Some people prefer OSB because it doesn't require the harvesting of large trees. Instead, OSB can be made from small trees grown specifically for this purpose, or the waste product from milling lumber.
There are several types of OSB:
Standard OSB: Used for roofs, walls, and flooring. It has no special features, but you can find it in many versatile sizes.
Zip OSB: This type of OSB is made specifically for the outer sheathing of walls and roofs. Zip OSB has a waterproof, house wrap-like barrier pre-installed, allowing you to speed up your project.
Subflooring OSB: Subflooring OSB is smooth and strong, and many types will have a tongue and groove at the edges, allowing for easy connections.
HOW DO I USE OSB?
Here are some things to keep in mind when building with OSB:
OSB AND MOISTURE
OSB resists water initially, because the resin and glue holding it together will repel moisture...to a point. Once it becomes saturated, it's very difficult to dry out. OSB tends to bubble and swell like a sponge, separating the layers and rendering itself unusable.
Unfortunately, once your OSB has expanded, it doesn't bounce back to its normal size when dry.
OSB RIGIDITY
OSB tends to be more flexible than regular plywood. However, this doesn't mean that OSB is inherently weaker; it just means it can be a bit bouncy.
For instance, if you're using OSB as subflooring, you want to ensure that your floor joists aren't too far apart; otherwise, you may end up with some bending. That can be an issue if you're planning to install a tile floor above the OSB subfloor, because the grout may crack when the floor flexes.
Using a thicker sheet of OSB may remedy this issue. Also, consider using a higher-grade subflooring OSB for the job.
OSB AND NAILS
Oriented strand board is not known to hold onto nails as well as plywood. For this reason, some roofers prefer to use regular plywood, as they feel the shingles are more secure.
However, you'll have to do your own testing on this one. Different nails and different types of OSB will hold nails differently. When in doubt, use screws!
