What Exactly Is Pressure Treated Plywood?
Pressure treated plywood undergoes a specialized pressurized treatment that enhances its resilience, reducing susceptibility to rot, water damage, mold, and insect infestation. This treatment increases the wood’s density, fortifying it against external elements. The process involves using pressure to infuse chemicals into the wood, ensuring even distribution and controlled application. Consequently, the treated plywood exhibits improved quality and strength due to the uniform penetration of the chemicals.
Vinawood offers pressure treated plywood in 1/2 and 3/4 thickness. The sheets measure 4′ x 8′. The sheets have a grade of BC or CDX. The BC grade indicates the sheets to have one good side. The CDX indicates that the sheets will have knots on both sides. Due to the moisture content we are not able to cut these sheets to your specification.
How Exactly Is Pressure Treated Plywood Manufactured?
As I had mentioned before, the pressure treated plywood procedure involves utilizing pressure to introduce chemicals uniformly into the wood. This process occurs within a specialized cylinder chamber known as a retort. Once inside the retort, the machine will seal and depressurize to get as much air out as possible from the wood’s cells. Subsequently, the chamber is flooded with chemicals, and pressure is applied for a special duration.
Pressure treated plywood is categorized based on its intended use, determining its “retention level” or the quantity of chemicals retained post-treatment. Higher retention levels necessitate longer chamber exposure.
Upon completion of the treatment, the pressure treated plywood is set aside to fully dry before distribution. Although this drying period can be time-consuming, it contributes to the wood’s enhanced strength
Pressure treated plywood was made with arsenic at one point. It’s hard to imagine who approved that for residential use! But don’t worry today’s pressure treated plywood is completely safe.
Before 2004, pressure treated plywood was being made with something called Chromated Copper Arsenate (CCA) that helped to prevent the wood from rotting. CCA contains arsenic, chromium, and copper and was used in the United States starting in the 1970s.
The Environmental Protection Agency phased it out in 2003 because of the dangers that the chemicals presented and the rising public concern of arsenic-contamination in children’s playgrounds. The EPA worked with the wood manufacturers to remove wood with CCA from any residential use. It can still be used in other commercial products that humans will have little contact with it.
They have since kept a close eye on all the remaining ways to pressurize wood. This is another reason why it is important to only buy wood that has a regulated stamp of approval.
What Are the Usages of Pressure Treated Plywood?
Pressure treated plywood is usually reserved for wood that may come in to contact with excessive moisture. This wood can be used residentially for external wood such as, decking, fences, docks, or any other wood that would have prolonged exposure to water.
It can also be used in other industries as well. Construction industries will use pressure treated plywood in bridges, guardrails, or any other projects that need to be outdoors and withstand the elements.
There is a difference between wood that is above the ground and what touches the ground, or ground contact wood. Wood that will have ground contact will have to go through a longer process, so that it has twice the level of chemical retention compared to non-ground contact wood.
Types of Pressure Treated Plywood
- Borate: Borates are composed of sodium salts that are then used in a water-based solution. This chemical helps to keep the color of the wood and protect against mold, insects, and general breakdown. Since it is mixed with a water-based solution, it can start to leak out in rainy or wet areas. Best for dry locations.
- Alkaline Copper Quaternary (ACQ): This is one of the most environmentally friendly options of the types of pressure treated plywood. It is made with soluble copper and quaternary ammonium alkyl. Protects against mold, insects, and general breakdown. It does change the color of the wood to a darker brown tone. There is no arsenic or chromium contained in this preservative.
- Noncombustible Wood: This is wood that has been treated with a fire-retardant chemical before being pressurized. This is to help with flammability but does not completely take away risk. Can be used residentially or commercially, but not advised to be painted because it may affect the way it performs.
FAQ
Is There a Distinction Between Pressure Treated and Heat Treated Plywood?
Absolutely no, pressure treated plywood and heat treated plywood do not describe the same product. But these two types of treatment do have some crossover.
Heat treated plywood is wood that is placed in a kiln and is exposed to high heat until the internal temperature of the wood reaches 133 degrees for thirty consecutive minutes. This should not be confused with kiln drying. Kiln drying uses lower temperatures for a longer period until the moisture level is under nineteen percent. Kiln drying is a longer process that is specifically used to lower moisture levels in wood without warping or bending. These two are similar in the way that they both make use of a kiln, but they are unique in what they do to the wood.
Heat treatment is used as a sterilization process and does not change the wood’s density or other characteristics the way that kiln drying does. Heat treatment ensures compliance with the ISPM 15 regulations that state wood must be sanitized before import or export.
This process kills off insects and other pathogens that might be contained in the wood. The Pinewood Nematode and the Asian Longhorned Beetle are the most commonly found insects in wood pallets. This process helps to eliminate them and keep wood products healthy. ISPM 15 requires all hardwood and softwood to be treated. The wood will garnish a stamp that states that it has met all requirements. This is crucial if you need export lumber. So far, 130 countries have adopted this standard, including the United States.
As you can see, pressure treated plywood and heat treated plywood are different things entirely. But pressure treated plywood has most likely gone through a heat treatment before it continues its own unique process.
Comparing Marine Plywood with Pressure Treated Plywood: Which Triumphs?
Sometimes, when choosing plywood for your work, you may wonder if you can use pressure treated plywood instead of marine plywood for coring, so i will give you a comparison to illustrate why these plywoods are not interchangeable.
| Marine plywood | Pressure Treated Plywood |
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-Common plywood that has been pressure treated with chemicals.- This treatment prevents the wood from decaying or rotting.
-Can also discourage insect damage. -Pressure treatment with chemical compounds does not waterproof the plywood. -Continuous exposure to water will leach the preservative chemicals from the wood. -Often made with soft wood to enable the penetration of the chemicals. -Softer woods will also allow for the penetration of water. -Does not have the additional plies to add strength and durability. -Does not eliminate all gaps or voids. |
So the winner is marine plywood which is specifically manufactured to stand up to the harsh marine environment. In fact, marine plywood will work effectively for any plywood project. The materials used in its construction are specifically chosen to assist in making it as water resistant as possible. Pressure treated plywood is usually regular softwood and will absorb moisture very easily.
Reputable suppliers know the difference between marine-grade plywood and high grades of traditional pressure-treated plywood. At Vinawood, our clients can trust the materials we supply for their projects because we understand the importance of every job. Vinawood is known as a leading provider of industrial wood and packaging solutions. Specializing in cut lumber needed for pallets, crates, skid parts, fully assembled custom pallets, integrated packaging solutions, and other services that can be tailored to each individual customer.
With 14 different locations, we have the ability to meet the needs of our customers quickly and efficiently nationwide. Reach out to one of our knowledgeable team members today to learn how we can help your business!
