Is Sealing Grout Necessary?

A man sealing the grout between floor tile.

Whether you’re tiling a bathroom or installing a kitchen backsplash, adding the grout sealing process to the project may seem like you’re prolonging an already somewhat arduous task. The sealing process may even have you wondering if you can get away with not doing it at all. Below, we get to the bottom of whether or not grout sealing is truly necessary so that you don’t have to wonder the next time one of these DIY projects arises within your home.

What Is the Purpose of Sealing Grout?

A man applying grout between gray shower tiles.

So, what’s the purpose of sealing grout, anyway? It’s actually an important part of a number of DIY projects. Primarily, sealer prevents moisture from entering the grout under tiles. Because grout is primarily made of sand (it's inexpensive and fills seams well), it's extremely porous and can absorb water, among other materials. Grout sealer prevents water from having the opportunity to penetrate between tiles by sealing the substance off and protecting it from other moisture and debris.

Keep in mind that floor tile requires sealer more urgently than wall tiling, as it typically sees more traffic (although both are likely to need sealer in general).

Is Grout Sealer Always Necessary?

Gray shower tile and sealed grout with water droplets on them.

The question on everyone’s mind: is grout sealing always necessary? The answer to that, in short, is yes. Grout sealer is necessary, almost all of the time. We’ll get into why it’s almost always necessary here and the instances where it is not actually necessary later in this article.

Grout sealer is frequently regarded as a decorative measure taken in a tiling project. However, it’s much more than an aesthetic addition. In fact, grout sealer is a structural must between tiles, securing them together by providing a hard and inflexible filler between gaps. In essence, this is a bonding agent, and it’s also a filler that prevents debris from collecting between tiles.

Since grout is so important, it’s also important that this substance is protected by a sealer. Tile is almost always in areas that are exposed to an influx of moisture—namely bathrooms and kitchens—thus, the porous substance between tiles needs to be protected from water.

A bathtub with tile that has mildew on the grout.

When moisture collects within grout, it can promote the growth of unwanted microorganisms. These include mold and mildew. Not only are these unattractive and unwanted issues within your home, but they can also be harmful to your health. Not to mention, these issues are tough to get rid of.

If you’re in doubt whether or not sealer is necessary, you can always perform a simple test. Simply take a few drops of water and dribble them along the grout in question. If the water is absorbed into the grout, it certainly needs to be sealed. If the grout resists absorption and water beads up on the grout, it already has sealer and does not need more.

Sealer is an easy way to keep moisture out of grout, maintaining the health and cleanliness of the construction material and ensuring it functions the way it was intended to.

Sealer With Epoxy-Based Grout

As mentioned above, there are instances that dictate when sealer is not completely necessary. When epoxy-based grout is used, sealer can be skipped. Although this type of grout is not quite as popular as others because it’s harder to mix and trickier to apply, it does allow for this somewhat tedious step to be skipped. This is because it’s a grout that naturally sheds water without any additives, naturally deflecting moisture and voiding the need that typically exists with grout to be sealed.

While sealing grout may sometimes feel like an unnecessary step of a tiling project, it’s actually one that reigns high in importance in almost all instances. When in doubt, take the time to seal your grout. You won’t be sorry as it will do nothing but help prolong the life of your tile job and keep your kitchen or bathroom in pristine condition.