Will epoxy resin waterproof plywood?

Author: Magnus Lang  |  Last update: Sunday, February 8, 2026

Epoxy Coating Method Epoxy forms a highly durable coating on plywood. Epoxy is a thermosetting resin that, when mixed with a hardener, is known for its strong adhesive properties, making it ideal for both binding materials and waterproofing.

Will epoxy make plywood waterproof?

Epoxy. Similarly to Polyurethane, epoxy also forms a highly durable coating over your plywood materials. Epoxy is a thermosetting resin that, when mixed with a hardener, is well-known for its strong adhesive properties. As such, this makes it ideal for binding materials as well as waterproofing.

What can you put on plywood to make it waterproof?

Epoxy Sealer: Epoxy sealer is an oil-based thick coat that penetrates wood pores, making plywood waterproof from the inside. It effectively blocks out moisture and air infiltration, preventing mould growth.

How much epoxy to seal plywood?

Estimating epoxy quantity and coverage

For a typical “flow coat” over a sealed surface, about 1/8″ thick, figure 0.75 pounds per square foot (a Group size A 105 Resin/207 Special Clear Hardener weighs 3.11 lb).

What is the best epoxy for plywood?

Thermal-Chem's #726 Armor Prime is a great choice. It is easy to work with as well as having a low viscosity to penetrate the wood and seal it off. You can pay special attention to the seams of each sheet and brush the primer over the seams, and if possible, place a 4” fiberglass tape over the wet epoxy.

Waterproof Plywood Deck - Liquid Rubber - Polyurethane Deck Coating Video

What is the cheapest way to seal plywood?

Another cheap method of sealant is a water-based paint. This sealing method is less standard than it's less long-lasting than the other methods. This paint may also need to be touched up more often, but it is cheap, quick and protects your plywood from moisture.

What is the best waterproof sealer for plywood?

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.

How to epoxy over plywood?

How do you apply epoxy over plywood?
  1. Begin by applying a seal coat.
  2. Four to ten hours after the seal coat, finish with a flood coat. A flood coat is poured onto the surface. It will flow and self level to 1/8 of an inch. Flood coat should be poured approximately 4-10 hours after the seal coat (6 hours is optimal).

What is the cheapest way to waterproof wood?

The most affordable way to waterproof wood is by starting with a natural wood oil and following with a coat or two of outdoor paint. Though more budget friendly in the short term, you will need to redo this method more frequently, as it is not as long lasting as, say, a pricier, high-quality sealant.

Can you seal plywood with fiberglass resin?

Pour a little bit of resin onto your plywood. Using a throw away brush or spreader, spread the resin until it covers the desired surface and there is a nice thin layer of resin on your plywood. Some people let this layer cure as a pre-coat. The pre-coat will seal the wood.

What is the most waterproof plywood?

Marine-grade plywood can be used as waterproof flooring and plywood cladding for spas and gyms. One of the most common uses of marine plywood is boat building. People use it to make different parts of the boat such as the hull. They take advantage of the plywood's excellent pliability and water-resistant properties.

Does Home Depot sell marine-grade plywood?

AB Marine-Grade Plywood 726540 - The Home Depot.

Can I use epoxy resin as waterproofing?

Water Based Epoxy resin can be used where concrete or masonry requires waterproofing and protection. It is applied in the same way as ordinary emulsion paint with the added benefit of application in damp conditions. Once dried Water Based Epoxy leaves a tough, non toxic, waterproof, easy to clean surface.

What kind of resin to use on plywood?

Epoxy is a far more suitable material. And there are some subsets of epoxy you might consider like “Surfboard resin”. This is water clear. ProSet epoxy is a very nice epoxy that is beautifully clear and nice to work with.

Can you use resin to waterproof wood?

One thing that we love about epoxy resin is that it leaves a clear sheen on top of wood, allowing its natural beauty to shine through. This glossy layer will also protect your wood from damage and provide a waterproof coating too.

How many coats of epoxy on plywood?

An epoxy project will typically only require one flood coating of epoxy resin. With a high-quality epoxy resin, this is usually more than enough to preserve your substrate surfaces for several years, without even needing reapplication.

Do I need to seal wood before epoxy?

Tip 2: Prep Your Wood: Sand, Seal, Tape, Level

Make sure you remove loose pieces of wood or bark to prevent them from floating away (and curing) into the epoxy. Sealing wood prevents air bubbles and absorption, which means you end up using less epoxy overall.

Will epoxy resin stick to wet wood?

Submarine Underwater Epoxy: Our underwater adhesive, will bond and cure underwater, or to wet wood. RotFix: Can be applied over damp wood at 20% moisture content or below.

How to waterproof plywood cheaply?

Use polyurethane varnish for dependable waterproofing, wood stain for weather-proofing, oil for a cheap, light sealant, or epoxy for a more thorough, durable finish. Sand your plywood before applying any sealant. Make sure your sealant of choice coats the plywood completely for total waterproofing.

How do you waterproof over plywood?

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.

What is the best durable finish for plywood?

The best product to seal plywood is epoxy sealer. Epoxy is highly effective for both sealing and waterproofing, as it forms a durable, moisture-resistant barrier that also strengthens the wood. It can also serve as an adhesive, enhancing the overall structural integrity of the plywood.

How to waterproof plywood with epoxy?

Methods for Waterproofing Plywood
  1. Mix the epoxy according to the manufacturer's instructions.
  2. Apply a thin, even coat using a paintbrush or roller.
  3. Allow the first coat to dry completely before applying additional coats.
  4. Sand lightly between coats for better adhesion.

How do you seal rotting plywood?

Once you've removed the crumbling wood, use a wet rot wood hardener and apply it to the wood with a paintbrush. Don't be afraid to lay it on thick and leave it to soak into the wood. When the hardener is dry, the rotten wood should be healthy again.

How to permanently waterproof wood?

Sealant. 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.

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