Roof sheathing materials are part of the overall structure of all roofs, no matter what type of shingle or rubber is used.
While roof sheathing creates the foundational structure of the roof, it is not enough to protect the home.
In fact, the roof sheathing also requires protection from further roofing materials. If it were to get wet or be exposed to moisture, it can rot, bringing the whole roof down with it and potentially damaging other parts of the home in the process.
What Is Sheathing on a Roof?
Roof sheathing is a term that applies to the large wooden boards that are nailed to the trusses, or support beams, of the roof to provide the first layer of the roof’s structure.
In housebuilding, it can look as if the house has a roof after the sheathing has been installed to the outside viewer, but in reality, sheathing is just the foundation of the roof and would not last long without proper roofing materials installed on it.
What Is Used for Roof Sheathing?
Traditionally, plywood has been the sheathing material of choice for roofs. It is heavy and solid, but its weight can make it difficult to maneuver, especially in the large sheets that are necessary to reach from truss to truss.
Because plywood can be unwieldy, many roofers prefer to use oriented strand board (OSB). These must also be a minimum of four feet long, but they are much lighter and therefore easier to use.
However, the nail head pull-through resistance is far higher for plywood than it is for OSB. It is still equally common to see plywood roof sheathing as it is to see OSB sheathing.
What Is the Best Thickness for Roof Sheathing?
Roof sheathing thickness should be just under ½-inch thick, or 7/16th-inch thick, in order for the roof to be up to code, which means that roof sheathing cannot be any thinner.
Most roofers will not choose a sheathing option that is thicker than that because plywood is already heavy and difficult enough to deal with at 7/16th of an inch thick.
However, there may be some cases in which it would be prudent to opt for thicker roof sheathing. For example, this may be appropriate if the chosen roof tiles are exceptionally heavy and require more support, if the roof will be exposed to intense weather, or if it must bear the burden of large amounts of snow.
Do I Need to Replace My Roof Sheathing When Repairing or Replacing My Roof?
It depends on the original installation, any damage that has occurred since the last roof was installed, and your preference.
Contact Four Seasons Roofing today to learn more about your options in roof repair and replacement and to set up a free consultation.