Tile grout is the material used to fill the spaces between tiles on floors, walls, countertops, and other surfaces. Grout acts as an adhesive to hold the tiles together while also preventing moisture and debris from getting below the tiles.
Over time, tile grout can become discolored, cracked, or permeable. Re-sealing the grout at regular intervals is an important maintenance task that will protect the integrity of the tiles and prevent staining or damage. There are two main categories of tile grout sealants: cement-based sealers and epoxy-based sealers.
Cement-Based Tile Grout Sealants
Cement-based grout is the most common type used for sealing tile. It consists of a mixture of cement, fine aggregate, and color tints. Cement grout is water-soluble and porous. As such, it needs to be sealed regularly to prevent absorption of moisture and staining.
Cement grout sealers work by coating the grout surface with a water-resistant barrier. They soak into the grout and create bonds within the pores. There are several types of cement grout sealers to consider:
Silicone tile grout sealers provide a flexible, waterproof coating. Silicones have ultra-small molecules that penetrate deeply into cementitious grout. They line the pores with a hydrophobic barrier that repels water while still allowing vapor transmission.
Advantages of silicone sealers:
- Deep penetration for long-lasting protection
- Maintain vapor permeability
- Easy application with roller or brush
- Low odor and non-toxic
- Repeated applications can leave a glossy film on tile surface
- Less effective on highly porous or flawed grout
Acrylics are a popular cement grout sealer for their affordability and ease of application. They contain acrylic resins suspended in a water-based solution. Acrylics penetrate the top layer of the grout and form a protective acrylic polymer barrier.
Advantages of acrylic sealers:
- Low cost and readily available
- Very easy to apply with roller or brush
- Good for sealing hairline cracks
- Enhance color uniformity
- Only provide surface-level protection
- Repeated applications can leave a hazy film
- Less effective for highly porous grout
Epoxy Resin Sealers
Epoxy resin grout sealers offer more complete, long-lasting protection compared to acrylics and silicones. They contain two components – an epoxy resin and a catalyst – that undergo a chemical reaction when mixed to form a durable, plastic-like coating.
Advantages of epoxy resin sealers:
- Provide deep penetration and a complete seal
- Withstand chemical exposure and hot temperatures
- Long-lasting protection, 5-10 years
- Enhance resistance to abrasion and staining
- More difficult to apply than silicone or acrylic
- Limited vapor permeability
- Surface needs proper prep and cleaning beforehand
Urethane is a type of plastic polymer commonly used for coatings and sealants. For grout sealing, single-component moisture-cured urethanes provide an optimal balance of protection and breathability.
Advantages of urethane grout sealers:
- Form flexible, waterproof coating in grout joints
- Maintain vapor permeability
- Withstand freezing, hot water, and UV light
- Long-lasting protection, 3-5 years
- More expensive than acrylics
- Two coats often required
- Surface prep is very important
Epoxy-Based Tile Grout
Epoxy grout differs from cement grout in that it consists of an epoxy resin mixed with a catalyst plus pigments for color. Epoxy grouts provide an extremely durable, stain-proof alternative to cement. However, epoxy grouts also require sealing to maintain performance.
There are epoxy-based sealers specifically designed for use with epoxy grouts. These sealers differ from cement grout sealers in their chemical composition:
Epoxy Film Forming Sealers
Epoxy film formers provide a protective coating of clear epoxy over the colored grout. They contain solvent-borne or water-based epoxy resins that cure to a glossy, plastic-like film when applied.
Advantages of epoxy film forming sealers:
- Provide a thick surface coating for maximum protection
- Highly resistant to chemicals, acids, and high temperatures
- Enhance abrasion resistance
- Can yellow or darken over time
- Poor vapor permeability
- Surface imperfections show under glossy film
Polyurethane is a versatile polymer often used in protective coatings. For epoxy grout sealing, single or dual-component polyurethane sealers offer excellent protection.
Advantages of polyurethane epoxy grout sealers:
- Abrasion, stain, and chemical resistant
- Maintain vapor permeability
- Withstand hot and cold temperatures
- Less prone to yellowing than epoxy
- Typically more expensive than epoxy sealers
- Fumes during application require ventilation
- Multiple coats often required
Penetrating Epoxy Resin Sealers
Unlike film forming sealers, penetrating epoxy resins soak into the top layer of the grout joints without leaving a coating on the surface. These thin resins densify and strengthen the epoxy grout for better protection.
Advantages of penetrating epoxy sealers:
- Deepen color and enhance joint appearance
- Allows vapor transmission
- Resist acids, chemicals, and high heat
- Easy application with roller or brush
- Do not provide a surface coating or film
- Repeat applications needed for ongoing protection
- Not as thick or durable as epoxy film formers
How to Choose the Best Grout Sealer
With the variety of tile grout sealers available, it can be tricky to determine which is the right product for your needs. Here are tips for choosing the optimal sealer:
Consider the grout type – Match the sealer formulation to either cement-based or epoxy-based grout. Using the wrong sealer can result in inadequate sealing.
Determine coverage area – Estimate the total square footage of grout joints to ensure purchasing enough sealer. Most products cover 75-150 sq. ft. per quart.
Assess porcelain vs. ceramic tile – More porous, absorptive tiles like ceramic require a sealer that penetrates deeply into the grout for maximum protection.
Consider sealer lifespan – How long do you want the sealed grout to last before reapplying? Sealers like epoxy and polyurethane provide 5-10 years of protection.
Evaluate ease of application – Opt for a convenient roller or brushable formula unless you plan to apply with a lambswool applicator.
Read manufacturer guidelines – Check requirements for surface prep, application methods, drying time, and any limitations.
Check VOC content – Low VOC sealers are safer for indoor use. Make sure the product is compliant for your state regulations.
Consider appearance – Decide if you want to enhance grout color or prefer maximum transparency.
Applying Tile Grout Sealers
To achieve the best results with grout sealing, proper application technique is crucial:
Read all label instructions – Follow manufacturer’s guidelines for correct application methods, dry times, and any precautions.
Clean and dry grout joints – Remove any dirt, grime, grease, or waxes from grout to allow maximum sealer penetration.
Tape off surfaces – Use painters tape to protect tile edges and avoid accidentally sealing the tile surface.
Ventilate the space – When using solvent-based sealers, ensure adequate airflow to dissipate fumes.
Apply thin, even coats – Apply sealer horizontally with a small foam roller or brush using thin coats. Avoid puddling.
Maintain wet edge – Keep a wet edge as you apply by overlapping sections. Work in small sections of 5-10 sq. ft.
Allow proper curing – Most sealers require 24-72 hours curing time before exposure to water or traffic.
Apply second coat if needed – For epoxy or urethane sealers, a second coat often maximizes performance.
Remove tape and residue – Carefully remove all painters tape after application. Wipe any sealed areas of tile if needed.
Check coverage – Look for missed or insufficiently sealed areas and spot treat as needed for complete protection.
Troubleshooting Grout Sealing Issues
Despite best efforts, grout sealing doesn’t always go as planned. Here are some common problems and solutions:
Whitish haze on tiles – Insufficient removal of excess sealer. Use a TILE CLEANER/BUFFING PAD to remove residue.
Flaking or peeling – Sealer applied too thickly or surface not properly prepped. REAPPLY using thin even coats.
Discoloration – Certain sealers can yellow over time, especially in sunlight. RESEAL with a more color-stable product.
Staining persists – Sealer unable to penetrate flawed or highly porous grout. CONSIDER EPOXY GROUT RESURFACING.
Wearing away quickly – Inferior sealer used or applied incorrectly. RESEAL with a HIGH-QUALITY SEALER using proper methods.
Grout still absorbing water – Not enough sealer applied to fill grout pores. APPLY AN ADDITIONAL COAT of sealer.
Flaking when wet – Typically caused by moisture underneath. IDENTIFY AND REPAIR any underlying leaks or sources of moisture.
Haziness develops over time – Indicates the sealer is wearing away. PLAN to reseal grout at regular intervals.
Discoloration at joints – Dirt or contaminants in grout Preventing penetration. CLEAN with GROUT CLEANER before resealing.
Peeling up from joints – Improper rinsing after grout installation. REGROUT affected areas and ensure proper drying before sealing.
Maintaining the Sealed Grout
Grout sealer application should be thought of as an ongoing maintenance process. Sealed grout requires proper care to make sure it looks its best and avoids damage:
- Limit use of harsh cleaners which can degrade sealers – use gentle PH-neutral cleaners instead
- Spot clean spills quickly to avoid staining of sealed grout
- Sweep or dry mop floors frequently to prevent abrasive dirt buildup
- Re-apply sealer at regular intervals per manufacturer instructions
- Watch for signs of wear such as fading, absorption of moisture, or staining
- Avoid excessive moisture on sealed grout from leaks, pets, plants, etc.
- Consider re-coloring grout if discoloration occurs over time
- Clean with grout brush or steamer annually to remove deeper dirt
- Use caution with acids like vinegar or citrus which can break down sealers
- Avoid using waxes, soaps, or film-forming cleaners on sealed grout
- Use trivets, mats, and cutting boards to protect counter grout
Regular grout sealing provides immense benefits for protecting the finish of tiled surfaces. Selecting the right formulation of sealer based on your specific tile and grout type is key to maximum performance. With proper application and ongoing maintenance, sealers can maintain the integrity and appearance of grout lines for years before reapplication is needed. Paying attention to details like cleaning, drying, ventilation, and coverage when applying sealers prevents many common problems. A quality grout sealing job keeps grout looking new, while preventing costly damage or repairs down the road.
Frequently Asked Questions
What is the main difference between cement-based and epoxy-based grout sealers?
The main difference is that cement-based sealers are designed to penetrate and seal cement grouts, while epoxy-based sealers are formulated to seal epoxy grouts. Cement sealers enhance porous cement grout while epoxy sealers add a protective coating to already-dense epoxy grout.
How often should tile grout be sealed?
Most quality grout sealers last 3-5 years before needing reapplication. However, the sealing frequency depends on the sealer type, traffic, exposure to moisture, and cleaning methods. High traffic floor grout may need sealing yearly, while wall or counter grout may go 2-5 years betweenapplications.
Should all types of tile and grout be sealed?
Sealing is most critical for cement grout and porous, absorptive tiles like ceramic or natural stone. Epoxy grout and less porous tiles like porcelain may not require sealing. The grout manufacturer’s recommendations should always be followed.
What’s the best way to apply grout sealer?
Using a small foam roller, apply a thin, even coat horizontally across grout lines. Maintain a wet edge and work in small sections. Allow the proper drying time before applying a second coat or exposing to moisture. Removing excess sealer quickly from tiles prevents haze.
How do you know when it’s time to re-seal grout?
Signs that re-sealing is needed include: absorption of water into grout, darker or inconsistent color, staining, visible wear, flaking or peeling, growth of mold or mildew, and generally deteriorating joints. Re-seal at the interval recommended by the sealer manufacturer.
Can you change the color when re-sealing grout?
Yes, when re-sealing, a compatible grout colorant can be applied separately or added to clear grout sealer. This allows refreshing the color while still protecting with a fresh application of sealer.