How To Tile A Basement Bathroom Floor?

Tiling a basement bathroom floor can help protect the space's flooring against potential damage from excess moisture. Additionally, tiles can enhance the aesthetics of the space. So how can you tile a basement bathroom floor? We consulted with the experts to give you a concrete answer to that question.

Preparing the underlayment is the first step to installing tiles on a basement bathroom floor. Cleaning, drying, repairing cracks, and leveling the surface are vital parts of the preparation process. After the preparations are complete, the steps to tile a basement bathroom floor are as follows:

  1. Measure the floor.
  2. Draft the tile outline.
  3. Cut the tiles.
  4. Apply thinset mortar.
  5. Apply grout.

The entire tile installation project might look reasonably easy. But failure to do the steps properly can lead to expensive mistakes. Keep reading to learn the details on how to tile a basement bathroom floor to avoid these costly mishaps.

A sleek design in well planned bathroom, How To Tile A Basement Bathroom Floor?

How Do You Prepare A Basement For Floor Tile?

Preparing a basement to install floor tiles, particularly for a bathroom in the nearby area, can help prevent costly problems. A properly prepared basement floor needs to achieve four principles: tidy, dry, repair, and smooth.

Ceremic tile installation


Preparations to install basement floor tiles needs a clean underlayment. Sweep the bare floor to remove dirt, dust, and debris.

After sweeping, wipe the floor with a wet mop. Filth can inhibit the tile from adhering to the underlying layer, causing problems like uneven sealing and irregular leveling. Plus, a clean underlayment can reduce the risks of cracks forming on the tiles.


Let the surface dry, then apply a diluted degreaser on it. Wait until the degreaser dries before proceeding. Then, remove any residual dampness by air drying the surface. You can place a fan near your bathroom basement and direct the air to the floor to speed up this step.


Fix any cracks and dents on the underlayment before the bathroom tile installation. These imperfections can lead to weak spots after the installation. A person stepping on these locations can be at a higher risk of cracking and destroying the tiles.

Use a patch that’s compatible with the underlayment. For instance, use a concrete patch for a concrete surface. However, you may need to consult the help of a professional if the cracks and dents may require more than a relatively simple patch job.

Check out the Red Devil 0644 pre-mixed concrete patch on Amazon.


After fixing the imperfections in the underlayment, you need to ensure that the surface is level. Smoothen any bumps or raised areas with a leveling compound. This solution can make this step fairly quickly.

Take note that an uneven underlayment can promote expensive problems for any tile installation project. If the layer underneath a tiled surface is uneven, it can increase the risks of breakage.

Take a look at the Race Glaze leveling compound on Amazon.

Tiling a Basement Bathroom Floor

Grouting ceramic tiles

Once you finish preparing the underlayment, you can proceed with the tile installation for your basement bathroom floor. But make sure you have the necessary tools and equipment for this project.

What You’ll Need

  • Measuring tape
  • Notched trowel
  • Sponge
  • Tile saw
  • Grout
  • Tile spacers
  • Thinset mortar
  • Tiles

Step By Step Guide

Make sure to follow the correct steps to reduce the risks of costly mistakes. In this section, we’ll tackle each phase of the project in detail.

1. Measure the Floor

Use a tape measure to identify the amount of grout, mortar, and tile needed for the basement bathroom floor. Make sure to write down the measured amounts to purchase the correct quantity for each product.

2. Draft the Tile Outline

After gathering the measurements, draw the tile layout or outline. This drawing will serve as a guide when cutting tiles and laying them over the underlayment.

If you’re going to use a contrasting trim, the edge tile should go first. Lay the next tiles according to your blueprint, particularly those that best fit the available space. Use your tile spacers to ensure that the tiles have even spacing.

3. Cut the Tiles

This step can be easy if you rent or own a tile saw. Otherwise, you can use snap- or pull-tile cutters for this part of the project. Don’t attempt to cut the tile using a traditional handsaw as that tool isn’t built to slice this particular type of flooring efficiently.

Check the Skil 3540-02 tile saw on Amazon.

4. Apply Thinset Mortar

Thinset mortar, also called thinset cement or dryset mortar, is an adhesive solution made by mixing cement, sand, and a water-retaining ingredient. Put a thin layer of your preferred thinset mortar on the basement bathroom floor. Ensure that you’re applying in small sections with the help of a notched trowel.

Place a few tiles after applying a small amount of thinset mortar in a section of the bathroom floor. Don't fill the entire floor with mortar before installing the tiles. Otherwise, you may have extreme difficulty installing tiles in corners because you can't step or walk on the adhesive.

Once all the tiles are in place, let the mortar dry. The humidity and moisture in the area can affect the waiting time for the adhesive to dry. However, it should dry and cure within the first 24 hours in many cases.

The temperature may also affect the thinset mortar's drying time. A basement with a fairly comfortable temperature might make the drying time reasonably quick. For more information on the topic, you can also check out our post: What Is The Ideal Temperature For A Basement?

Check out the SimpleSet pre-mixed thinset mortar on Amazon.

5. Apply Grout

Grout is another type of adhesive used in basement bathroom tile installations. This substance helps prevent cracking and chipping that might occur at the edge of the tiles.

Apply the grout after the mortar is dry. Make sure to apply this substance liberally between the tiles’ spaces. Then, wipe the excess with a damp sponge. It should leave behind a residue called grout haze. But you can clean the leftover after the grout dries, which should take another 24 hours.

After the grout dries, you can also drylock the basement floor to help prevent water and moisture seepage. If you want to know more about how to do that project, check out our post: Can You Drylock A Basement Floor?

Take a look at the Savogran 12860 tile grout on Amazon.

Can You Tile Directly On A Concrete Floor?

It’s not a requirement to prepare an underlayment before installing tiles. Directly setting tiles on concrete can promote problems. If the concrete cracks or shifts, the movements delivered to the concrete will transfer to the tiles. In turn, the tiles will be more prone to cracking and breaking than average.

Should I Seal Concrete Before Tiling?

You need to seal concrete before tiling, regardless of the floor’s age. A new concrete floor or underlayment needs to be clean and dry for a tile to adhere properly. Otherwise, dust, dirt, and dampness can encourage delamination, which will make the tiles peel off the floor over time.

Take a look at the AQUA-X concrete and stone sealer on Amazon.

Is Ceramic Tile Good For Basement Floors?

White bathroom with washing machine

ISO-certified ceramic tiles are good for basement floors, especially that they’re resistant to moisture. This trait is excellent in basements since these spaces are known to be quite damp because of the humidity and water vapor migration from nearby slabs and walls.

However, ceramic tiles can be cold underfoot, and many basements tend to be colder because of their underground locations. Homeowners can counteract this concern by using radiant floor heating systems.

Check out the LuxHeat electric radiant floor under tile heating system on Amazon.

Final Words

Make sure to prepare the underlayment before installing tiles on your basement bathroom floor. Also, you should have the proper measurements for the space to buy and use the correct amount of grout, mortar, and tile.

Stay patient, and let the adhesives dry before moving to the next steps. If done correctly, you should be proud and satisfied with your new tiled basement bathroom floor.

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