Is OSB Good For The Attic Floor? (Explained!)

Oriented Strand Board (OSB) stands out as the best option, even overtaking plywood in handling a structural load.

Renovating your attic floor not only adds value to your home but also offers more space. However, choosing material that you can call a perfect pick for the attic is crucial.

Don’t forget, the attic floor is a major part of the home, providing insulation and ensuring proper ventilation. If you choose the wrong material, chances are that you’ll face wood rot and dampness all over the place.

Placing hefty hardboards is not the right choice to make; you need to keep things on the lighter note in the loft. Due to this, we count Plywood and Oriented Strand Board (OSB) as perfect choices for attic flooring. They are the most popular options to count on when renovating the attic floor.

But if you have to decide between these two economical engineered materials, who would it be: Plywood or OSB?

Well, to answer your question, the best option to pick is the Oriented Strand Board (OSB) over plywood, as it can bear the structural load. Besides, it is well-suited to the attic floor, and it is a lot cheaper than Plywood. However, manufacturers claim that both of the materials work well.

Is OSB Strong Enough For Flooring?

Yes, it has strong, more rigid structural strength, offering better holding power.

Oriented Strand Board (OSB) is often called Chipboard and is made up of large flat flakes of wood, arranged in thin layers as many as 50 layers, which are then adhered together with phenolic resins and pressed into sheets.

OSB tends to be cheaper than other forms of materials contractors use for floor making. OSB is more uniform, as it has no defects and knots that you can find in Plywood.

Is OSB As Strong As Plywood?

Oriented Strand Board (OSB) is much stronger than Plywood in shear. Not just this, but the thickness of OSB is two times greater than Plywood.

Again, the manufacturers said that both of these materials are great to use and work well. However, when it comes to choosing between OSB and Plywood, many builders go for OSB. What gave plywood a bad name? It was a delamination of early plywood sheathings.

Engineered Wood Association is the agency responsible for the approval of the structural panels that we use in building residencies. This association considers both the plywood and OSB as equals in terms of performance. Some of the engineers said that they both share the same yet standardized span ratings.

Upon researching the withdrawal and performance of staples and nails in plywood and OSB, it was found that OSB performed better than Plywood. Also, OSB responds to humidity and exposure to liquid material slowly.

Pros of OSB over Plywood:

  • It is less expensive
  • It is thick and heavy to offer durability
  • It is more environmentally friendly
  • It is available in a larger panel

OSB holds nails better than plywood, and they are easier to drill into. Some builders found OSB easier to deal with or use, as they have pre-oriented gridlines for measuring, marking, fastening, and cutting simplification.

To make high-quality OSB panels, such as moisture-resistant products, OSB manufacturers use advanced technologies. However, the ones made with advancement are higher in cost than standard OSB, but they are worth the money, offering the best durability and performance.

How Thick Should OSB Be For The Attic Floor?

½ inches in 4ft by 8ft panels over 16 inches OC joists.

However, it depends on the spacing between joists.

For around 19.2 center thickness, you can go for 23/32” OSB. But if you are working on joist spacing, which is around 24”, you must go for 7/8” OSB. And if you are working for around 32”on-center joist spacing, be sure to ideally pick 1 1/8” thick OSB.

What Kind Of Wood Should I Use For An Attic Floor?

Besides OSB, you can use ¾-inch plywood. Thinner Plywood is acceptable when the spacing between joists is around 16 inches. Whether you are planning to make your attic a living room or considering dumping extra stuff here, you should always go for Plywood rather than OSB.

Advantages of Plywood

  • It is light in weight
  • It offers durability better than other materials
  • It can cover the largest area
  • It is eco-friendly
  • It is less prone to moist and decay problems
  • It is great for curved surfaces and is pliable

Plywood is a versatile building material used for a variety of purposes, one of which is Attic Flooring. The best part? Plywood helps reduce sound transmission and offers great insulation against high temperatures in the attic.

For attic flooring, plywood is best after OSB, so you can opt for it as well. Don’t think that it’s too expensive, though, since cheaper materials are prone to cracking when exposed to moisture.

Should I Use OSB Or Plywood For The Attic Floor?

As discussed above, both materials have their separate advantages to offer. Both of them work well, according to builders. However, if we compare both materials, experts recommend that you opt for OSB rather than Plywood.

Besides, many engineers said that both materials share the same qualities, such as durability factors and temperature reduction. But OSB is much better than Plywood in terms of cost, weight, and structural strength.

To Sum Up

The choice between Plywood and OSB is pretty obvious: OSB for sure. While OSB is heavier in weight compared to Plywood, it is indeed the best option to pick for your attic flooring. For sure, an attic is a major part of our home, so treat it with care. The best material for attic flooring is OSB, which stands for oriented strand board, made from fine flakes of wood, joined together through glues, and pressed to form a single layer sheet.

Hope this blog helped you understand which material you should go for attic flooring; OSB or Plywood.