Is Tile Grout Waterproof?(Solved)

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Is Tile Grout Waterproof?

No! Tile grout is not waterproof but water-resistant. Tile grout boasts a mixture of cement, sand, and water, which is naturally porous. This means it can absorb water and potentially allow moisture to seep through.

To make grout more water-resistant or waterproof, you can use epoxy or modified cement-based grout. This is a type of grout that boasts high resistance to water and stains.

It’s made of epoxy resins and hardeners, which provide excellent waterproofing properties. Modified cement-based grouts, on the other hand, contain additives that enhance their water resistance.

This being said, grout does not offer a 100% guarantee of complete waterproofing from water absorption. For example, if the joints between adjacent tiles are not properly sealed, water might seep through them.

The best way to know whether your tile grout is waterproof is to check on it periodically. If you notice moisture under the tiles, the grout may have failed in waterproofing them.

For added protection against water, you can seal grout joints before setting the tiles in place.

Tip: I cannot stress the importance of cleaning tile grout. When the grout is dirty and full of dirt, it becomes more susceptible to absorbing water.

Can Water Go Through Tile Grout?

Tile grout is a mixture of cement, sand, and quartz powder. You can use the material in the interior or exterior of a building. Tile grout is a mixture of cement, sand, and quartz powder that boasts visibility in the interior or exterior of a building.

Yes! Water can go through tile grout in some instances, such as:

1. Crack in Grout

If a crack is present in the grout, water may penetrate through the cracks and into the tile. This can lead to extensive damage if left untreated.

2. Holes in Tile

Holes or cracks in tile can allow water to penetrate the grout and damage the tile. You must repair the damage immediately if any holes are in your tile.

3. Leaks in the Tile

If water leaks into the tile from the drain pipe, it can make its way through the tile’s grout and slowly dampen the entire floor. This is a major problem that needs to be repaired immediately.

4. Leak in the Pipe

When you have a leaking pipe, water will come through the grout and into the tile. Examine the entire floor for this type of damage.

5. Damage to the Flooring

If there are any tile cracks in your floor, chances is that water will be able to move through. You need to be careful about stepping on tile because you may fall through it and puncture the membrane of your sub-flooring.

6. Expansion Joints

If your tile grout is made of cement, you will notice expansion joints in the grout. If water enters the joint and damages the flooring, you should repair it immediately.

7. Waterproof Caulking

Waterproof caulk can also allow water to penetrate through the grout and into your floor. This can cause mold to grow on your floor or even lead to structural damage in your home.

Tighten these joints as soon as possible to stop this from happening again.

Do You Need to Waterproof The Tile Grout?

No! You don’t need to waterproof your tile grout because it boasts water-resistance properties. Yet, grout is porous and can absorb moisture.

Therefore, applying a grout sealer can provide an added layer of protection in certain situations, such as in areas with excessive water exposure or with a higher risk of moisture damage.

If you need to waterproof grout, choose your sealer carefully. Many sealers are incompatible with grout and can cause discoloration or mold development.

Before applying a grout sealer, it’s advisable to test it on an inconspicuous tile area. For example, if water-resistant or epoxy-based grout is used, allow sufficient time to dry before applying sealant.

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To ensure the bond between the sealer and grout is tight, you must allow time for the sealant to cure.

Ultimately, whether you choose to waterproof your tile grout depends on factors such as the type of grout, the location of the tiles (e.g., bathroom, kitchen, outdoor), and your preferences for maintenance and longevity of the grout appearance.

For best results, always allow your tile to dry thoroughly. Additionally, following the grout-sealing instructions included in the container is vital.

Before applying a sealer, always test the sealer on an inconspicuous area. This will ensure that the sealer can adequately adhere to your grout and fully cure before application of your tile.

Avoid applying sealer when the grout lines are still damp.

What Can I Mix with Grout to Make It Waterproof?

Latex Additives-Water repellant.
– The product also helps seal grout joints.
– Additive removable with mineral spirits or hydrochloric acid.
Silicone-Based Grout Sealers-Provide a waterproof seal that is resistant to mildew and mold.
Epoxy Toughness-Waterproof.
– Provide a longer-lasting seal.
– No initial odor.
– Rarely have to be removed.
Silica Fume-Increases grout density.
– Enables the grout to be more abrasion resistant.
– Water absorbent.
– Reduces water absorption.
– Does not change the appearance of the grout.
– Long-lasting.
– Able to be removed with water and a mild detergent.

What Happens If Water Gets On The Grout?

Seep into the Seal-Deteriorate.
– Result in water stains.
Cement may lose its Strength-Result in a leaky grout joint.
Grout may Discolor-Deteriorate, fade, or turn yellow.
Water Leak-Result in potential mold.
– Result in potential mildew because of the moisture.
Damage to other Materials-Damage to flooring, the integrity of water-resistant materials.
Potential Health risks-Risks include skin irritation -Rash -Infection with E. coli.

Why Is My Grout Coming Off When Wet?

1. Poor Installation

Your grout may be coming off when wet because it was not installed correctly in the first place. If your grout is cracking and popping when you install it, this could be the problem.

2. Varying Materials

If you use different materials on your floor, the grout may separate because they must match up better. Larger grout areas will be affected if you have different colors or materials.

For example, if you have white grout and it’s very noticeable, then you should try to eliminate it as much as possible. White grouts do not match with any colors and can look blotchy when installed.

3. Insufficient Curing Time

This is a common reason your grout cracks and pops when wet. You should purchase a high-quality water sealer or glaze to cure your grout. This will ensure you are getting a good seal.

4. Water Seepage

You may have cracks in your grout. The water will go through these cracks, and when the grout dries, it may come off. You should seal it to prevent this from happening.

5. Excessive or Poor Curing of sealer

The sealer you use must be dry before you remove the paper that is protecting it. You should also let this sit for 24 hours before installation. Otherwise, it may come off later on when it is being used.

Why Is the Grout Cracking on My Floor Tiles?

1. Insufficient Grout Mix

Correct proportions of grout mix during installation can result in strong grout prone to cracking and crumbling.

2. Floor, Not Level

If the floor isn’t level, grout can get pushed up and around the edges of tiles, causing a hole in the surface.

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3. Grout Not Properly Hardened

Improperly hardened grouts are more likely to crack and crumble as they age, especially if exposed to high humidity or salt corrosion in a pool area or other similar locations where water is present over long periods.

4. Tile Set Uneven

When tiles are not laid on a flat surface, you will see a noticeable pattern of cracks forming over the tile. You can correct this with wet grout leveling.

5. Stacking Heavy Objects On Grout Lines

Egg crates, shelving, and other objects placed on grout lines put pressure on the grout that can cause it to crack and crumble.

6. Loose Grout Joints

Loose grout joints make it easier for air to get in and let water seep through, resulting in the grout cracking and crumbling.

7. Improper Grout Joint Taps

There is a difference between the way you tap a hole and the way you tap a joint. Always allow the proper amount of threading and full penetrating power into the holes.

Also, ensure the threads are pinched off quickly, leaving little indentations in the tiles.

How Do You Know If The Grout Is Damaged?

Discoloration-Darker, lighter.
-Noticeable stains due to dirt, mold, or water damage.
Cracks/ Missing Sections-Examine the edges for cracks or missing sections.
-If the grout does not overlap, it is most likely damaged.
Mold Or Mildew Growth-Noticeable dark spots that grow on the grout’s surface.
-Mold is often noticed in bathroom or tile, kitchen, and laundry areas.
Water Stains-Bathroom or kitchen areas.
-Walls/ ceilings
Soft/Spongy Texture-Excessive water absorption.
-Possible structural damage.
Increased Water Absorption-Loss of sealing properties.
-Potential damage.

Why Does Grout Absorb Water?

1. Porous Grout

When water seeps into porous grout, it gets absorbed by the solid particles. This is because the water molecules are small enough to fit between the particles, and as a result, it gets absorbed by the grout.

2. Cohesion

When the water is pulled into the grout, it will try to spread out, and this causes the grout to shrink on the opposite side of the water. This effect is due to cohesion.

3. Capillary Action: The porous nature of grout allows water to be drawn into it through capillary action. Capillary action is the ability of a liquid to flow through narrow spaces, such as the tiny channels or capillaries within the grout.

Water molecules are attracted to the surfaces of the capillaries and can move upward against gravity, causing the grout to absorb water.

Is Tile Grout Waterproof?

4. Cementitious Properties: Grout contains cement, which goes through a chemical reaction called hydration when mixed with water. During hydration, the cement particles react and form a crystalline structure.

However, only some water in the grout mixture is consumed during hydration. Some of it remains in the structure as capillary water or entrapped water.

The capillary water is trapped within the cement’s crystalline structure and cannot move. It becomes available for absorption when the grout becomes soaked with water. This excess water is referred to as entrapped water.

5. Absorption By Sand Particles: Grout also contains sand with its porosity. The sand particles can absorb water through capillary action and retain moisture within the grout structure.

6. Absorption By Cement Particles: Cement particles absorb water when they are hydrated and form a sponge-like structure that holds water within the structure.

What Are The Disadvantages Of Grouting Tiles?

Weaker Bond-Increased risk of cracking.
-Water absorption.
-More difficult to remove the old grout.
Color Variation-Dirt and debris settling into the grout.
-Increased risk of staining.
Uneven Surface-Cracked grout.
-Gaps between tiles.
Layering Effect-Increased risk of cracking.
-Difference in texture.
Compromising Long-Term Durability-Weaker bonding.
-More difficult to remove the old grout.
-Increased risk of staining.
Stain Palette Variation-Dirt and debris settling into the grout.
-Cracked grout and gaps between tiles, different stain colors.

What Happens If You Put Grout On Top Of The Grout?

1. Strengthen The Surface To Increase Water Resistance

Grout is porous and weak, especially in a tile’s thin layers. Applying grout on top of the grout weakens the surface and may cause leaking.

2. Strengthen The Grout

Applying a thick layer of joint compound or mastic can create an impermeable film that is strong enough to support additional layers of grout.

3. Apply A Waterproof Epoxy

Although this method is costly, it is the most effective way to waterproof grout. To apply, mix epoxy with acrylic powder and water to fill in the grout’s pores. After it dries, you can use additional layers of grout.

4. Eliminate The Need For Waterproofing

A sealing solution will harden between tiles, eliminating the need for waterproofing over grout. However, these solutions can discolor and create a sticky surface that may be challenging to remove.

5. Change Colors On One Side Without Working The Grout Around

This is the mostly used method for tinting grout, but it can also be helpful for cleaning. Apply, clean, and dry a tile. Apply enamel on one side of the tile and wait 3 hours.

Clean off with a stiff brush, then wait another 3 hours to ensure color has settled in the pores. When the first coat has thoroughly dried, buff it with a soft cloth to reveal a different color on the other side of the tile.

6. Clean Tile Grout Without Removing It

The grout lines can get repaired using a damp sponge and cleaning solution. This solution will work the grout up and make removing it easier, especially for small areas.


Tile grout provides a unique look to your floors, adding life and style to your home. It can be an opportunity to improve the visual appeal of your house in some ways while at the same time increasing durability. 


Hi! I I faced many questions from customers about different products, and there was hardly any help on the internet. After learning all the things about these products as a manager the hard way, I decided to start a blog and help other people.

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