Many people use pressure-treated plywood when constructing their subfloor. It acts as a base that provides strength and support to the main floor so that you can walk comfortably on the top.
Can I Use Pressure Treated Plywood for Subfloor? You can use pressure treated plywood for the subfloor because it provides better resistance against decay, moisture, and pests. Moreover, it is fire resistant, requires low maintenance, and remains intact for longer. You can get plywood sheets in every size that are easy to maneuver. Put the wooden pieces over an insulation sheet of polyurethane and foam that helps resist vapors from the ground. Fix them on the sleepers present at a distance of 10 to 12 inches away from each other by flooring screws after drilling holes.
Different types of material are used for constructing a subfloor, like OSB (oriented strand board), plywood, and concrete material.
Many people add non-treated wood sheets while constructing a subfloor in their houses without knowing the benefits of treated wood.
Non-treated woods harbor the growth of insects and molds and promote the decaying process.
Therefore, you can prefer treated plywood over the natural one that makes the floor resistant to degradation.
- 1 What is pressure treated plywood?
- 2 Why would you use pressure treated plywood for the subfloor?
- 3 How to use pressure treated wood for subfloor?
- 4 What are the disadvantages of using pressure treated plywood on the subfloor?
- 5 What should be the thickness of the pressure treated plywood subfloor?
What is pressure treated plywood?
It is a wood that is treated with chemicals to improve durability and resistance to environmental stress.
Moreover, it contains lesser moisture content, making it suitable for subflooring and exterior uses. The CDX plywood is considered better for construction because it has three layers.
The manufacturers usually treat an oak, cedar, or pine plywood with a chemical solution containing preservatives like copper azole and amine copper quat.
The solution enters the lumber material when applying high pressure after depressurizing a tank to remove air. It remains inside the tank and then dries out after removing.
Furthermore, it is good to use in an area where there is an issue of moisture buildup because it can resist water drops and mold growth.
Why would you use pressure treated plywood for the subfloor?
Pressure treated plywood offers many benefits over non-treated ones, making it suitable for subflooring. In addition, it can provide a durable platform to put tiles, carpets, or other materials.
There will be no decaying for a long time because the preservative chemicals make it stiffer and stronger to resist the attack of pests.
The lifespan of this material depends ultimately on the frequency of rain, pH of the soil, and other related conditions.
The average time for treated lumber to begin rotting is almost 30 to 35 years.
In contrast, non-treated lumber can last only a few weeks when you use it for exterior purposes and 3 to 5 years when you use it for building a subfloor inside a home.
You do not have to maintain the treated lumber regularly like the non-treated one because it has a good resistance against dust and moisture.
The UV rays can affect the quality due to constant exposure, but there is no need to take so much care as the rays cannot reach it when you add it.
Furthermore, its resistance properties against water make it easy to keep it in a moist environment like in a bathroom.
Resistant to decay
The treated wood can get damaged but does not decay earlier than its estimated lifespan.
This is because it contains environment-friendly chemicals that avoid the degradation process by protecting it against rotting and termites attack.
You can seal the perforations and cuts to add an extra layer of protection over its surface. It keeps changing the color from green to yellow and gray, but it does not affect its properties.
You can apply a waterproof sealer over the pressure-treated wood when it comes out of the tank for the drying process to avoid the negative impact of heat rays on it.
Resistant to flames
The wood can easily catch fire and start to burn when it comes in direct contact with flames. So, it is better to use fire-resistant material that cannot react to fire and protects the house.
The chemicals used for treating plywood make it resistant to fire up to a great extent, or it becomes fire retardant. As a result, it provides permanent protection against flames and does not get burnt.
The solution enters deep inside the lumber and changes its properties. Accordingly, it can slow down the fire spread by releasing carbon dioxide and water that insulates the material.
Protection from insects
Some insects like ants and termites feed on the windows and furniture, particularly on the wood material, and destroy its structure.
In addition, the insects make it hollow from the inside and decrease its strength.
Therefore, it is essential to use this for construction because it provides better resistance against insects and makes it last longer.
The chemicals reach inside the tiny pores, fill up the space, and prevent carpenter ants from obtaining their food.
Availability of multiple sizes
It is available in different sizes and shapes, making it easy to choose the exact one according to the size of the room where you want to place it.
You can get a 2 to 4 inches long and 6 to 8 inches wide sheet. Moreover, it is available in grades like AC, CDX, BC, and CD.
In addition, the thickness of a plywood sheet is 1/4 to 3/4 inches. So, you can easily select the correct size of the sheet after measuring the size of the room and the thickness of the subfloor that you want.
Easy to maneuver
You do not have to put a lot of effort into maneuvering its sheet because it is feasible to cut it in desired shapes. Instead, you can use a handsaw and some fasteners or nails to fix it on the ground.
Moreover, the routers and drillers help create different shapes and make holes deep in the lumber.
Due to better stiffness, it does not shed the excess fiber when you drill a hole in any region.
So, you can change the sheet size and shape by cutting with a handsaw and place on the ground.
Resistant to moisture
You cannot consider this plywood a waterproof material because it cannot stop water from reaching deep inside the lumber.
However, the chemical can prevent water from damaging wood quality and avoid problems like swelling.
In addition, they can control mold growth on the wood’s surface and prevent fungal growth.
You can also use some sealers to prevent the entry of water inside the wood material that can lead to decay after a long time.
Some sealing liquids and paints are available in the stores to prevent water absorption in the lumber.
How to use pressure treated wood for subfloor?
You can start the subflooring process by measuring the exact dimensions of a room. The area of the rooms helps in getting an understanding of the approximate number of sleepers.
Moreover, you can draw lines on the ground at a distance of 10 to 12 inches to get an idea of sleeper quantity.
Cut a few inches of the doors so that they can easily open and close; otherwise, remove the doors until you complete the work.
Check the high areas on the ground and make them equal using a concrete grinder. In the same way, fix the ground dips by filling them with cement mixture and letting them dry.
Clean the surface and remove the dirt and debris before placing treated lumber sheets.
It depends on your choice to add a polyurethane sheet as a base on the floor at a distance of 6 inches and 2 to 3 inches on the wall.
Place ¼ inches of treated lumber at a distance of 10 to 12 inches starting from one side of the wall. Screw them inside the concrete slab for firm fixation.
After that, add insulation sheets or foaming material between the sleepers and place these sheets over them.
Finally, fix the sheets on the sleepers by screwing using flooring screws and cleaning the surface.
What are the disadvantages of using pressure treated plywood on the subfloor?
The plywood treated with chemicals or preservatives is good to use indoors and outdoors, but be careful and avoid using them in the kitchen.
You can observe a shrinkage or warping in the lumber when it goes through a drying process.
In addition, there will be a reduction in its width that can lead to the formation of cracks on the surface.
Furthermore, treated lumber with 1x8x12 inches can cost you around $15.28 to $18.53, which is expensive compared to a non-treated one.
Additionally, the chemicals inside the wood restrict you from using it for kitchen subflooring and countertops.
You can touch the countertop surface, and sawdust can get mixed in your food and affect your health.
What should be the thickness of the pressure treated plywood subfloor?
The thickness of a plywood subfloor depends on the choice of height you want to provide, underlayment options, and their insulating capacity.
It is better to place the sheets of wood on a joist structure that is almost 10 to 12 inches high from the ground.
Ideally, its thickness should be ½ to ¾ inches or a minimum of 5/8 inches.
However, it is not essential to stick with this thickness, and you can maneuver it according to the mentioned factors.
You can add a thin subfloor when the underlayment has better insulation capacity.
In the same way, add a thick sheet when the insulation capacity of the padding material is lower.