To PVA/Seal ply before tiling floor tiles

Hi there, If you are 100% using ply board then I would seal the ply with acrylic-based primer. However I would recommend that you use a cement based backer board instead.

The answer is NO to the whole question. The new British standard law says you should not lay tiles on any ply wood

Personally I’d put a membrane down and tile onto that, if you pva the ply the adhesive will only stick to that and not the floor!

Because ply reacts to moisture, and temperature variations. Also check for movement in 12mm ply. You might go thicker. Overboard the ply with a cement board. Use correct screws for that. Then install tile.

When it comes to laying 600x600 Glazed Porcelain ceramic floor tiles on a 12mm plywood floor in a small bathroom, it's essential to ensure proper preparation to achieve a long-lasting and successful installation. Regarding whether the plywood floor should be sealed before tiling, here's some guidance: Sealing the Plywood Floor: Sealing the plywood floor is generally recommended to create a moisture barrier and enhance the durability of the installation. Sealing helps prevent moisture from penetrating the plywood and potentially causing issues such as warping or deterioration over time. By sealing the plywood, you provide added protection and help maintain the integrity of the tile installation. Recommended Sealant: To seal the plywood floor, it's advisable to use a high-quality penetrating sealer specifically designed for wood or plywood surfaces. Look for a sealer that is suitable for moist environments and provides excellent water repellency. There are various sealant products available on the market, such as polyurethane or epoxy-based sealers. It's essential to choose a product that is compatible with plywood and suitable for tile installations. Application Process: Before applying the sealer, ensure that the plywood surface is clean, dry, and free from any dust or debris. Follow the manufacturer's instructions for the specific sealer you choose, as application methods can vary. Typically, you will need to use a brush, roller, or sprayer to evenly apply the sealer onto the plywood surface. Allow the sealer to dry thoroughly before proceeding with the tile installation. Professional Advice: To ensure the best results and to address any specific considerations related to your bathroom and tile installation, it's always recommended to consult with a professional tile installer or a knowledgeable specialist at a reputable tile supplier. They can provide personalized guidance based on your specific project requirements, local conditions, and the specific products you intend to use. Remember, proper surface preparation is crucial for a successful tile installation. Sealing the plywood floor can help protect it and enhance the longevity of your tile project. By using the appropriate sealer and following the recommended application process, you can create a solid foundation for your 600x600 Glazed Porcelain ceramic floor tiles in your small bathroom.