Is It Necessary to Seal Grout? It Depends.

Published on:
Last Update:

You’ve just finished installing your new floor tiles and grouting the gaps between them. “What next?” You may ask! Well- the next step is to seal your grout lines before you can consider your newly-installed floor surface ready for use.

In this guideline, we’ll take you through the essentials of sealing grout, as well as applicable timelines.

Is It Necessary to Seal Grout?

What is the purpose of grout sealer?

Since grout is typically made of porous cement and sand, grout sealer is used to prevent it from soaking in damaging elements such as stains, moisture, and microbes. The sealer, which is waterproof, works by coating the surface to keep off the aforementioned element from coming into contact with your sanded and unsanded grout.

In doing so, grout sealer helps to maintain the sparkling appearance of your flooring. The last thing you want is an unsightly floor with unevenly-colored grout lines due to the absorption of water and food stains. What’s more, microbes/ fungal organisms like mold spores tend to make habitats out of unsealed grout. As you may be aware, the smell of mold within your house is usually unpleasant, and mold also presents a human health hazard. You can prevent mold growth on your grout by sealing it with a grout sealer. But, can I seal tiles before grouting?

Does all grout need to be sealed?

No- not all types of grout have to be sealed. Epoxy grout- for instance- is non-porous, hence negating the need for a sealant. The fact that it’s also flexile minimizes epoxy grout’s susceptibility to chips and cracks.

How to seal grout on tile floor

Once your grout has cured and dried up, you can now seal it, in accordance with the procedure outlined below:

i. Apply taping

Prepping the floor by taping off any adjacent surfaces is necessary to avoid creating a mess. For instance- if you have unsealed wooden floorboards installed, this step is mandatory, since such surfaces are porous and will soak up any grout sealer that comes into contact with them and get stained in the process.

ii. Apply Sealer

Now, use a paint brush or a paint roller to apply the grout sealer, making sure to go through every single grout line in the room. As a precautionary measure, you may want to start sealing from the farthest corner to enable you to leave without tampering with your work when done, as you don’t want to walk over the wet sealant that you’ve just applied.

The sealer should be gently applied in uniform coatings over the grout lines. Rushing over the grout lines is likely to lead in messy work and you’ll end up staining your precious tiles. This is the last thing you need, especially if you have porous, natural stone tiles installed; as they’ll absorb the grout sealer and get discolored. To prevent this from happening, ensure to immediately wipe off any grout sealer spills on the tiles as soon as it happens.

iii. Apply another Coat of Sealer

After applying the initial coating of grout sealer, give it about 10-15 minutes to seep into the grout. Take note- however- that this waiting duration varies depending on the brand of sealer that you’re using. You should- therefore- check the product label for manufacturer’s recommendations on waiting times. Then, apply the second sealer coating using the same process that you used to apply the first one.

iv. Remove Excess Sealer

After waiting for the second sealer coating to stick in, ensure that you wipe off any excess sealer left on the surface of the grout lines. This can be done using a dry, clean mop or a dry piece of cloth. In addition, you should ensure to remove any sealer residue left atop the tiles by using water and a scouring pad.

v. Give the Sealant time to Cure

Once you’re done- it should normally take between one-two days for the sealer to cure. During this time, you should avoid using the bathroom if the installation and sealing was done there as well. Also, as a safety precaution, keep your pets from the surface as they may step on the wet sealer and then lick their paws. However, you can always walk on the floor surface as soon as four hours post-installation, as this won’t affect the sealer’s curing process.

How long should you wait before sealing grout?

Never attempt to seal your tile grout immediately after applying it, as you need to give it enough time to cure and dry up. Sealing your grout before it’s dry can lead to cracks in the grout. The recommended waiting time is usually anywhere between 48-72 hours.

How often should you seal grout?

Ensure to re-seal your grout at least once a year, as the old sealant is likely to wear down in various parts within that time period, depending on foot traffic within the house. However- for rooms that aren’t used that frequently like the bathroom- you can re-seal the grout lines every couple years; as the sealant takes longer to wear out in such areas.

If in doubt whether your grout needs a new sealer coating, you can always use the water-test; whereby you spray water onto the surface of the grout and take mote of what happens next. If the water beads up on the surface of the grout lines, then your sealant is still intact. If it however soaks in/ drains into the grout, it means your old sealer has been worn down and it’s time to re-seal. Alternatively, you can always contract the services of a professional tile setter to determine whether resealing is necessary, depending on the type of grout you have installed and its quality.

Sources and References

NATCO (National American Tile Cleaning): Properly Sealing Grout Will Keep It From Becoming Dirty And Stained.

Photo of author


Joe McGuinty
I’ve been working with floors for over 12 years. I started as a flooring contractor, primarily in materials selection. Then, I switched careers into accounting, so my wife and I began buying, renovating, and re-selling homes on the side. You’d be surprised how much value you can add to a home simply by adding new floors.

Leave a Comment