After you invest in a bathroom remodel, complete with new tile, the last thing you want to do is fail to care for your investment. If you want tiles and grout to last for the long haul, then you may need to apply a sealer.
Tiles made from glossy materials like glass and glazed ceramic tiles don’t need to be sealed, while unglazed tiles and natural stone tiles do need to be sealed. The grout that runs between your tiles to hold them in place almost always needs to be sealed as well.
Let’s clear up which types of bathroom tiles and grouts need to be sealed in order to resist damage from mold or cleaning agents.
TILE GROUT SEAL Porous, Unglazed Tile Cement & Sand Grout DON'T SEAL Glossy, Glazed Tile Epoxy-Based Grout (Sealing is Optional)
Are Bathroom Tiles Waterproof?
Technically, no tiles are 100% waterproof. If you have water sitting on them long enough, it will eventually penetrate the tile causing issues, but let’s put that to one side.
Generally speaking, any tile that has a glossy finish or is glazed ceramic or glazed porcelain (a type of ceramic) should be waterproof enough for a bathroom.
Glazed tiles are covered with a thin layer of liquified glass. This is what makes them naturally moisture-resistant.
While most glazed tiles don’t require sealer, there are some exceptions so always check the manufacturer’s instructions.
And keep in mind that just because your bathroom tile doesn’t require sealer, you’ll still need to seal the grout between your tile.
Unglazed tiles and natural stone tiles are not waterproof at all. If you do not seal these tiles, they’ll grow bacteria. You can end up with damaged tiles, mold issues, and your bathroom won’t look as beautiful as you’d hoped. For more detail about which bathroom tiles are waterproof, read this post.
To learn more about tile finishes and which ones are most water-resistant, read 13 Tile Finishes to Make Your Bathroom Design Pop!
Steps to Seal Bathroom Tiles
If you are doing a bathroom remodel, replace your tiles first. Next, seal them, and then apply grout, in that order. (Be sure to check out our guide to how to DIY bathroom tile installation.)
1. Buy the Sealer
Sealers will always impact the look of your tiles, even if just a tiny bit. This is because you are adding an extra layer on top of the tile material.
There are two types of sealers you can purchase for titles:
Penetrating Sealers – This type of sealer is absorbed straight into porous tiles. It can have a very slight impact on the color, but this is the more common type of tile sealer to use.
Color Enhancing Sealers – This type of sealer is designed to enhance the color or finish of the tile, so it will definitely change the appearance.
When you are searching for a sealer, there are a couple of things to remember. First, all sealers will list the types of tiles they will work with. If your tile material is not listed, don’t use that sealer.
Second, buy a small bottle of sealer first. Use it on an old bit of tile or something hidden. Take a look at how it impacts the color of your tile. If you aren’t a fan, buy a different sealer.
2. Clean and Dry the Tile and Grout
Before you apply any sealer, make sure the area is completely clean and dry. This is really important so that you don’t seal moisture into your tiles and start a mold problem.
3. Apply Sealant (Usually Two coats) and Let Dry
All sealers are applied in different ways, so pay attention to the manufacturer’s instructions.
Most will require that you apply two different coats to the surface. You will put the first coat on, wait for it to dry, and apply the second. It can often take several hours for the drying process, particularly if you have very absorbent tiles.
4. Wipe Away Excess
As you work, wipe away any excess sealer that isn’t absorbed by the tiles.
After the sealer dries, if you see there are different shades of color on your tiles (i.e. some parts have absorbed more sealer than others), you may need to rectify this by applying additional sealer to small areas. Turn on bright lights to help you inspect.
Only after the tile is completely sealed should you begin to seal the grout.
Grout v Caulk: What’s the Difference?
The material that runs in lines between your tiles is either called “grout” or “caulk”. Most bathrooms will use both because while they are made from similar substances, each is used for a different purpose.
What Is Grout?
Most grout will be a mixture of cement, sand, and water. Grout is incredibly tough, and it is put between the tiles.
What Is Caulk?
Caulk is a flexible plastic-based adhesive. It is waterproof, and it will often be used in the bathroom in areas that come into a lot of contact with water.
For example, you are going to see caulk used around the perimeter of the bathtub. You may also see it used around pipes. In some cases, caulk can even be used as an adhesive.
It is important to know whether you are looking at caulk or grout because you don’t need to seal caulk but you usually do need to seal grout.
Is Bathroom Grout Waterproof?
Bathroom grout is moisture-proof. It can put up with a small amount of water, and perhaps the steam coming from your shower or bath.
But remember, grout is just sand and cement. It is incredibly porous. This means it has loads of tiny little holes that will allow water to get through.
If you don’t seal it, then the water can get under your bathroom tiles. This can cause the tiles to break off of the wall, and bathroom mold or mildew can start to form in the walls.
Basically, if you just put bathroom grout up there behind and between your tiles, you are just asking for trouble. It won’t be long before you need to pull those tiles off of the walls.
The one case where you don’t absolutely have to seal the bathroom grout is if you are using an epoxy-based grout.
Still, because sealing grout is such a simple process, even if you do have an epoxy-based grout, it wouldn’t hurt to add another layer of protection.
How To Seal Bathroom Grout
Sealing grout in your bathroom is surprisingly easy, and there are products available that will help speed up the process.
If you have an unglazed tile, then you need to be extremely careful with this step. Unless you wipe it off immediately, any grout sealer that gets on an unglazed tile can soak in and discolor your tile.
Also, be sure to let new grout thoroughly dry for 48-72 hours before applying any sealer.
You have three options when it comes to applying bathroom grout sealer:
With a brush-on sealer, you literally just paint the sealer onto the grout. The grout will then absorb the sealer, and it should be properly protected.
If you have ever painted with a small paintbrush, then you know just how long this will take. You probably won’t be able to use your bathroom much during this time either, because you have unsealed grout everywhere.
See this grout and granite penetrating sealer from The Floor Guys on Amazon.
How cool is this? You can change the color of your grout and cover it with a waterproof seal at the same time? These Grout Pens come in a variety of colors from gray to beige to white and with either a wide or narrow tip. Very inexpensive, too.
Spray-on sealer is the quickest way to apply sealer.
The one thing that you will need to take care of here will be unglazed tiles. When you are spraying, you will get some sealer onto the tiles.
If you don’t want those tiles to absorb the sealer, then you are going to need to rub it off right away.
Should You Seal Bathroom Tiles and Grout?
Most bathroom tiles and grout need to be sealed. The only tiles that usually do not need to be sealed are ceramic and glazed tiles (including most porcelain tiles).
Always check with the manufacturer for guidance because there are some exceptions.
You will almost certainly need to seal the grout between these tiles (unless you are using an epoxy grout).
You will have caulk in your bathroom, but since this is waterproof anyway, it shouldn’t need to be sealed. However, you will want to keep an eye on it. Caulk can crack over time and will need to be replaced. (See my guide to fixing cracked bathroom caulk.)
Remember, sealer doesn’t last forever. There will be times when you will need to completely reseal your bathroom although, hopefully, that won’t be until several years down the line.
For everything you possibly need to know, read 21 Tips for Perfect Bathroom Tile. This ultimate guide resource tells you everything about bathroom tile materials, colors, sizes, waterproofing, and much, much more.