QUESTIONS
Should I use grout sealant once my bathroom (including shower) has been fully tiled?
Updated 07/26
By: Kim Staples
Reviewed: Content Team
Yes, in almost all cases. Standard cement-based grout is water-resistant, not waterproof, so left unsealed it will gradually absorb moisture, soap, and shampoo residue, leading to staining and, eventually, mould. The one exception is epoxy grout, which doesn't need sealing at all.
Why cement grout needs sealing but epoxy doesn't
How often to actually reseal it
The one thing grout sealer doesn't replace
How to apply it properly, step by step
How to tell when it's time to reseal
When to bring in a professional tiler
Find a vetted tiler near you
Why does grout need sealing?
Cement-based grout is porous. Left unsealed, it absorbs water, soap, and shampoo residue over time, which leads to staining and creates the damp conditions mould and mildew need to take hold. A sealant blocks that moisture from soaking in, in the first place, protecting both the look and the integrity of the grout.
Grout sealer isn't the same as waterproofing. Sealer reduces how much moisture the grout itself absorbs, but the real waterproofing in a shower comes from the membrane installed behind the tiles before they were fitted. If a shower is leaking into the wall or floor below, sealing the grout won't fix that; it's a different problem entirely.
Which grout doesn't need sealing?
Epoxy grout is the main exception. It's a resin-based, non-porous grout that resists water and staining without ever needing a sealant, which makes it a popular (if pricier) choice for showers and other consistently wet areas. Urethane grout is another increasingly used option that combines good water resistance with more flexibility than standard cement grout.
If you already have standard cement grout, though, sealing it is the right call rather than replacing it, unless you're regrouting anyway.
How often should you reseal grout?
This is the detail most guides skip, but it matters: sealing isn't a one-off job.
Shower and other wet areas: reseal roughly every 1-2 years, since these grout lines face constant water exposure.
Other bathroom areas, floors, and less exposed spots: reseal roughly every 2-3 years.
Epoxy grout: never needs resealing.
Rather than sealing on a fixed schedule, you can check directly with a simple water test: drip a few drops of water onto a dry grout line. If it beads and sits on the surface, the seal is still working. If it soaks in and darkens the grout, it's time to reseal.
If your grout is already stained, cracked, or crumbling rather than just due for a reseal, our guide to regrouting cost covers when it's time to redo it properly instead.
How to apply grout sealant
If you have existing cement grout and want to seal or reseal it, here's the process:
Ventilate the room well before starting, and wear gloves, protective goggles, and a mask.
Clean the grout thoroughly and let it dry completely. If you've just had new tiling done, wait the full cure time recommended by your tiler or the grout manufacturer, typically 48-72 hours, before sealing.
Apply the sealant, following the manufacturer's instructions, using a brush or dedicated applicator.
Leave it to dry for at least 2 hours.
Test a dry area with a few drops of water. If it's absorbed within 60 seconds, apply a second coat.
Let it dry completely for at least 8 hours before using the shower or bath.
Wipe any excess sealant off the tile face within a few minutes of application. Left too long, it can dry into a hazy film that's genuinely difficult to remove, especially on textured or unglazed tiles.
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Hire an experienced local tiler
If you'd rather have it done properly, or you're not confident distinguishing epoxy from cement grout, or diagnosing whether a problem is a sealing issue versus a waterproofing one, a professional tiler can assess and sort it properly.
How much does regrouting cost in 2026?
Give your bathroom an instant makeover with our regrouting cost guide. Eradicate old, damaged grout to transform your tiles. With costs, great tips and much more.
Before you seal (or reseal)
Frequently asked questions
Yes, standard cement grout benefits from sealing wherever it's used, though less-exposed areas can go longer between reseals than a shower.
Drip a few drops of water onto the grout line. If it beads on the surface, the seal is still working. If it soaks in and darkens the grout, it's time to reseal.
No. Grout sealer reduces moisture absorption into the grout itself, but the actual waterproofing in a shower comes from the membrane behind the tiles. If water is getting into the wall or floor structure, that's a waterproofing issue, not a grout sealing one.
For consistently wet areas like showers, many professionals consider it worthwhile, since it never needs resealing and resists staining better than cement grout over time. It's more expensive and can be trickier to apply, which is part of why some people prefer to have it professionally fitted.
Yes, it's a straightforward DIY job with basic protective equipment and the right sealant, provided you follow the cure time and application steps carefully.
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