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How To Level A Floor For Tile

Your tile is only as good as what's underneath. Make sure that the surface under your floor, the subfloor, is smooth and level before you start laying tile.

Quick Tip

Spray the subfloor with water before you install subfloor prep products. If the water doesn't absorb immediately, you need to clean your substrate to remove contaminants.

Picture of a slate of concrete with a crack in it.

1. Be safe
A kitchen covered in remodel sheets, painters tape around the cabinets, and cement board on the floor.

 Before you begin, make sure you have a clear, safe installation area. Remove anything that could be in your way, and cover all surfaces that you are not tiling to protect them from installation debris.









2. Know your substrate
A picture showing dirt, a concrete board, & flooring getting warped with a arrow emphasizing moisture.Most floor tile can be installed over a variety of substrates – as long as they are structurally sound and solid. If you are tiling over concrete, new slabs must be cured at least 28 days. If you are tiling over plywood, plywood should be APA Grade Trademarked Exposure I (Underlayment grade or better). You must have 2 layers of plywood with a minimum total thickness of 1-1/8" over floor joists that are spaced 16" apart. These two layers must be fastened with adhesive and screws or nails per manufacturer’s instructions. A structurally sound subfloor helps prevent moisture from getting into the slab, which warps and buckles flooring.





3. Glue down loose areas
A picture of cement boards on the floor.Any loose areas of your substrate should be glued, nailed or screwed down tightly. After all your hard work, you don’t want a floor that’s bouncy or squeaky! If you are tiling over old tile or vinyl linoleum, any loose tiles must be secured. Linoleum must be noncushioned and fully adhered to the substrate. Any section of wallboard or other surface that has been damaged by moisture must be replaced. If installing new backerboard, be sure to follow manufacturer’s instructions. Check with your tile manufacturer to make sure your substrate is acceptable.





4. Fill holes and voids in floor

A hole in cement with mud and a hand holding a trowel.The substrate must also be flat and even, without holes or voids. Use a 6’ or 8’ long straight edge (2” x 4”) to make sure that there are no gaps greater than ¼” when the straight edge is placed across the tiling surface. If a concrete or approved wood substrate is not quite level, don’t worry. Replacement is not necessary. Fill any holes, cracks, voids and depressions with TEC® Skill Set Fast Setting Patch. Keep your installation timeline on track with this fast-setting product – it sets within 40 to 45 minutes. If the variation spans a larger portion of your substrate, consider using TEC® Skill Set™ Self Leveling Underlayment. This easy-to-use product is walkable in 2-4 hours, and allows for floor covering installation in 12-16 hours.




5. Clean the area
A person in work boots sweeping with a yellow broom.Your substrate must be clean, dry and free of contaminants, including grease, sealers, dirt, dust and debris. Linoleum should be stripped and cleaned. You want your tile to stick, and those contaminants can interfere with the adhesion process. Allow the surfaces to thoroughly dry before beginning to tile.



After learning how to level a tile floor make sure you sweep the area clean before setting any tile. Discover how to lay tile in the next page of this guide from TEC Skill Set.

Our diy Expert

Ron Sheldon

Ron Sheldon is a tile and floor installation guru. He has far too much knowledge on obscure topics like grout and floor leveling. A passionate tile contractor by trade, Ron’s spent the past decade dedicated to educating people about tiling, and has great advice on how to perfect your project.

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