide allows about 45 minutes after cleaning, but your sealer's label has the final say. Damp grout won't take sealer well, so wait longer after a recent shower.
- Apply the sealer
On glazed tile, work only along the grout lines with a brush or roller bottle. Keep the coat even.
- Wipe the tile
Let it sit about 10 minutes, then wipe excess off the tile with a dry cloth. Leave it and you'll get a foggy film that's hard to remove.
- Add coats until water beads
Wait about an hour between coats. Most jobs need one to three. Test with a few drops of water after the last one.
- Keep it dry while it cures
Cure time is usually 24 to 48 hours, depending on the product. Plan around it if this is your only shower.
When you shouldn't reseal shower grout yet
Sealer protects sound grout. It won't fix failed grout or a leak. Look closer if you see:
- Cracked or crumbling grout. Repair it before sealing.
- Mildew that returns soon after cleaning, even with fresh sealer
- Loose or hollow-sounding tiles
- Stains on the ceiling below the shower, or soft spots in the wall or floor around it
How to reseal grout yourself, or when to call a tile pro
Resealing is a straightforward DIY job. Bring in a tile contractor if tiles are loose or the grout is failing across a whole wall. If you see signs of water behind the tile or below the shower, get a plumber or tile pro to find the source before you seal anything.
Grout sealer questions
How do I know if my grout needs resealing?
Drip a little water on it. Water that beads means the sealer is still working. Water that soaks in or darkens the grout means it's time to reseal.
How long after sealing grout can I shower?
Sealers usually need 24 to 48 hours to cure, depending on the product. Follow the time on your label.
Does epoxy grout need sealing?
No. Epoxy grout is waterproof, so there's nothing for a sealer to do. Cement grout is the type that needs sealing.
Sources: Bob Vila, housedigest.com
General guidance for U.S. homes, not professional advice. For gas, electrical and structural work, call a licensed pro.