Are you replacing your current roofing material, and it has been discovered that you need a new roof deck as well? You'll likely need to pick between using plywood or OSB to replace the old roof deck. Here is what you need to know about using either of these materials.
Many roofers use plywood because it is very flexible, having several layers of wood material that are glued together. This also causes the material to be very thin, while also holding a lot of weight. This gives plywood a huge benefit as a roofing material; it is not going to raise the height of your roof, and it will help the roof look more aesthetically pleasing from the ground. Plywood is also impact resistant, so it is going to perform well when you deal with strong winds and hail damage to your roof.
One of the downsides of plywood is that it is not going to be as resistant to insects as other roof deck materials, so you could run into problems down the road in that area. If plywood does get wet from a leak in your roof, the material will swell up until the water has a chance to dry out. This shouldn't cause damage to your roof, but it is a reason to be concerned about the material.
OSB wood is made from wood strands that are formed into thin sheets of wood by using wax and adhesives to cause them to bond together. You'll find that OSB is cheaper than plywood, so it can really help you work within a tight budget if it is necessary. You also shouldn't have trouble finding OSB in the various sizes that you need to make it fit on your roof.
One disadvantage of OSB is that it does not resist water that well. The material is treated for waterproofing during the manufacturing process, but any part of the board that is cut will need to be treated on those exposed ends so that the material doesn't absorb water. OSB is also known for being a noisy material. While this should not be a huge problem for roof deck material, it may cause the rain to be a little bit louder during heavy storms.
If you're not sure which material is going to be best for your home, reach out to a residential roofing contractor to help you choose.