Grout is a workable paste that fills the gaps between floor and wall tiles.  It’s usually made of a powdered mix of water, cement, sand, and color pigment, which hardens after being left to cure.  You can find tiles almost anywhere in the house, but not all types of grout can withstand areas prone to getting wet.

Traditional grout is porous since it has tiny pores which can absorb liquid.  Constant exposure to moisture can soften the grout, causing it to crumble or deteriorate.  Epoxy grout is non-porous, which means it is waterproof and more suitable for bathrooms or areas that often get damp. 

This article will dive deep into your home’s best tile bonding and sealing solutions. Read on to learn more about the different grout types and which ones are waterproof.

Which Types of Grout Are Waterproof?

Once your tiles have been set, grout is necessary to give them the finishing touch. However, aside from aesthetic reasons, there are many advantages to using grout in tiles.

No matter how neatly laid out your tiles are, gaps are inevitable. Grout fills the spaces between the tiles, which serves the following benefits:

  • Grout keeps dirt and debris from getting lodged around the tiles.
  • It protects the edges of the tiles and keeps them from chipping and cracking.
  • It strengthens and adds rigidity to your floor and walls.

You can use tiles on any flat and stable surface. Given their durability, ease of maintenance, and vast design options, you shouldn’t be surprised to find tiles in numerous areas of a typical home.  But since some areas in the house are prone to moisture, it helps to know which types of grout are waterproof and which ones aren’t.

Cement-Based Grout

Cement-based grout consists of tiny grains mixed with water to form a paste-like substance. Out of all the grouts, it is the easiest to work with and install because you can keep adding water as it hardens. Curing time for cement-based grout is relatively quick since you can walk on it after 24 hours.

Due to its composition and convenience, cement-based grout is the cheapest to purchase and install.

The downside with using cement-based grout is that even after it stiffens and dries, it’s left with many tiny pores that make it porous. Dirt and moisture can make their way into the little holes, which eventually lead to mildew or stains between the tiles. 

Despite its drawbacks, the affordability of cement-based grout still makes it a popular choice, particularly for rooms that are not prone to spills and moisture. Cement-based grout can either be sanded or sanded.

Sanded Grout

Sanded grout is cement-based, and as the name suggests, it contains sand. The sand particles give it added strength, making it ideal for grout thicker grout lines ranging from ⅛ of an inch to 1 inch.

If you’re tiling floors with heavy foot traffic, sanded grout is a smart option since it is affordable and durable. 

Premium Sanded Grout

The next type of grout available in the market is referred to as premium sand grout. This grout is similar to sanded grout. However, it consists of much finer sand particles which makes it ideal for use on grout lines that are twice as narrow. 

Unsanded Grout

Unsanded grout is essentially sanded grout without the sand. The absence of sand particles gives a smoother texture, making it non-abrasive and less prone to scratching delicate surfaces like glass and ceramic tiles. 

If your grout lines are less than ⅛ of an inch, or if you’re working with smaller tiles, you should use unsanded grout since it can flow through tight spaces.

Still, one disadvantage of unsanded grout is it’s not as durable as sanded grout since it tends to shrink when it dries.

Acrylic Grout

Acrylic grout consists of unsanded grout with latex and acrylic polymer additives that comes premixed and ready to use. Yet, as convenient as it is to use straight from the container, acrylic grout should be applied in small portions since it cures a lot faster. 

You should also clean any residue from tiles within twenty minutes because it can be rather difficult to remove once it dries.

Acrylic grout is stain and water-resistant, so it will not discolor or accumulate mold and mildew. Its unsanded quality is ideal for use on marble or ceramic tiles, although it can still scratch stainless steel. 

Another advantage of acrylic grout is that it has a certain degree of flexibility, making it suitable for wet areas that bear heavy foot traffic. And since it comes ready to use, it takes significantly less time to install.

Epoxy Grout

Epoxy grout is made of epoxy resins and filler powder, making it waterproof and highly stain resistant. If durability is a priority for you, epoxy grout is ideal since it doesn’t crack, shrink, or discolor.

The toughness of epoxy grout allows it to withstand water and chemicals, making it ideal for industrial and commercial applications, as well as kitchens and bathrooms.

One of the most significant drawbacks of epoxy grout is that it is more expensive and difficult to install. Epoxy grout hardens pretty quickly, so it has to be applied in small portions. Additionally, installing epoxy grout requires skill and takes more time.


The table below summarizes the different types of grout and their pros and cons.

 Sanded GroutUnsanded GroutAcrylic GroutEpoxy Grout
PorosityPorousPorousWater resistantWaterproof
Recommended grout lines⅛ inch to 1 inchLess than ⅛ inchLess than ½ an inchLarge grout lines
Curing Time Before Walking24 hours24 hours72 hours48 hours
ProsAffordable   Durable   Easy to installWill not scratch delicate surfaces
Ideal for narrow grout lines
Easier to apply on vertical walls
Water and stain resistant
Easy to install
Comes premixed
Cheaper than epoxy grout
Withstands chemicals
Extremely stain resistant
Does not discolor
No sealer required
ConsProne to discoloration
Prone to discoloration, cracking and shrinking
Difficult to clean once dry
Not as waterproof as epoxy
More expensive than cement-based grouts
Difficult to clean

You might also want to read: How Long Does Grout Take to Dry?

Sealers Protect Your Grout From Water

Since some grouts are porous, you can apply sealers to give the grout protection from water and stains while adding strength and durability. The caveat is that applying grout sealer will not make your tiles foolproof because water and dirt can still seep through any cracks or holes in the tiles.

In any case, many experts will recommend applying a sealer once the grout has completely dried. A sealer will also serve as an added layer of protection that will ward off the growth of mold and mildew. It also prevents the build-up of water and grime that can eventually damage your tiles.

You can also use grout sealers to fill gaps and cracks or cover dirty stains on your existing grout. I recommend the PECTRO Grout Sealant. It comes with a repair kit that allows you to use it on various grout lines.

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Will Sealer Work on All Types of Grout?

Sealer won’t work on all types of grout. It’s ideal for cement-based grouts due to their porous quality but epoxy grout is waterproof and won’t benefit from a sealer – sealer will cause it to turn yellow. Acrylic grout is water resistant, but manufacturers recommend applying sealer once it’s dry.

Penetrating and Non-Penetrating Grout Sealers

Grout sealers come in the penetrating and non-penetrating variety. The difference between the two types of sealers is that penetrating sealers enter the grout and fill the holes, while non-penetrating sealers simply form a protective layer on top of the grout. 

Penetrating sealers fill the tiny pores and provide resistance to moisture without suffocating the grout. Cement-based tiles situated in bathrooms, kitchens, or areas that get wet should use penetrating sealers.

Non-penetrating sealers, on the other hand, serve as an extra coating for the grout. However,  they aren’t completely waterproof and can trap water penetrating the tiles or grout by keeping it from evaporating.   

Chemically and Naturally Formulated Grout Sealers

Sealers with a chemical composition generally do a better job penetrating the grout and acting as a seal to prevent moisture from passing through. Such sealers are incredibly durable and can last decades before a reapplication is needed.

Other types of sealers are made with natural oils, which the grout absorbs to make it water resistant. These sealers are more environmentally friendly and less harmful to people. However, they are not as durable as chemically formulated sealers and must be reapplied more often. 

Final Thoughts

When installing tiles, selecting the correct type of grout depends on:

  • The tiles
  • Spacing
  • Surrounding environment.

Some tile grouts are porous and unsuitable for areas prone to dampness. However, using waterproof grout in every room is impractical since it’s expensive.

Sanded grout is best for dry areas, while unsanded grout is suitable for delicate tiles and thinner grout lines. Cement-based grout is porous, but applying grout sealers can prevent moisture and dirt build-up that could damage tiles.

For kitchens, acrylic or epoxy grout is best since they are non-porous. They’re pricier, but their durability may end up saving you money.

See also: Groutless Tiles: Types, Installation, and More

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