Epoxy Grout: Types, Features, Applications, Cleaning, Pros and Cons

Written By Adam Paul - Waterproofing Expert

Epoxy grout is a grout that is used to fill the gaps between tiles and stones in various construction projects. Epoxy grout consists of epoxy resin and hardener. Its strength and stability are higher than the regular cement grout. Therefore, it is highly waterproof, has stain resistance, has less shrinkage, is crackable, and is durable. Due to these characteristics, epoxy grouts can be used on bricks, cement-based precast terrazzo, porcelain, glass tiles, marbles, natural stones, ceramics, mosaic, quarries, and cement-based tiles.

Epoxy grouts are mainly two types according to their particle sizes. Those are sanded and unsanded epoxy grouts. The recommended ANSI strength of the epoxy should be more than 3500 psi, and shrinkage should be less than 0.25%. A properly installed epoxy grout can withstand 15-20 years with proper maintenance and repairs. The lower-strength epoxy types can be used for tile works, while higher-strength epoxy grouts can be used for extremely higher-performance tasks.

You should follow the proper step-by-step guide while applying epoxy grout, such as preparing the surface before applying epoxy grout, mixing the epoxy hardener and resing together, applying the grout on the substrate, cleaning the excess epoxy on the surface, protecting the epoxy grout using sealants and sealing the epoxy to increase the further resistance on the surface.

You can clean the epoxy grout by using mild cleaners, scrubbing, and deep cleaning. You should not use harsh chemicals to clean the epoxy grout because that can harm the grout lines. The pros of epoxy are higher durability, stain resistance, strength, consistency in color, and higher flexibility than regular grouts. As cons of the epoxy grouts, they are more complex to install, consist of limited working time, difficult to remove, are hazardous to the user and have a higher cost to install.

Epoxy grout can be damaged due to heavy impact, using an abrasion cleaner, exposure to chemicals, exposure to excessive water, and sudden temperature fluctuations in the area. The most used epoxy grout brands are Laticrete, Mapei, Custom Building Products, TEC, Ardex, Schluter Systema, and Bostik.

You should not use epoxy waterproofing epoxy grout when the substrate is not stable, exterior, and exposed to extreme weather conditions, expansion joints, and natural stones. These can loosen the bond with the substrate or crack the epoxy grout over time. Epoxy is a highly waterproof material. Hence, it can be used as a waterproof material for construction purposes.

Is Epoxy Grout Waterproof?

Yes, epoxy grout is highly waterproof. Epoxy grout is non-porous and resistant to moisture penetration unlike regular cement grouts. This inherent waterproofing ability makes epoxy grout an excellent choice for use in wet areas such as showers, bathrooms, kitchens, swimming pools, and other areas prone to moisture exposure.

The waterproof nature of epoxy grout helps prevent water from seeping into the grout joints and underlying substrate, which can lead to mold growth, mildew, staining, and structural damage over time. Epoxy grout repels water, it is easier to clean and maintain than cement-based grout, which can become stained or discolored when exposed to moisture.

What is Epoxy Grout?

Epoxy grout is a type of grout that is used to fill the gaps between tiles and stones in various construction and tiling projects. According to the American National Standards Institute (ANSI) A108.3 and A118.6 sections, Epoxy grouts should consist of a compression strength of more than 3500 psi, tensile strength of more than 2000 psi, and shrinkage less than 0.25%. It should be suitable to fill the joints between 1/16” to 3/8” (1.5 mm to 10 mm).

Epoxy grouts are made from epoxy resin and a filler powder. These are highly waterproof, stain resistant, less shrinkage, crackable crumble, and more durable than regular cement grouts. Therefore, epoxy grouts can be used for brick and thin bricks, cement-based precast terrazzos, impervious porcelain and glass tiles, marbles, natural stones, ceramic, mosaic, quarry, and cement body tiles which are used in constructions.

Hence, Epoxy grouts can be used mostly on bathroom floor waterproofing, bathroom wall waterproofing and kitchen countertop waterproofing.

What are the Types of Epoxy Grout?

Epoxy grouts are mainly two types according to their particle size variation.

Those two main types of epoxy grouts are

1. Sanded epoxy grout
2. Unsanded epoxy grouts

Sanded Epoxy Grout

Sanded epoxy grout contains fine sand particles mixed with the epoxy resin and filler powder. Sanded epoxy grout is commonly used for wider grout joints, typically ranging from 1/8 inch (3 mm) to 1/2 inch (13 mm) or more. The sand helps improve the strength and stability of the grout and provides better resistance to cracking.

Unsanded Epoxy Grout

Unsanded epoxy grout does not contain sand particles and has a smoother texture compared to sanded epoxy grout. It is used for narrower grout joints, typically less than 1/8 inch (3 mm) wide. Unsanded epoxy grout is suitable for use with delicate or polished tiles where the presence of sand particles might cause scratching or damage.

What is the Strength of Epoxy Grout?

According to the American National Standards Institute (ANSI), epoxy grout should consist of two main strengths: compression strength and tensile adhesion strength. The recommended compressive strength of the epoxy grout should be more than 3500 psi and the tensile adhesion strength of the epoxy grout is more than 1000 psi.

Current epoxy grout products contain more than 8000 psi compressive strength (higher than the regular grout compressive strength of 5000 psi) and tensile adhesion strength more than 3000 psi (higher than the regular cement grout tensile adhesion strength of 1000 psi)

Due to these higher strengths epoxy grouts withstand a long time with higher boning with the substrates.

What is the Lifespan of Epoxy Grout?

The lifespan of the Epoxy grout can vary depending on factors such as installation quality, environmental conditions, maintenance practices, and the specific type of epoxy grout used on the substrate. A properly installed and maintained epoxy grout can last 15-20 years or more in residential and commercial applications.

Epoxy grouts are highly durable and resistant to stains, chemicals, moisture, and cracking. These higher resistances contribute to its long lifespan. The nonporosity of the epoxy grouts prevents the growth of mold, mildew, and bacteria, further extending its longevity.

In order to maximize the lifespan of the epoxy grout, you should follow the proper and recommended manufacturer guidelines for installation and maintenance. You should apply recommended periodic resealing and applications during the installation recommended by the manufacturer.

Where Can You Use Epoxy Grout?

Epoxy grouts are two types according to their strength. Those are lower-strength and higher-strength grouts. Lower-strength epoxy grouts can be used on brick masonry, cement backer board, cement mortar beds, cement terrazzo, ceramic tiles, concrete, exterior grade plywood, gypsum drywalls, and gypsum mortar beds.

The higher-strength epoxy grouts can be used for extremely higher-performance tasks such as anchor bolts and sleeves, supporting pumps, mill tables, crushers, crane rails, engines, compressors, rotary equipment, and other heavy machinery requiring a stable and energy-absorbing base subject to dynamic loads to maintain precision alignment.

How to Apply Epoxy Grout?

You should follow the below 6 step by step method when applying epoxy grout on the substrate.

1. Prepare the surface before applying epoxy grout
2. Mix the epoxy hardener and resin together
3. Apply the epoxy grout on the substrate
4. Clean the excess epoxy grout residues on the surface
5. Protect the epoxy grout
6. Seal the epoxy grout after 3 days

1. Prepare the Surface Before Apply Epoxy Grout

1. You should clean the tile surface thoroughly to remove any dust, debris, or residues (oil, grease, wax, old paint, sealers, and curing compounds) that could interfere with adhesion.
2. Maintain the substrate temperature between 50°F and 95°F (10°C and 35°C).
3. Grout joints must be clean and free of standing water, dust, dirt or any foreign material.
4. Protect adjacent surfaces, such as countertops or cabinets, with masking tape or plastic sheeting to prevent epoxy grout from staining them.

2. Mix the Epoxy Hardener and Resin Together

1. You should follow the manufacturer's instructions to mix the epoxy grout components: resin and hardener.
2. Mix the two components thoroughly using a clean mixing container and a drill with a mixing paddle attachment. Ensure that there are no streaks or unmixed portions.

3. Apply the Epoxy Grout on the Substrate

1. Maintain the substrate temperature between 50°F and 95°F (10°C and 35°C) while applying the epoxy grout on the substrate.
2. Use a rubber grout float or epoxy grout float, and spread the mixed epoxy grout diagonally across the tile surface, pressing it into the grout joints firmly.
3. Work in small sections to ensure that the epoxy grout does not begin to set before you can clean the excess off the tile surface.
4. Use the edge of the float to scrape off excess grout from the tile surface, holding the float at a 45-degree angle to the tiles.
5. Let the epoxy grout cure about 24-36 hours

4. Clean the Excess Epoxy Grout Residues on the Surface

1. Once the epoxy grout begins to set but is still slightly pliable, use a damp sponge or cloth to clean the excess grout from the tile surface. Rinse the sponge frequently in clean water to prevent smearing grout residue onto the tiles.
2. After initial cleanup, allow the epoxy grout to cure according to the manufacturer's instructions. This typically involves waiting for a specific amount of time before performing final cleanup.

5. Protect the Epoxy Grout

1. You should protect the epoxy grout layer without any force for about 24 hours.
2. You should not allow any traffic on the epoxy grout layer at least 48 hours.
3. Do not immerse in the water less than 10 days.

6. Seal the Epoxy Grout after 3 Days

You should seal the epoxy grout after 3 days using a manufacture recommended sealer.

How to Clean Epoxy Grout?

You can clean the epoxy grout using the below 4 methods

1. Cleaning epoxy grout using mild cleaners: For the regular cleaning you should use a mild pH-neutral cleaner or a specially formulated epoxy grout cleaner. Avoid harsh chemicals or acidic cleaners, as they can damage the epoxy grout.
2. Cleaning the epoxy grout using scrubbing: If the grout lines are dirty or stained you should use a soft-bristled brush or a grout brush to scrub grout lines gently. Avoid using abrasive scrubbers or steel wool, as they can scratch the epoxy grout or tile surface.
3. Deep cleaning the epoxy grout: You should use a stronger cleaner or a commercial epoxy grout cleaner if there is a tougher stain or build up grime on the grout lines.
4. Rinsing the epoxy grout lines: You should rinse the tiled surface thoroughly with clean water to remove any residue from the cleaner.

What are the Pros and Cons of Epoxy Grout?

Pros of the Epoxy grouts

1. Higher durability: Epoxy grout is highly durable and resistant to stains, chemicals, water, and cracking. Hence, it can be used in high-traffic areas and environments with moisture.
2. Higher stain resistance: Epoxy grouts are highly stain resistant due to its non-porous nature. Therefore, cleaning epoxy grout is easy.
3. Higher strength: Epoxy grout is exceptionally strong and can withstand heavy loads and stresses without cracking or crumbling.
4. Consistent color: Epoxy grout maintains its color consistency over time, unlike cement-based grouts, which may darken or change color with age.
5. Higher flexibility: Epoxy grouts are more flexible than cement-based grout, allowing for slight movement and expansion and contraction of the tiled surface without cracking.
6. Can be used for a wide range of applications: Epoxy grout can be used indoors and outdoors, in residential and commercial settings, and in various types of tile installations.

Cons of Epoxy grouts

1. The complexity of Installation: Epoxy grout requires careful mixing and application, and its fast curing time means that installers need to work quickly and efficiently.
2. Limited Working Time: The short working time of epoxy grout means that installers must work in small sections and clean up excess grout promptly to avoid difficult-to-remove residues.
3. Difficult to Remove: Once epoxy grout has cured, it can be challenging to remove, requiring specialized tools and techniques.
4. Potentially Hazardous: Epoxy grout contains chemicals that may emit strong odors during mixing and application, requiring adequate ventilation and protective equipment.
5. Higher cost of installation: Epoxy grout tends to be more expensive than traditional cement-based grout, which can increase the overall cost of a tiling project.

How to Damage an Epoxy Grout?

An epoxy grout can be damaged due to the below 5 reasons.

1. Heavy impact on the epoxy grout: The epoxy grout can be damaged due to dropping heavy objects or tools onto the tiled surface, which can chip or crack the epoxy grout
2. Using abrasive cleaners or tools: Epoxy grout can be damaged when using abrasive cleaners or tools for cleaning purposes.
3. Chemical exposures to the epoxy grout: The epoxy grout can be damaged due to strong chemical or acidic substances such as bleach, ammonia, or vinegar over time.
4. Open to excessive water: Epoxy grout can be damaged due to prolonged exposure to standing water or excessive moisture. This can weaken the grout by decorating over time.
5. Sudden temperature changes: Extrem temperature fluctuation can cause expansion and contraction of the tiled surface, leading to stress on the epoxy grout and potential cracking or separation from the tile.

What are the Most Used Epoxy Grout Brands?

The most used epoxy grout brands are Laticrete, Mapei, Custom Building Products, TEC, Ardex, Schluter Systema and Bostik

Where Should You Not Use Epoxy Grout?

You should not use epoxy grout when the substrate is not stable, exterior and exposed to extreme weather conditions, expansion joints, and natural stones. Because these can loosen the bond with the substrate or crack the epoxy grout over time.

1. Do not use on unstable substrates: You should not use epoxy grout on unstable substrates that are prone to movement or setting, such as wooden floors or flexible surfaces. You should use epoxy grouts on surfaces that are less inclined at 1/360 degrees.
2. Do not use for exterior applications: You should not use epoxy grouts in outdoor applications that are exposed to extreme weather conditions, such as direct sunlight, freezing temperatures, or heavy rainfall.
3. Do not use epoxy grouts on expansion joints: You should not use epoxy grouts on expansion joints which tend to expand and contract over time. You can use flexible grout in such places.
4. Do not use epoxy coating on natural stones: You should not use epoxy grouts on natural stones because compounds in the grout can interact with the stone particles and that affects the performance.