Can Strand Board Be Used Outside?

Are you contemplating using plywood for an outdoor project? It's a common question among homeowners and DIY enthusiasts. Strand board, a type of plywood, seems like a practical choice due to its durability and affordability. But can strand board be used outside? The answer is a bit more complex than a simple yes or no. Let's delve into the details.

The primary concern when using any material outdoors is its susceptibility to weathering. Strand board, made from several layers of(longitudinally oriented) wood veneer, is indeed robust. However, it's not inherently weather-resistant. So, while it can be used outdoors, it requires careful consideration and preparation.

The Composition and Weather- Resistance of Strand Board

Strand board's strength lies in its composition. The longitudinal grains make it robust and able to withstand significant pressure without breaking. However, this structure also means it's more vulnerable to moisture and temperature changes, which can cause it to expand, contract, and even warp over time.

Moreover, the adhesive used to bind the veneers together can degrade when exposed to extreme temperatures and moisture, further compromising the board's integrity. Thus, while strand board can temporarily endure outdoor conditions, prolonged exposure can lead to significant damage.

Weathering Effects on Strand Board

Exposure to sun, rain, and snow can cause strand board to crack, discolor, and rot. The UV rays from the sun can break down the lignin in the wood, making it more susceptible to water damage and insect infestation. Direct contact with moisture can cause the board to absorb water and swell, then shrink when it dries out, leading to cracks and warping.

Furthermore, when the temperature drops, the moisture inside the wood may freeze and expand, exerting additional pressure on the wood fibers and causing internal damage. This cycle of expansion and contraction can eventually lead to the board's failure.

Treating Strand Board for Outdoor Use

If you decide to use strand board outdoors, treating it with water-resistant sealants or preservatives can extend its lifespan. Several options are available, including waterproofing paint, varnish, or even pressure-treated wood preservatives. These treatments can help protect the wood from moisture and UV damage.

However, it's important to note that no treatment can fully protect strand board from weathering. They can only delay the process. As such, using treated strand board outdoors should be a last resort, and you should continually monitor the boards for signs of damage and replace them as needed.

Alternatives to Strand Board for Outdoor Use

Given the challenges of using strand board outdoors, consider these alternatives that are more weather-resistant:

• Pressure-treated plywood: Made specifically for outdoor use, pressure-treated plywood is infused with preservatives that make it resistant to rot, decay, and insect damage.
• Composite materials: Made from a combination of wood fibers and recycled plastics, these materials are durable, weather-resistant, and low-maintenance.
• Cedar or redwood plywood: Naturally resistant to rot and decay, these woods are a good choice for outdoor projects. However, they're more expensive than other options.

Each of these alternatives has its pros and cons, so the best choice depends on your project's requirements and budget.

Tips for Using Strand Board Outdoors Temporarily

If you must use strand board outdoors, follow these tips to minimize damage:

1. Keep it covered: Whenever possible, keep the strand board covered to protect it from direct sunlight and rain.

2. Provide adequate ventilation: Ensure the board can breathe to prevent moisture buildup. This is especially important in humid climates.

3. Monitor for signs of damage: Regularly inspect the board for signs of warping, cracking, or other damage. Replace it as soon as you notice any problems.

In many cases, it's best to avoid using strand board outdoors altogether. While it can be used temporarily or in covered outdoor structures, it's not a long-term solution. Opting for more weather-resistant materials will save you time and money in the long run.