Sheathing 101: Understanding the Purpose and Types of Sheathing Materials

Sheathing is a layer of material that is placed over the exterior surface of a wall to provide a smooth, continuous surface for finishing materials such as siding or stucco. Sheathing serves several purposes:

1. Provides a nailing surface for finish materials: Sheathing provides a solid surface for nails or screws to hold the finish materials in place.
2. Protects the framing from moisture: Sheathing acts as a barrier to prevent moisture from entering the wall cavity and damaging the framing lumber.
3. Helps to control air leaks: Sheathing can help to seal gaps and cracks between the framing members, reducing air leakage and improving the overall energy efficiency of the building.
4. Provides a layer of insulation: Some types of sheathing, such as plywood or oriented strand board (OSB), have built-in insulating properties that can help to reduce heat loss in cold climates.

There are several types of sheathing materials available, including:

1. Plywood: A type of engineered wood made from layers of wood veneer that are pressed together to form a strong, flat panel.
2. Oriented strand board (OSB): A type of engineered wood made from strands of wood that are pressed together to form a panel. OSB is less expensive than plywood but may not be as durable.
3. Fiberboard: A type of engineered wood made from fibers that are pressed together to form a panel. Fiberboard is lightweight and easy to work with, but may not be as durable as other types of sheathing.
4. Plastic sheeting: A type of synthetic material that is used as a vapor barrier and can help to prevent moisture from entering the wall cavity.
5. Metal flashing: A type of thin, flexible metal that is used to cover the top of the wall and protect it from water damage.

It's important to note that sheathing should be installed in accordance with local building codes and regulations, and should be properly fastened to the framing members to ensure its stability and effectiveness.