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.
The best thing about an epoxy sealant is that you only need one layer to get the best waterproof protection for plywood.
Hard wax oil is an excellent choice for coating plywood, and is the finish that we use and recommend. The main point of difference is that it protects wood from the inside out, unlike most coatings which form a film on the surface only.
You can seal a subfloor using a sealant specifically designed for subfloors, such as a penetrating sealer or a moisture barrier. Penetrating sealers are typically made from a wax or oil-based formula that soaks into the wood, protecting it from moisture and rot.
Glue down vinyl planks do not need waterproofed subfloors, but if you install vinyl as a floating floor, you should waterproof the subfloor for maximum protection.
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. For outdoor use, consider marine-grade sealants for extra durability.
Epoxy is considered the most robust and effective option for ensuring plywood's longevity, especially in high-moisture environments.
Layering for Extra Protection. For floors that experience heavy foot traffic, layering multiple coats of water-based polyurethane can provide extra protection. Aim for at least three coats, allowing each layer to dry thoroughly before applying the next.
The most common ways of waterproofing plywood include treating the wood with epoxy, waterproof glue sealant, or polyurethane prior to installation.
Cement Board:
Often used as a subfloor material for tile installations, cement boards provide a stable, water-resistant base that helps protect the floor against moisture.
Yes. Hardwood flooring is quite sensitive to moisture and it's always worth adding a moisture barrier during installation. It is a necessity with concrete subfloors and damp areas, but water-resistive underlayments should be considered with other subfloors as well.
The underlayment sheets usually run in the same direction as the plywood subflooring, but it is critical that the seams of the underlayment are offset from those in the subflooring, so the underlayment bridges over the subfloor joints.
How do you seal untreated plywood? To waterproof plywood, an epoxy, waterproof paint, oil, varnish, latex or PVA can seal the wood for both indoor and outdoor use. These can come in either a paint-on or spray form, and they all bond easily to the wood to seal it and protect it from moisture.
Make sure to sand the polyurethane between coats.
Many customers choose water-based polyurethane as a greener alternative to oil-based finishes. Water-based poly's low VOCs and fast dry times make the application process less of a hassle for homeowners. If homeowners are open to the idea of vacating for an extended period, oil-based poly is an option.
If you're short on time, here's a quick overview: Composition: Polycrylic is water-based, while polyurethane can be oil-based or water-based. Application: Polycrylic applies in thin coats and dries quickly; polyurethane takes longer to dry.
The best overall varnish is Ronseal Diamond Hard Floor – it's durable, available in a range of colours, can be used on floors that have previously been varnished, and a second coat can be applied two hours after the first.
To stain plywood to resemble cherry, walnut, or other hardwoods, sand and clean the plywood, choose a matching wood stain, apply a pre-stain conditioner for even absorption, brush on the stain following the wood grain, wipe off excess, and seal it with a clear finish for protection and the desired sheen.
Yes, sealing the plywood subfloor ensures better adhesion for peel-and-stick tiles and prevents moisture damage. Use a primer or sealer designed for flooring to create a smooth, even surface. This also extends the lifespan of the tiles by enhancing their bond.
Epoxy: Coat the plywood with epoxy resin for strong water resistance. Waterproof glue sealant: Apply a Type-A waterproof glue sealant for durable protection. Polyurethane: Seal the surface with polyurethane to block moisture.