How to seal grout: Protect and preserve your tiles

You’ve just finished grouting your beautiful new tile floor. But the question arises, ‘Do I need to seal grout?‘? Short answer: Yes! Often, this important step is neglected, but there are many good reasons for doing so.

With few exceptions, grout – whether sanded or unsanded – is porous. That means it can absorb water. Tile is often installed in bathrooms and kitchens where it (and the grout between the tiles) comes into contact with water, but even in dry areas, wet mopping exposes the grout to water.

The problem arises when moisture seeps into the grout. Over time, this can cause the grout to look dirty, begin to foster mould, or even develop an odour. Grout that is frequently wet can also eventually deteriorate and begin to flake away.

That’s why most professionals and manufacturers recommend putting a sealer on the grout after it has fully dried and cured. This is an easy and inexpensive task any experienced DIYer can do.

So, what type of product is best for sealing grout? Here are some factors and tips to keep in mind:

• You want to use a product specifically classed as ‘grout sealer’. This is not the same as a bathroom sealant, but it is generally found where tile supplies are sold.
• You will likely have the choice of a spray-on sealer or a liquid that will need to be brushed on. Spray sealer is quicker to apply but less precise, so there will likely be more prep work and clean up.
• There are two main categories of tile sealer: penetrating and membrane forming. Penetrating sealer soaks down into the grout for greater moisture protection, so it is preferred in wet areas such as bathrooms. Membrane-forming sealer forms a surface barrier and is better suited to areas that are generally dry.
• Always follow the manufacturer’s instructions on the label. Ensure the sealer is compatible with the type of tile and grout you intend to use it on. If the tile is on a counter or other food-prep area, use a sealer that is ‘food safe’. Also note application details and drying times.

Find a loose or broken tile while applying sealer? Here’s a quick way to reattach it. Try Loctite Extreme Gel, the super versatile problem-solving adhesive. Extreme Gel bonds to nearly any surface, including ceramic, wood, stone, glass, and more. This thick gel dries clear and can fill gaps. It is water and temperature resistant and can even be used outdoors.

Let’s now walk through the process of how to seal grout on tile for a professional finish.

As mentioned above, you will either be spraying the sealer from a pump sprayer or applying it with a brush or small roller. Either way, first some preparations are in order.

Before starting, be sure to wear protective gloves and ensure the room is well ventilated.

1. Make sure the grout is fully cured before beginning. This typically takes 48–72 hours.
2. 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.
3. Use tape and/or plastic or masking paper to protect baseboards, fixtures, and surrounding areas. (You may need to cover a bit more of the surroundings if you are applying the sealer by spraying.)
4. Apply the sealer. Using a brush or roller, cover all the grout joints. Aim for an even coat, ensuring there are no dry spots. (Alternatively, spray the sealer along each line of grout.)
5. Clean any sealant spillover on the tiles within 5 minutes with a clean, dry cloth. 
6. Allow the first coat of sealer to dry for about an hour or as recommended on the label. 
7. Using the same method, apply a second coat of sealer, then wipe down the tile.
8. Allow the sealer to fully dry before using the area. This typically takes about 24–48 hours.

Once you have finished and the sealant is dry, it is always a good idea to check a few spots of the newly-sealed grout with the water drop test. Pooling water is a sign you have a good seal. If the drops are absorbed, you may need another coat of sealer.

Would you like a finishing touch to make wet areas look great and add another layer of moisture protection? Use a waterproof sealant in the corners around sinks, bathtubs, and other areas that receive frequent exposure to water.