You can install tile on plywood, but you must take a few precautions to prevent the plywood from cracking the tile. The best direct underlayment for tile on plywood is
You would normally install backer board over the plywood before installing the tile. Backer board provides a firm non-flexing surface for the adhesive and tile.
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. If the tiles are small (no larger than 400mm by 400mm) an improved flexible (S1) tile adhesive is suitable.
The most common ways of waterproofing plywood include treating the wood with epoxy, waterproof glue sealant, or polyurethane prior to installation.
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.
Traditionally, you would use modified thinset to adhere tile to a plywood subfloor. Due to its absorbent and porous nature, plywood is capable of sucking the moisture out of unmodified thinset.
When tiling onto plywood overlaid timber we recommend using a flexible adhesive (S1) such as Topps Tiles Rapid Set Flexible, BAL Rapid-Flex Fibre or BAL Flex Fibre. For a sustainable and more eco-friendly option, Regener8 is a great adhesive available in S1 rapid and standard setting bags of 20KG (white and grey).
Epoxy. Epoxy sealers are usually the preferred method of sealing and waterproofing plywood. Epoxy doubles as an adhesive, which gives an additional layer of strength plus protection for the wood, helping it to last even longer. It can double as a primer too, if the wood is to be painted after sealing.
Have you previously felt uneasy about using plywood products in bathroom and kitchen designs? Well now you don't need to be. Plywood is as durable as it is beautiful in bathroom and kitchen settings when pre-finishing, sealing and hard-wax oil coating are completed.
When applying tiles directly onto plywood without a seal, the adhesive won't bond and will get stuck in the ply. In addition, when using a non-flexible adhesive, you will likely struggle to get your tiles to stick to plywood.
Underlayment is the material placed on top of the subfloor that assists in the installation of the tile or other type of flooring.
A primer for tiling is especially effective on porous surfaces such as plasterboard or plywood. It seals the surface, prevents moisture absorption, and ensures effective adhesive bonding. PVA, a general-purpose adhesive, may not offer the same level of protection and could lead to adhesion issues.
Step-by-Step Guide on How to Prep for Tile Floor
For concrete floors, clean the surface thoroughly, repair any cracks with a suitable filler, and use a self-leveling compound to even out any uneven spots. This is how to level a concrete floor before tiling.
A polyethylene uncoupling membrane like Schluter Ditra releases the bond between plywood and tile mortar, allowing each surface to move independently. Uncoupling tile membranes prevent moisture migration. Membranes are lightweight and easy to work with but expensive.
However, while plywood is now not recommended as a background for direct wall tiling, it can still be used as a structural board when overlaid with a suitable tile backing board, particularly where installation of mechanical fixings is required e.g. for mesh backed natural stone where it is not possible to remove 75% ...
Latex-based or polyurethane-based paint is one of the most accessible forms of waterproofing plywood. There are plenty of colours to choose from, which can be applied using a spray gun or painted with a roller. You must apply two to three coats of paint for maximum effectiveness.
Apply a Waterproof Membrane:
To provide an extra layer of protection, it's advisable to apply a waterproof membrane on the entire surface that will be tiled. This membrane serves as a barrier against water penetration and helps prevent any potential leaks.
While not the most durable option, a common method for waterproofing plywood is using water-resistant paints, such as latex paint varnishes. Applying latex paint over plywood creates a protective layer on the surface, preventing moisture from seeping into the wood.
Sealant is a popular choice for waterproofing wood, offering long-lasting protection by forming a waterproof barrier on the wood's surface. Sealant is one of the closest options for how to permanently waterproof wood. Unlike oil, sealants provide both strength and protection.
The cheapest way to waterproof plywood is to use a waterproof sealant or paint. Applying a coat of epoxy sealant or water-based polyurethane provides effective protection against moisture. Another budget-friendly option is to use oil-based paint or varnish, which can also seal the wood.
To waterproof plywood floors before tiling, install an appropriate waterproof uncoupling mat or waterproof tile backer board. They can then be tiled as normal using an appropriate ARDEX Cement-Based Tile Adhesive.
I would recommend gluing and screwing a ¼” thick Hardiebacker cementitious board to the plywood and then adhering the ceramic tile with a thin-set dry set mortar that meets ANSI A118. 4 or ANSI A118. 15.