Is it better to tile over plywood or cement board?

Author: Mrs. Elda Runte  |  Last update: Sunday, May 4, 2025

One of the first questions that many people before installation is whether to use plywood or cement board under tile. While you can technically install most tiles on any smooth, clean substrate, using cement backerboard will give you superior results every time.

Is it better to put cement board or plywood under tile?

Using cement board for tile floors is generally recommended, especially for areas exposed to moisture, like bathrooms and kitchens. Here's why: Stability: Cement board provides a stable and strong substrate that helps prevent cracking in the tile due to movement in the subfloor.

What happens if you put tile directly on plywood?

The floor will deflect according to the load applied and the stiffness of the structure (joint size, spacing etc). If the adhesive is not flexible or laid thick enough to absorb the amount of movement, the tiles will either delaminate or crack. Large tiles will exacerbate the deflection across each tile's width.

What is the best board to tile over?

The best backer for tile (anywhere) is tile backer (cementboard, DuRock®, HardiBacker® etc.) It's literally made for the job. It costs a bit more than drywall, but in the whole cost of a tile job (materials and labor) it's a very small increment over a less suitable backing such as drywall.

Can I tile directly over cement board?

Can I Tile Directly Onto Cement Board? Yes, cement board is the perfect base for tiling, as it's waterproof and provides a smooth, even surface that won't be disturbed by moisture.

Schluter ditra vs Cement board

Do I need to waterproof my cement board before tiling?

One thing to remember about cement board is that it can be highly absorbent. Without any moisture-resistant properties, it may cause mold and fungal growth if not covered with a waterproof layer before adding tile – especially in areas of high moisture, such as bathrooms.

Do I need to prime cement board before tiling?

Substrates like plaster, drywall, and cement board used in tiling need priming to create an ideal base for tile adhesion. Such substrates are porous and can absorb moisture from the tile adhesive, potentially weakening the bond and leading to tile failure.

Why cement board under tile?

Most projects need 3-foot by 5-foot sheets. Whenever you're laying tile on a wood subfloor, you need to first install cement backer board. Backer board prevents leaks and water damage that could harm your flooring and the structure of your home.

What is the best surface to tile over?

You may tile over existing tile, painted or unpainted drywall, plaster and textured walls. But tiling over tile can add quite a bit of thickness, so make sure your wall can handle the weight. You should not tile over wallpaper, glossy surfaces, lead paint or plywood.

What goes between plywood and tile?

A plywood underlayment for tile should be 1/2- to 3/4-inch thick. What else can I use as an underlayment for tile floors? A cement backer board is a good underlayment for tile floors. Since it is a masonry product, it is less prone to deterioration than wood.

Will tiles crack on plywood?

Plywood and tiles expand and contract at different rates due to temperature and moisture fluctuations (especially in bathrooms and kitchens). Therefore, you should never apply tiles directly onto a plywood subfloor. If you do, your tiles will likely slip or crack in time.

Does cement board go over plywood?

If you lay tile on top of plywood, it'll expand over time, causing the tiles and grout lines to possibly crack and damage. The tile can't properly stick to wood as it can with concrete. Instead, lay a cement board on top of the plywood first or use a decoupling membrane.

Do I need to prime plywood before tiling?

If tiling on fibre-reinforced cement sheets, or plywood/chipboard, then we would always recommend priming the reverse side and edges with BAL Bond SBR. This helps protect the plywood from moisture penetration which could cause the board to swell.

How thick should plywood be under tile?

Use at least 1/2 in. underlayment-grade plywood, but I'd recommend 5/8 in. or ¾ in.

Which side of cement board do you tile on?

The smooth side is ideal for mastic applications, as it increases adhesive coverage. The textured side is ideal for mortar applications, as it enhances bonding and reduces tile slip. That said, mastic or thin-set mortar can be used on either side of the board without compromising performance.

What is better than cement board?

Mat-faced gypsum cover boards are increasingly used as a cement board alternative because they are lighter and easier to install. There are also performance enhancing benefits that mat-faced gypsum cover boards have over traditional cement alternatives.

Can I tile straight onto plywood?

Can you tile on plywood? Yes, but various considerations need to be made first. If the floor consists of sheets that do not support each other, it is necessary to ensure that each edge is fully supported underneath.

What is the best base for tiling?

Tile backer board is always a preferred ceramic tile underlayment.
  • Exterior Grade Plywood. Exterior plywood will also accept tiles and stone, without swelling up like interior-grade plywood. ...
  • Concrete Slab. A Concrete slab or concrete screed is a good tile underlayment. ...
  • Poured Concrete Screeds.

What surfaces can you not tile on?

Surfaces you should NOT put tile on
  • wallpaper.
  • bamboo.
  • laminate flooring.
  • wood flooring.
  • natural lime plaster (more common in older homes)
  • glossy surfaces/water-based paint.
  • lead paint.

Is it better to tile over plywood or backer board?

If you compare the two configurations using identical thinset mortars, tiles installed over cement backerboard have greater shear-bond strength than those that are installed over plywood.

Can I tile directly onto cement board?

Even though cement-fiber board can be externally used but it should be tiled over because of the extreme weather condition. Woods and cement-fiber boards should be only internally used for tiling over.

What is the best underlayment for tile?

Backer board is the most favored tile underlayment option when installing ceramic or porcelain tile. It comes in rigid panels that contain a blend of cement, fiberglass, and sometimes crushed glass particles.

Can you just screw cement board to the floor?

Embed the cement board in latex-modified thin-set mortar

Then spread thinset mortar with the flat side of a 1/4-in. notched trowel and use the notched edge to “comb” the mortar. Embed the cement board and screw it to the underlayment with special 1-1/4 in. cement board screws spaced every 4 in.

What happens if you don't prime before tiling?

If primers aren't used, there's a significant chance that your tiles could fail in the future - in other words, they could crack or come loose. There's a number of reasons why, including: If a dusty wall is unprimed, adhesive could just stick to dust and not adhere to the substrate itself.

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