Best grout for bathroom tiles – DIY or hire a pro?

[Tomhanks]

Hi everyone!

I recently had someone fill the grout lines in my bathroom, and I might need the same work done for another bathroom. However, I’m not sure what type of grout was used. Is there a way to figure it out? Also, is regrouting something I can do myself, or is it best left to a professional? What type of grout would be best for bathroom tiles in terms of durability and water resistance?

Thank you in advance!

[Downaski]

Hi, Tomhanks!

Figuring out what type of grout was used can be tricky, but there are a few ways to narrow it down. If the grout feels rough and sandy, it’s likely sanded grout, which is commonly used for wider grout lines (over 1/8 inch). If it’s smooth and more compact, it’s probably unsanded grout, typically used for thinner lines. If the grout has a slightly plastic-like or glossy feel, it might be epoxy grout, which is highly water-resistant and durable.

Regrouting is definitely something you can do yourself if you’re comfortable with some hands-on work. The main steps involve removing the old grout (usually with a grout saw or oscillating tool), cleaning the lines, applying new grout, and sealing it if needed. It can be time-consuming, but it’s manageable with the right tools and patience.

For bathroom tiles, epoxy grout is the most durable and water-resistant, but it’s also harder to work with. If you want an easier DIY option, a high-quality cement-based grout with a sealant works well for most bathrooms. Are you looking to match the existing grout or thinking about switching to a different type?

[Tomhanks]

I just want to know what grout was used in the first bathroom since I might need to regrout another one too. But if that’s hard to figure out, no worries, I’d still appreciate a good grout recommendation for a bathroom.

[Downaski]

If you want to figure out what kind of grout was used in the first bathroom, there are a few simple ways to check. If the grout feels rough and grainy, it is probably sanded grout, which is typically used for wider joints. If it feels smooth and dense, it is likely unsanded grout, which works better for thinner lines. If it has a slightly glossy or plastic-like feel, it might be epoxy grout, which is very durable and water-resistant.

If you are not able to determine the exact type, you could try asking the person who did the work or checking if there is any leftover grout. But if that is not an option, no worries, what matters most is choosing the right grout for your second bathroom. For the best durability and water resistance, epoxy grout is the top choice since it resists moisture and stains, but it can be more challenging to work with and more expensive. A high-quality cement-based grout with a sealant is a great alternative that works well for most bathrooms. If you are doing this yourself, unsanded grout is smoother and easier to apply for smaller joints, while sanded grout is better for wider gaps.

[Tomhanks]

Thanks for the explanation! I need to fill small gaps between tiles, so unsanded grout sounds like the right choice. Should I remove the old grout first, and if so, what’s the best way to do it? Or can I just apply the new grout over it?

[Downaski]

You’re welcome! Since you’re filling small gaps, unsanded grout is a good choice. Ideally, you should remove the old grout first because applying new grout over existing grout usually doesn’t bond well and may not last long.

To remove the old grout, you can use a grout saw, oscillating tool with a grout-removal blade, or a Dremel tool. If the grout is soft, a simple manual grout saw should do the job, but for tougher grout, a powered tool will make it easier. Be careful not to damage the tiles while scraping it out.

Once the old grout is removed, vacuum up the dust, wipe the area clean, and let it dry before applying the new grout. After applying, wipe off excess grout with a damp sponge and let it cure properly before sealing (if needed).

[Tomhanks]

Thanks for the detailed breakdown! That makes sense about removing the old grout first. Also, how long should I wait for the grout to fully dry before exposing it to moisture?

[Downaski]

You're welcome! The drying time depends on the type of grout you’re using. Cement-based unsanded grout usually takes about 24 to 72 hours to fully cure before it’s safe to expose to moisture. Epoxy grout, on the other hand, sets much faster and can often handle moisture within 24 hours, though checking the manufacturer’s instructions is always best. If you're sealing the grout (which is recommended for cement-based grout), wait at least 48 to 72 hours before applying the sealer. Once sealed, give it another 24 hours to fully cure before using the shower or bathroom normally.

A good rule of thumb is to avoid heavy moisture or cleaning for at least three days to ensure the grout sets properly. Hope that helps!

[Tomhanks]

Thanks! Can you shed some light on sealers? I don’t think any sealer was used when regrouting the first bathroom. Does it actually help with extra protection from water and moisture? Also, can I still apply it to the first bathroom even though it has been a few days since grouting and is already exposed to water?

[Downaski]

Yes! A grout sealer is definitely helpful for added protection against water, stains, and mold, especially in a bathroom where moisture is constant. Cement-based grouts (both sanded and unsanded) are porous, meaning they absorb water and stains over time if left unsealed. A sealer helps prevent this by creating a protective barrier, making cleaning easier and extending the life of the grout.

Since the first bathroom has already been exposed to water, you can still apply a sealer, but you need to let the grout dry completely first. Before sealing, clean the grout thoroughly with a mild cleaner or a grout-specific cleaner to remove any soap scum, mold, or residue. Let it dry for at least 24 hours before applying the sealer.

For application, use a small brush, roller, or applicator bottle to apply the sealer directly to the grout lines. Wipe off any excess from the tiles with a dry cloth before it dries. Let the sealer cure for the time recommended on the product (usually 24 hours) before exposing it to water.

If you’re using epoxy grout, you don’t need a sealer since it’s already waterproof and stain-resistant. But if the grout is cement-based, sealing is highly recommended.

[Tomhanks]

Thanks! One more thing, I've recently noticed some of the grout coming off in the bathroom, but there's still grout between the tiles. It seems like it's just the excess grout, but is that normal? Also, I can see a color difference between the current grout and the previous one. Is that expected, or does it mean something went wrong? Just curious if you could shed some light on this.

[Downaski]

Yes, it’s normal for some excess grout to come off after installation, especially if it wasn’t fully wiped away during the grouting process. Sometimes, a thin layer of grout can remain on the tile edges or within the grout lines, and over time, it naturally flakes off as it loosens. As long as the grout lines themselves remain intact and aren't crumbling, there’s usually nothing to worry about.

The color difference between the new and old grout is also common and can happen for a few reasons. If the grout was mixed slightly differently or if it’s curing at a different rate, the shade may not match perfectly right away. Also, exposure to moisture, cleaning products, and daily use can cause the old grout to darken or lighten over time. If the difference is significant, it could indicate that the grout wasn’t mixed consistently or that sealing (or lack of sealing) is affecting the appearance. If you want a more uniform look, you might consider using a grout colorant or sealer to even out the color. Let me know if you need recommendations on that!

[Tomhanks]

I was just worried about whether the grout was properly installed, but that explanation makes a lot of sense. If the sealer is only for aesthetics, I’d definitely skip it. And thanks a ton, Downaski, for all the help!