Is External Plywood Suitable For Outdoor Flooring?

Exterior plywood is a type of weather-resistant plywood that is suitable for outdoor use, especially in areas exposed to water and humidity. It is made from Douglas fir and is made stronger by adhering its layers with waterproof glue. The best type of plywood for outdoor projects is marine grade or ACX plywood, which is designed to withstand harsh weather elements outside.

There are various types of exterior plywood, such as CDX, ACX, marine, and pressure treated, and their pros and cons. The wood is more robust, and the waterproof glue binds the layers together. Outdoor plywood is suitable for all types of construction, including decks, sheds, outdoor siding, and outdoor furniture.

However, it is important to consider factors such as grade, thickness, finish, and fire resistance when choosing the right exterior plywood for your project. CDX plywood can be used for flooring in an outdoor shed but may not provide long-term durability if exposed to moisture. Marine plywood is suitable for outdoor use due to its water and rot resistance. Other plywood types might require additional treatment for outdoor applications, such as properly sealing the wood or even a coat of outdoor paint.

Both marine plywood and exterior plywood are designed to be used externally, using an A-bond glue to stand strong. However, even if you use exterior rated plywood, you will still have severe warping, strength, and rotting issues.

In conclusion, exterior plywood is a versatile and durable option for outdoor construction, making it suitable for various outdoor applications. However, it is essential to choose the right type of plywood based on factors such as construction, cost, appearance, and fire resistance.

Can I use plywood for outdoor flooring?

Marine plywood is ideal for outdoor use due to its water and rot resistance. Other types may require additional treatment. Plywood is an engineered wood made by gluing together thin veneers, and the adhesive used and wood veneers can significantly impact its performance, durability, and suitability for outdoor environments. External grade plywood, also known as “CDX plywood”, is designed for outdoor use and is made from durable wood species like spruce, pine, or Douglas fir.

It undergoes a pressure treatment to enhance moisture resistance and is commonly used for outdoor structures like sheds, fences, and exterior sheathing. However, even exterior grade plywood is susceptible to moisture damage, such as warping, swelling, and delamination if not properly sealed and maintained. To prevent moisture absorption, it is recommended to apply a high-quality exterior paint or sealant to all sides and edges of the plywood.

What is the best way to waterproof exterior plywood?

Epoxy sealers are a commonly utilized method for the sealing and waterproofing of plywood.

Does exterior plywood need to be pressure treated?

Outdoor wood should be pressure-treated according to the AWPA, as its use determines the necessary treatment. For indoor or outdoor projects involving humans or pets, extra precautions are necessary. The chemicals in pressure-treated lumber are pesticides, so handling them with the same precautions as hazardous materials is crucial. Wearing gloves and face protection is recommended, as sawdust from cutting the wood can be irritant. Painting exposed wood surfaces with water-repellent finishes, paint, or stain can protect skin if leaning or kneeling on the sides.

How to make plywood last forever outside?

Plywood is not naturally waterproof and needs to be treated before installation, especially for outdoor projects or high-moisture areas. Proper waterproofing extends the plywood’s lifespan, reduces the risk of rot, and preserves its natural wood appearance. To ensure complete protection, seal all edges when waterproofing plywood. Plywood consists of multiple thin wood layers or veneers glued together, which can become entry points for water, leading to swelling, delamination, and mold growth.

To protect plywood from rain and snow, consider using water-resistant paints like latex paint varnishes, Type-A waterproof glue sealant, polyurethane, and wood oils. For example, the plywood lid of an outdoor storage bench delaminate after water from overflowing gutters seeped onto its front edge, dissolved the wood filler between the trim and plywood edge, and penetrated the plywood layers.

How do you seal plywood for outdoor use?

Epoxy sealer is an oil-based coating that penetrates wood pores, making plywood waterproof from the inside. It blocks out moisture and air infiltration, preventing mold growth. Varnish is a thin resin that creates a hard, protective coating, enhancing the aesthetics of plywood surfaces. Water-based paints can be used to waterproof outdoor plywood, but may require touch-ups or repainting every few years. Drying oil, such as Tung oil, is an excellent choice for outdoor use, providing an effective protective coat while allowing natural flexibility and moisture retention.

Liquid latex is an easy-to-apply option for sealing plywood, creating a protective layer that seals pores and preventing water infiltration. Prioritizing safety is essential when applying these waterproofing solutions, and personal protective equipment (PPE) is essential. All necessary materials, including a high-quality waterproofing solution, a brush or roller, and a clean container for mixing, should be prepared. Clean equipment immediately after use and store the remaining solution properly to ensure its longevity and effectiveness for future use.

Can plywood be used externally?

Exterior plywood is a durable and weather-resistant material that is suitable for use in a variety of outdoor applications, including furniture, sheds, and roofing. Its strength and stability, even in wet conditions, make it an ideal choice for these applications. The versatility and ease of use of this material make it an ideal choice for a variety of projects, as it can be cut and shaped to fit any project and comes in a range of thicknesses and sizes to meet different needs.

What kind of plywood can be used outside?

Exterior plywood is a weather-proof material used for outdoor applications, made from multiple layers of wood veneers bonded together using phenolic resin. This glue hardens to form a crystalline substance, making it resistant to moisture and humidity. Manufacturers use hoop pine, spruce, mahogany, Douglas fir, birch, oak, and maple wood, and treat veneers with preservatives to withstand harsh weather conditions like strong winds and heavy rain.

How long will plywood last outside?

Pressure treated plywood can last 20-30 years or more in outdoor applications, depending on factors like treatment quality, environmental conditions, and maintenance. It can withstand rain and other elements without significant damage due to its resistance to moisture, rot, and decay. However, prolonged exposure to standing water or constant moisture can lead to deterioration over time. Proper drainage and ventilation are essential to prevent water from pooling on or around the plywood. Regular maintenance, such as applying a water-repellent sealant, can also prolong its lifespan. Marine grade plywood is also waterproof, but its lifespan depends on proper drainage and ventilation.

Is exterior plywood waterproof?

Exterior plywood is designed to resist moisture and weather elements but is not fully waterproof like marine plywood. Marine plywood can endure constant water exposure without warping or delaminating, making it suitable for prolonged water contact situations. To waterproof outdoor plywood, lightly sand the surface, choose a waterproofing product like epoxy, waterproof paint, oil, varnish, latex, or PVA, apply the waterproofing layer using a brush, roller, or spray, let it dry, and apply 2-3 additional coats for better protection. This process ensures the plywood remains resistant to moisture and weather elements.

How do you keep plywood from rotting outside?

Epoxy sealant is a popular choice for outdoor projects due to its one-layer waterproof protection. Plywood, a cheaper and more durable material, is made by gluing and compressing veneer layers in opposite directions. Although not fully waterproof, it can be produced to extend the life of furniture. Plywood is used in high-moisture areas like bathrooms, kitchens, and outdoors, making it a visually appealing choice for furniture. However, it is essential to seal plywood to prevent water damage and ensure its longevity.

Can exterior grade plywood get wet?

Exterior plywood, often made from Douglas fir, is weather and water resistant, making it suitable for outdoor use in areas exposed to water and humidity. It can be used on decks, walkways, sheds, outdoor shelving, and outdoor structures like gazebos, benches, or planters. There are various types of exterior plywood, with the most common being CDX or ACX. The construction grade is indicated by an X, with A being a premium grade for high-end uses and CDX being a more affordable option.

The plywood layers can be made from veneers, high-density hardwood, or light hardwood. While it may not be visually appealing due to visible knots or blemishes, some types have cleaner appearances, making them ideal for projects requiring aesthetic appeal. The construction grade is indicated by the first two letters, indicating the plywood’s construction grade.