Waterproof plywood - DIY
Waterproofing plywood, is it possible? Yes, protecting plywood sheets and creating a moisture resistant barrier is possible. Before we jump into the solution on how to use plywood in damp or outright wet environments, it is useful to take a brief look at what plywood actually is, how it is made, and why it becomes problematic with exposure to moisture.
What is plywood?
Plywood is sheet material that consists of multiple layers – always an odd number – of wooden veneer. These veneers are glued crosswise with waterproof glue sealant or some type a glue sealant, depending project requirements. Boards with five or more layers are called multiplex, while three-layer boards are referred to as regular plywood. The veneers are dried to the proper moisture level and then pressed together with thermosetting resin under high pressure and temperature.
The glues used are binding materials known as polycondensative adhesives, commonly found in load-bearing timber structures. Because a multiplex board consists of several layers, it can incorporate different types of wood. Often, the outer plywood surface layers are of more expensive types of wood, and the inner layers use more affordable materials. At the end of production, the large plates are cut to size (or standard sizes) and possibly sanded.
Thanks to this way of construction, multiplex has a number of advantages as a wood composite construction material. It makes efficient use of wood, including lower quality or alternative types of wood, especially in the core. Due to the symmetrical structure – where both sides mirror the center layer – plywood suffers fewer distortions than solid wood. In certain directions, plywood creates even greater strength than regular timber.
Multiplex is used for a large number of applications, often with added layers tailored to the specific type of plywood required. For example, there is pressure treated plywood for use in the construction of buildings. Plywood used in visible applications can have a layer of veneer, and you also have marine plywood for concrete molds and outdoor projects. There is also special plywood for use in aircrafts and extra strong, bullet-resistant plywood.
Why is moisture a problem?
Untreated wood veneers are not water resistant, and although the glue sealant may be waterproof, the wood fibers themselves are sensitive to prolonged moisture exposure. Prolonged water contact can cause plywood to warp, develop mold, or rot. The plywood surface may also deform or become damaged.
Does waterproof plywood exist?
Plywood is composed of veneer sheets, and because untreated timber is not waterproof, plywood also is not. However, plywood WBP is available. Plywood WBP stands for Water Boiled Proof and is suitable for use in humid environments. However, this only offers general moisture resistance. For better protection, an additional protective coating or waterproof sealant is needed.
Fortunately, there is a solution, just like solid wood, multiplex and plywood can be protected from moisture. The solution is called Woodcon.
How to waterproof plywood with Woodcon
Woodcon is an impregnating wood oil made from natural wood oils that deeply penetrates the wood fibers that makes timber, and also the timber layers in plywood, water-repellent. Instead of applying a clear or pigmented film to the surface, Woodcon focuses on repelling direct water exposure and light moisture – without the typical sheen of outdoor latex paints or latex paint varnishes. This keeps the natural grain visible and maintains the rustic look. After treatment, the plywood surface remains dry and protected against mold, algae, moss, woodworm, and termites.
You can follow these steps:
1. Surface preparation: sand with fine grit, remove dust, dirt, and debris.
2. Fill imperfections (like holes or cracks) using wood filler and a putty knife for a smooth finish.
3. Sealing edges: pay extra attention to the edge finish.
4. Apply a thicker or thinner coat of Woodcon using a brush, roller, or sponge, let it dry completely as per the manufacturer’s instructions carefully.
5. Optionally apply multiple coats for multiple layers of protection.
6. Follow the manufacturer’s instructions regarding drying time, temperature, and number of recommended coats.
7. For added strength, consider a polyurethane coating or epoxy coatings as a durable option in heavy-duty situations (e.g., boat building, outdoor structures).
The effectiveness of Woodcon can be contributed to the fact that it does not create a separate protective layer on the plywood, such as other wood protection solutions, but it actually impregnates the wood. It is heavy duty waterproofing without a layer that unlike latex paint or some epoxy coatings does not peel. A great alternative to water resistant paints that offers a longer lasting waterproof treatment and protection against UV damage (uv damage). Woodcon creates a transparent water-repellent layer in and on the wood surface, and will never peel or break off. Because Woodcon fixes itself around the wooden fibers, it creates a highly durable coating with excellent water resistant properties.
Woodcon is not only the perfect solution for waterproofing plywood and timber from outdoor structures or wood restoration projects. After treatment with Woodcon, even cane and rattan can be used in a wet or damp environment. So rattan garden furniture, thatched roofs, and any other cane or rattan applications you want, Woodcon allows for it.
How to waterproof multiplex with Woodcon?
Woodcon is easy to use for do-it-yourself projects with a brush, roller, sponge, or low pressure spray and ideal for edges, joints, and plywood sheets. While it is nontoxic and not damaging to flora and fauna. Woodcon is non-flammable, and it cannot explode. Rather, Woodcon even has a fire-retardant effect on wood and plywood. Woodcon is available in various sizes: from 1 to 25 liters, covering approx. 88 ft² per liter, depending on the wood’s porosity (surface, natural wood oils).
Woodcon
- Woodcon makes every wood-surface waterproof and water-repellent without discoloring or changing the surface of the wood.
- 15 year guarantee
- Depending on the porosity of the wood, 1 liter is sufficient for an average 88 ft²
- Available in 1 / 2,5 / 5 / 10 / 25 Liter.
