On average, pressure treated plywood can last anywhere from 20 to 30 years or more when used in outdoor applications. Proper installation, regular maintenance, and protection from prolonged exposure to moisture and sunlight can help extend the lifespan of pressure treated plywood.
Many manufacturers boast a lifespan of treated wood up to 40 years with proper care. That being said, regularly maintained untreated wood can last forever.
Plywood can typically withstand rain exposure for a day or two without significant damage, depending on the type of plywood and the severity of the rain. However, long-term exposure can lead to serious damage such as warping, cracking, or rotting.
Outdoor plywood, treated to withstand weather exposure, provides a reliable material choice for fencing and gate construction. Its inherent strength and resistance to moisture make it suitable for withstanding outdoor elements while maintaining structural integrity over time.
However, as with all other wood products, plywood should be protected from moisture and especially water, as it will soak that water up. A small amount of rain will not ruin plywood. A few showers of rain or a storm on your plywood will be ok as long as it is for only an hour at the most.
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.
Generally, if common plywood gets wet for an extended period of time, it can swell and lose shape which eventually leads to the layers of wood splitting apart. This often occurs when plywood is stored outside for even a short timeframe before a project begins.
If you are storing plywood outside, you need to keep it elevated at least 6 to 12 inches off the ground. This is necessary in order to avoid the bottom pieces of plywood coming in contact with moisture from the ground be it rain or water from other sources.
Pressure treated wood can last for up to forty years or more. Precisely how long it will last depends on the chemicals used in the pressure treatment, the project type, the wear and tear the wood will endure, the species of wood, the amount of exposure to harsh wet environments and how well it is maintained.
This damage resistance makes pressure-treated plywood the best choice for exterior projects. Depending on your application, look for pressure-treated plywood rated for either ground contact or above-ground use. Plywood sheets generally come in 4-foot-by-8-foot boards.
This includes oxygen, temperature (between 65 and 95 degrees), moisture (20% for dry rot and 50% for wet rot), and food (wood). In general, dry rot can appear between 7 and 10 days after the wooden element has received enough dampness. If the spores are older, they may take longer to germinate.
Plywood falls into one of four categories: exterior, exposure 1, exposure 2, or interior. But what do these labels mean? Exterior plywood has a full waterproof bond/glue in between its layers and is best suited for projects that will be constantly exposed to moisture and weather.
With the advantage of being manufactured 100% from natural plantation wood, plywood has relatively high durability and a lifespan of up to 35 years.
Untreated wood, without any protective coating, generally lasts no longer than two years outside. However, certain types of wood, such as cedar, redwood, cypress, and white oak, are more durable and can last for years when exposed to the elements.
Why Should you Waterproof Plywood? Like other natural materials, untreated plywood is susceptible to rot caused by moisture and water, creating a breeding ground for fungus or mould within the board. As the wood rots, it affects the board's integrity, which can cause it to break down over time.
The lifespan of pressure treated plywood outside can vary depending on several factors, such as the quality of the treatment, environmental conditions, and how well the plywood is maintained. On average, pressure treated plywood can last anywhere from 20 to 30 years or more when used in outdoor applications.
A pressure treated fence post can generally last 10 to 25 years.
How is Plywood Used Outdoors? Exterior plywood is weather (and water) resistant, so it's strong enough to be used outside and also in areas that are exposed to water and humidity, like a garage. This type of plywood, often made from Douglas fir, is made stronger by adhering its layers with a waterproof glue.
Contrary to what its label suggests, “Exterior” rated plywood does not have any rot resistant properties. Rather the term “exterior” refers to the panel's bond classification and type of adhesive used when manufacturing the plywood.
Treated plywood can last for several years outdoors, depending on factors like climate and maintenance. Apply a weather-resistant finish and monitor for signs of decay or damage.
In general, when wood is continuously exposed to moisture and favorable conditions, it can start to show signs of rot in as little as a few months to a few years. In more extreme cases, untreated wood can completely decay within a decade.
The most durable and effective option to waterproof plywood is by applying Type-A waterproof glue sealant. Most reputable plywood suppliers will already adopt this approach and as such, it is the type of sealant you will find on marine and heavy-duty plywood.
Moisture is the primary factor that promotes mold growth on plywood. This moisture can come from various sources, such as leaks, condensation, or high humidity levels.