Laying tile on a plywood subfloor can seem daunting, but with proper preparation and the right techniques, it can be a DIY project that creates a beautiful and durable finished floor. Here is a comprehensive guide on how to lay tile on plywood to help you through the process.


Tiling over plywood subfloors is a common practice to create a surface ready for ceramic, porcelain or natural stone tile installation. Plywood provides a stable, smooth and rigid base that allows the tiles to be firmly bonded using the right adhesives and techniques. With proper planning and preparation, you can create a gorgeous tiled floor over a plywood subfloor foundation.

Benefits of Using Plywood Subfloors for Tiling

There are several benefits to using plywood as a subfloor for tiling:

  • Stability: Plywood creates a stable surface that limits movement and flexing which could otherwise crack grout and tiles.
  • Smoothness: The smooth and even surface of plywood allows for a consistent adhesive bond and prevents lippage issues between tiles.
  • Moisture resistance: Plywood provides a moisture barrier protecting the structure below from water damage.
  • Level surface: Any minor dips or bumps in the subfloor can be sanded down to create a flat tiling surface.
  • Affordability: Plywood is an affordable and accessible subflooring option.

With proper preparation, plywood makes an excellent subfloor for directly bonding ceramic, porcelain or natural stone tile.

Choosing the Right Plywood

Not all plywood is well-suited for tile subfloors. Here are some tips on selecting the right plywood:

  • Use minimum 5/8-inch exterior-grade plywood. This thickness provides stability and prevents flexing. Marine-grade offers moisture resistance.
  • Avoid softwood plywoods like pine which are more prone to swelling and deterioration over time.
  • Look for plywood with a smooth sanded face without knots or gaps to allow for a flush tile installation.
  • Use tongue and groove plywood panels for a tight seamless subfloor installation.
  • Choose plywood with an A grade that has few surface defects for even tiling.

Getting high-quality, exterior grade tongue and groove plywood ensures optimal stability and prevents unevenness under the tile.

Preparing the Plywood Subfloor

Proper preparation is crucial before laying tiles. Follow these key steps:

Check for Moisture

Excess moisture under the floor can cause tiles to crack or loosen over time. Test moisture levels using a moisture meter. Levels should be:

  • Wood subfloors: Less than 12% moisture content
  • Concrete subfloors: Less than 3 lbs per 1,000 sq ft per 24 hours

If moisture is too high, use a sealer or moisture barrier primer before tiling.

Ensure a Smooth Surface

Sand down any bumps, uneven joints, or surface defects. The surface should be flat within 1/8 inch over 10 feet. Fill any holes or gaps with a patching compound.

Clean Thoroughly

Sweep then mop the surface to remove dust, oils and debris which prevent adhesion. Ensure the plywood is clean before tiling.

Seal and Prime

Apply waterproof ceramic tile primer to seal the surface and improve adhesion. Avoid acrylic-based primers for plywood.

Proper prep removes potential bonding issues and creates the ideal subfloor for tiling.

How to Lay the Tile

Once prepped, you can begin laying the tiles:

Choose Your Adhesive

Use a polymer-modified thinset mortar which bonds well to both wood and tile. Avoid organic adhesives which deteriorate over time.

Prepare the Tiles

Soak porous tiles in water if necessary to prevent uneven drying and shrinking after installation. Mix grout in a bucket.

Spread the Thinset

Use a notched trowel to spread a thin, even layer of thinset mortar over a small section of the floor at one time.

Set and Space Tiles

Place tiles firmly into the wet thinset, spacing evenly. Use tile spacers for consistent grout lines. Periodically lift a tile to check adhesive transfer.

Finish Grouting

Let the thinset cure fully per manufacturer instructions. Mix grout per instructions and apply over the tiles, cleaning excess as you go and sealing once fully cured.

Following these simple tiling steps allows you to transform a plywood subfloor into a stunning tiled floor.

Tips for Successful Tiling on Plywood

Follow these top tips:

  • Stagger tiles in a brick pattern for strength.
  • Mix tiles from several boxes together for consistent coloring.
  • Use a leveler system to keep tiles even and flat during installation.
  • Cut plywood seams for screwheads to avoid creating bumps in the floor.
  • Limit joist spacing to 12 inches on center for stability.
  • Use uncoupling membranes for helping prevent cracks.
  • Add movement joints for large tile sizes or areas prone to shifting.

Proper planning and prep work helps ensure your tiled plywood floor stands the test of time.

Frequently Asked Questions

What thickness of plywood should be used under tile?

Use at least 5/8-inch exterior-grade plywood for a tile subfloor. Thicker 3/4-inch plywood adds stability for natural stone tiles in high traffic areas.

Should I use greenboard or cement board over plywood?

Cement board is not necessary over plywood for indoor floor tiles. Greenboard offers moisture resistance if adhesive failure is a concern.

How do you prepare plywood for tile installation?

Sand any bumps, fill gaps and holes, seal surface, prime plywood, then apply thinset mortar per manufacturer instructions before laying tiles.

Can you tile directly over OSB subfloor?

OSB is prone to swelling and deteriorating with moisture exposure. Use a cleavage membrane before tiling over OSB or opt for a plywood subfloor.

What thinset is best for plywood subfloor?

Choose a polymer-modified thinset mortar which bonds well to both porous and non-porous surfaces like plywood and ceramic or porcelain tile.


Installing tile over a plywood subfloor can allow you to achieve a beautiful, high-quality tiled floor as a DIY home improvement project. With proper preparation, using the right materials, and correct installation techniques, your tile floor over plywood can look amazing and last for decades to come. Be sure to assess moisture levels, sand the surface, prime the wood, use a suitable thinset adhesive, and properly space and grout the tiles. Paying close attention to subfloor prep work and utilizing the right products will result in a gorgeous, long-lasting tiled floor over your plywood subfloor.