QA

Question: How To Prepare Subfloor For Tile

Can you lay tile directly on subfloor?

Tile can be laid on plywood. But do not install tile directly on the plywood subfloor itself. Use an intervening layer of a sheet of thinner plywood.

How smooth does subfloor need to be for tile?

A subfloor is the bottom-most structural level of your floor. A good subfloor needs to be durable, level, at least 1 ⅛ inches thick, and free from residue. If it is not, it won’t support tile well. Even the smallest cracks or depressions in a concrete floor could cause your tile to break early.

What subfloor should be under tile?

Exterior plywood is an acceptable underlayment for tile and is preferred to interior-grade plywoods because the bonding adhesives used are waterproof. If water seeps through the tile installation to the underlayment, it will not cause the wood to swell, as happens with interior-grade plywood.

What should I put down before tiling?

Underlayment is something you put on top of your substrate to prepare it for tiling. The substrate (or subfloor) is the ground, whether it’s made of plywood or cement. Cement board or backer board are the most standard underlayments. They come in various thicknesses for different spaces.

How do you prepare a wooden floor for tile?

Tiling over floorboards is possible with the use of plywood or backer boards. In short, a layer of ‘board’ over your floorboards will keep the surface you’re tiling strong and sturdy, and help you minimise any movement from your old floorboards.

Do I need cement board under floor tile?

Whenever you’re laying tile on a wood subfloor, you need to first install cement backer board. You also can’t safely install tile flooring over plywood subfloor or onto an unprotected wood floor. If you did, there’d be a serious risk of rot, water damage, warping and mold. Plus, your tile and grout would likely crack.

Do I need a membrane under tile?

If tile is laid directly on top of concrete, this expansion and contraction will cause stresses that fracture or delaminate the tile. Other less common and more challenging substrates like asphalt and metal require an uncoupling membrane to ensure the tile will adhere to these surfaces.

Do I need to self level before tiling?

Before installing tile on your floor you must make sure your floor is properly prepared. A properly prepared floor does not have to be level. It must, however, be flat. If your floor will not be subjected to water regularly, such as a kitchen or bathroom floor, it does not necessarily have to be level.

How thick should tile subfloor be?

The subfloor under the tile should be at least 1 1/8″ thick, with a minimum of 5/8″ thick exterior grade plywood topped by 1/2″ cement backer board.

Is Ditra better than cement board?

Ditra is waterproof, while cement board lets water through but won’t be damaged by it. This may make Ditra a better choice if moisture from below is a concern, such as with some outdoor applications or installations over concrete.

What is underneath a subfloor?

Underlayment The underlayment material is installed below the floor covering and placed on top of a sub-floor. Under the visible covering, there is a layer made of soft or foam-like materials with a thickness of between 1/4- or 1/2-inch.

How thick should cement board be for tile?

Floors: A 1/4-inch minimum thickness is needed, but thicker panels are also fine. Walls: Use 1/2-inch or 5/8-inch-thick cement board, not 1/4-inch. The extra thickness is needed when spanning the studs and it provides a solid base for the tile.

Can you use 1/4 inch cement board on floors?

1/4″ USG Durock® cement board is an ideal substrate for floor and countertop ceramic tile installations. The 1/4″ thickness helps eliminate transition trim when abutting carpet or wood flooring and minimize level variations with other finish materials.

Do you PVA wood floor before tiling?

Short answer. No, never use PVA to prime a surface before applying tiles. The acetic acid produced when cement and PVA come into contact would render the adhesive and grout useless.

Do I need to prime plywood before tiling?

Do I need to prime plywood before tiling? Some helpful tips: In general, if the subfloor for tiling is made up of plywood, you don’t have to use a primer. Instead, the plywood preparation is done so that it is made water-resistant and more adhesive suitable without using a primer.

Can I just screw down cement board?

Screw and Joints Do not use drywall screws as they are not recommended to be used to hold the backer board in place. All of your backer board pieces should be cut before they are placed on​ the floor. It is important to highlight that screws shall not be installed all the way down to the floor joists.

Can you use plywood instead of cement board?

Better Adhesion The best argument when determining whether to use plywood or cement board under tile is in the adhesive process. Plywood is porous, and not designed for use with most of today’s latex-based thinset mortars. Cement backerboard is designed specifically for this use.

What can I use instead of backer board?

Glass mat gypsum board is a better choice. Sheets of glass mat gypsum are made from water-resistant silicone-treated gypsum, reinforced on both sides by fiberglass mats. DensShield is one common brand. It is easier to cut than cement board, it is mold resistant, and it has a built-in moisture barrier.

What is crack isolation membrane?

On concrete floors, crack isolation membranes, also known as crack I products, are designed to absorb the stresses produced by movement in the concrete. The purpose of the membrane is to stretch with the movement of the concrete, but not allow this movement to telegraph to the face of the tile or grout joint.

What goes on the wall before tile?

Patch any holes or cracks with spackling compound and sand the entire surface with medium-grit sandpaper. Vacuum to remove dust. Remove any remaining dust, oils and grease from the wall with TSP (tri-sodium phosphate) or an ammonia-based cleanser. Let the wall dry completely before beginning tile installation.

How thick should Ceramic tile underlayment be?

The floor and subfloor combined should be at least 1-1/8 inches thick for proper support. If your existing floor is covered in cushioned vinyl or linoleum, it’s best to remove it, but you can also cover it with an underlayment.