Resealing grout is a simple but important weekend project that protects your porous cement-based grout from moisture, mold, and stains. The process takes just a few key steps:
Yes, you can absolutely seal grout yourself. It is a highly manageable DIY project that requires very few tools and will extend the life of your tile.
Yes. I used the StoneTech (now DuPont) bulletproof sealer. Worked amazingly well and lasted a long time. Apply with a roller or brush bottle for grout lines.
Yes, you should reseal your grout. While sealing is not strictly mandatory, standard cement-based grout is highly porous and acts like a sponge, absorbing water, oils, soap, and dirt. Resealing provides a vital protective barrier, making the grout stain-resistant and preventing mold, mildew, and water damage.
Without a proper seal, all kinds of nasties—think mold, mildew, and grime—can seep in and set up camp. Sealing your grout creates a barrier that keeps the yuck out, making it easier to clean and maintain.
Builders often skip sealing grout to cut costs, save time, and avoid returning to the job site. Additionally, many modern polymer-modified grouts are stain-resistant, and sealing un-cured grout can trap moisture. Some installers even use it as an upsell or exclude it because sealing can leave a hazy film on certain tiles.
Grout sealer typically lasts between 1 to 5 years, but the exact lifespan depends on the type of sealer used and the location of your tile.
The best overall grout sealer is Miracle Sealants 511 Impregnator. It is a highly penetrative, solvent-based sealer that absorbs deep into porous cementitious grout lines to form an invisible, oil-and-water-resistant barrier without changing the natural look of your tile or grout.
Unsealed grout absorbs water continuously, which can lead to staining, mold growth, and eventually water infiltration behind the tile. Over time, this moisture can damage the wall substrate, create structural issues, and require expensive remediation work that goes well beyond simple tile repair.
Technically, you can regrout over old grout, but it is not recommended to just smear new grout on top. Doing so will likely result in a weak bond, leading to cracking, peeling, and an uneven finish.
Yes, Dawn dish soap is excellent for cleaning grout because its gentle, grease-cutting formula will not strip sealers or discolor tile. For everyday maintenance, simply mix a dime-sized squirt of Blue Dawn in a 32-oz spray bottle of warm water. For tougher grime, you can upgrade to a deeper-cleaning DIY mixture.
When choosing between spray and brush grout sealers, spray is faster and better for large floor spaces, but wastes product and requires cleaning the tile surface. Brush (or roller) application takes longer but offers precision control, ensuring the sealer only goes on the grout without splattering.
Straight vinegar or another stronger acid will dissolve the top layer of the grout, so even if dirt and stains are removed, part of the grout is too, which means you'll need to regrout sooner. Vinegar and similar acids are also bad for stone tile because acid can cause etching in the stone.
Unlike a thin, clear sealant that wears away quickly, grout color sealing utilizes a durable epoxy-based formula. This advanced sealant penetrates the porous grout and creates a non-porous, permanent bond.
To make old grout look new again, start by deep cleaning with a mixture of baking soda and 3% hydrogen peroxide. For stubborn, permanent stains, apply a colorant like a Grout Paint Pen or Grout Refresh Sealer, which permanently dyes the lines to your choice of a fresh color.
One of the most frequent grouting mistakes is improper mixing and application. Grout is a precise material, and getting this step right is crucial for its strength and adhesion. Incorrect Water-to-Grout Ratio: Adding too much or too little water can significantly weaken the grout.
Builders often skip sealing grout to cut costs, save time, and avoid returning to the job site. Additionally, many modern polymer-modified grouts are stain-resistant, and sealing un-cured grout can trap moisture. Some installers even use it as an upsell or exclude it because sealing can leave a hazy film on certain tiles.
Professional grout sealing costs between $𝟏.𝟓𝟎 and $𝟒.𝟎𝟎 per square foot for labor and materials, or roughly $𝟏𝟐𝟓 to $𝟑𝟎𝟎 for a standard bathroom or kitchen area. If you DIY, you can seal the grout yourself for as little as $𝟎.𝟐𝟎 to $𝟎.𝟓𝟎 per square foot in supplies.
Perform a simple "water drop test" to determine if your grout is sealed. Splash or spray a few drops of water onto the dry grout and wait 5 to 10 minutes. If the water beads up or sits on the surface without changing color, it is sealed. If the water soaks in and darkens the grout, the seal has worn off and needs to be reapplied.
Sealing grout creates a protective, stain-resistant barrier, but it comes with several disadvantages. It requires frequent reapplication, traps moisture if applied incorrectly, is not foolproof against staining, and adds upfront costs.
Some may use mechanical brushes to scrub grout and remove tough stains. From there, professional cleaners may use a wet vacuum to extract dirty water and cleaning residue to dry the area, completing the job with a grout sealer to protect against future stains.
Grout sealer creates a protective, water-resistant barrier that helps keep moisture out and prevents stains from soaking into the porous grout lines. It does not make grout 100% waterproof, but it is a vital maintenance step for preventing mold, mildew, and water damage in showers, bathrooms, and kitchen backsplashes.
To prevent the development of mold and mildew, it is important for you to seal your grout at least once a year. However, one of the best practices for you is to seal grout every six months in high traffic areas. Moreover, you can seal grout every two years in low traffic areas.
Clean old grout thoroughly if you are resealing old tile. Soapy water and a small, stiff-bristled brush work best. Allow the grout an hour to fully dry before sealing. Use tape and/or plastic or masking paper to protect baseboards, fixtures, and surrounding areas.
Regrouting is the best option when tiles and grout begin to show signs of discoloration or the stains are so deep that they cannot be removed. As grout ages, it naturally deviates from its original color. If the white grout turns yellow or is covered with stains, you must regrout very soon.