Builders use both structural and non-structural plywood during construction. When it comes to your floor and your home, can you use non-structural plywood?
If you plan on using the non-structural plywood as indoor flooring, you’re in luck. You can use non-structural plywood as indoor flooring without much worry.
However, if you plan on using it as deck flooring, you’ll have to find another material because you shouldn’t expose non-structural plywood to moisture.
Now that we’ve got that out of the way, let’s go through the main differences between structural and non-structural plywood.
Structural vs. Non-Structural Plywood
During construction, almost all of the plywood you see in your home is structural.
That’s not only because it’s much stronger than the non-structural variety, but also because it can withstand exposure to moisture and changing temperatures.
Let’s compare the two types of plywood now.
Structural Plywood
The main difference between structural plywood and non-structural plywood is the type of glue used during production.
In the case of structural plywood, they use what’s called an A-bond glue. You’ll often see structural plywood labeled “exterior” or “exposure rated.”
You can make A-bond glue from phenol-formaldehyde resin, an extremely adhesive substance. It used to be a popular ingredient for constructing circuit boards, but newer adhesives have since taken its place.
A-bond adhesives work so well because of their ability to withstand changes in their environment. It is waterproof and can withstand temperatures as high as 428ºF.
With these attributes, it serves as a solid and durable building material.
Plywood that has B-bond adhesives is also considered structural plywood. B-bond glue uses a melamine resin, which is also water and weatherproof. A-bond is slightly better at keeping moisture out than B-bond, though.
Non-Structural Plywood
Non-structural plywood uses either C or D-bond adhesives during its fabrication. C and D-bond adhesives are not waterproof, which is the another difference between structural and non-structural plywood.
You’ll often see non-structural plywood labeled “indoor.”
Both C and D-bonds use urea-formaldehyde (UF) adhesives. UF adhesives are firm but not moisture-proof. If you were to use non-structural plywood during construction, there’s a chance water could leak through, causing extensive damage.
C and D-bond adhesives also react negatively to changes in temperature. If you used this type of plywood for exterior uses, the glue would break down quickly, and you’d have to pay for costly repairs.
Which is Best for Flooring?
When most people talk about flooring, they mean the flooring inside their home. You can use non-structural plywood as indoor flooring because you should not expose it to changes in temperature that could deform the glue.
As indoor flooring, your plywood will also stay dry. Since you can isolate your plywood from both temperature changes and moisture, you’re safe to use non-structural plywood as flooring in your home.
Advantages and Disadvantages
Now that we know more about each type of plywood, let’s go through the advantages and disadvantages of each.
Advantages of Structural Plywood
Weather and waterproof
Certified for both indoor and outdoor use
Suitable for trusses and other supporting structures
Solid furniture material
Disadvantages of Structural Plywood
More expensive than non-structural plywood
Low-grade veneers
Not good for finishings
Advantages of Non-Structural plywood
Less costly than structural plywood
Certified for indoor use
Suitable for finishing work (including floors)
High and low-grade veneers are available
Paints and stains look great
Disadvantages of Non-Structural plywood
You cannot use it outdoors
Not as strong as structural plywood
You can ruin it if exposing it to the elements or moisture in-house
