How to Perfectly Lay Tile on Concrete

Before you begin tiling, you’ll need to clean and prepare the concrete subfloor. To do this, sweep or vacuum the surface to remove any dust and debris then clean it with TSP (trisodium phosphate) according to the manufacturer’s directions. TSP comes in liquid or powder form. Cleaning with TSP will help remove dirt, grime, and grease from the surface.

Repair cracks in the concrete subfloor with concrete filler or mortar depending on the size of the crack and allow it to dry. Finally, prime the subfloor with concrete primer. This will also seal the concrete.

Use your level to determine if the subfloor has any low or high spots. If it does, those spots will need to be leveled before laying the tile on the concrete. 

Check the primer you used to see if you should use a specific brand or type of self-leveling concrete. When the paint is dry, mix the self-leveling concrete or get out your pre-mixed product and begin applying it to the surface. 

Self-leveling underlayment will spread itself out, with a little help from a broom or trowel, and fill in any low spots, holes, or pock marks, creating a level surface on which to lay tile onto concrete. Allow the concrete to cure completely before moving onto the next step.

Concrete expands and contracts with fluctuations in temperatures, and tile laid over concrete will often crack as a result. Installing an anti-fracture membrane can add a layer of protection between the materials and reduce the likelihood that the tile will crack. 

To install an anti-fracture membrane, you’ll have to choose between the liquid or sheet form. Wait until any crack filler or self-leveling concrete has dried completely and then if you’re using anti-fracture membrane sheets, apply thinset and lay the sheet on top, smoothing with a trowel as you go. If you’re applying liquid anti-fracture membrane, use a roller brush to paint a thick coat over the subfloor. In either scenario, wait for the anti-fracture membrane to dry completely before moving onto the next step.

With the prep work done, it’s time to move onto the fun part—seeing how your tiles will actually look on your floor. To do this, you’ll do a dry lay. All this means is that you’ll lay out all of the tiles on the floor without any adhesive to make sure you like how they look and that they fit in the space. This will also help you see where you’ll need to make cuts and how many tiles you’ll be cutting. 

Start by identifying the center of each wall and snapping a chalk line across the length and the width. Where they meet is the center of the room. 

Unpack all of your tiles and, beginning at the center of the room, lay them out in your desired pattern, covering the entire floor and checking for any tiles that are damaged or don’t match the rest. Adjust the layout as needed to avoid making awkward cuts or having to cut very small pieces of tile.

You can mark any tiles that will need to be cut, but hold off on cutting them until it’s time to actually install them. Once you’ve done your dry lay and marked your edge tiles, you can remove all of the tiles, stacking them neatly, so they are easy to re-lay after the mortar is spread on the surface.

After your dry lay is done and the tiles have been removed, it’s time to mix the mortar and get ready for the actual installation. Mix the mortar according to the manufacturer’s directions, making sure to only mix the amount that you need for the project.

The moment has come—let’s lay some tile! Work in small sections depending on the size of your tiles. For larger tiles, you may work in larger sections, and for smaller tiles, you may work in smaller sections. 

Typically, it’s a good idea to begin in the middle of the room or space and work outward, but in some smaller spaces, it may make more sense to begin in a different spot like the back wall or in a corner. 

Evenly spread the thinset mortar on the subfloor with the notched trowel. When the mortar is evenly spread, begin laying your first row of tiles. Cut tiles as needed. Often, you can cut tiles with common tools depending on the type of tile.

Place spacers in between each tile to create a consistent gap that will later be grouted. Continue to lay tiles, making cuts as needed, until the entire floor is covered with tiles that are evenly spaced. Use your tile saw and tile nippers to cut the tiles to size, and use the dremel tool to cut any holes needed. Check each tile to make sure it's level with those surrounding it.

The mortar will need between 24 and 48 hours to fully dry and set. Keep people and pets off of the floor during this time to avoid causing any damage or shifting to the tiles.

Once the mortar is dry and the tiles are fully adhered to the subfloor, mix your grout according to the manufacturer’s directions. In some cases, you can purchase pre-mixed grout which will save you a step.

To grout tiles, you’ll need your grout, rubber grout float, a tiling sponge, and a bucket of water. Spread the grout over the tiles and into the gaps between the tiles until the gaps are filled. Scrape off as much excess grout as possible and then remove the rest with the tiling sponge. Repeat until the whole floor has been grouted. Let the grout dry for 48 hours before moving onto the next step. 

If grout haze—a cloudy film that covers the tile—appears, you should wipe it off using a damp cloth. Removing grout haze as soon as possible after it appears will make it easier than if you wait and do it days or weeks later.

After the grout is thoroughly dry, apply your grout sealer using a small brush to brush it onto each grout line keeping as much off of the tile surface as possible. You can also use a spray sealant that can be sprayed on the entire surface and will wear off of the tile as the floor is used. Doing this will help reduce the amount of floor tile grout cleaning you’ll have to do later. Once the sealant is dry, your new tile floor is ready to go!