What is Roof Sheathing?

A roof is not only just made up of shingles or tiles but is a complex system of several different elements that all work together to protect your home. One critical part of the roofing system is your roof sheathing, so what exactly is roof sheathing? This article will focus on what roof sheathing is, why it is important to the roofing system as a whole and some of the different types of roof sheathing.

What is Roof Sheathing?

Roof sheathing is the material that goes on top of your roofing structure including the trusses and beams, that the roofing system is constructed on. The trusses and beams of the roof give the roof its initial pitch and structure and then the sheathing is applied so the actual underlayment and roof covering can be applied. There are a few different terms for roof sheathing, such as roof decking but sheathing is one of the more popular terms. When you see construction workers transporting large flat pieces of lumber up to the roofing structure they are more than likely constructing the roof sheathing.

What is Roof Sheathing Made Of?

Roof sheathing is almost always composed of wood in the United States but there may be different types of wood used. Oriented strand board (OSB) is one of the most popular materials for roof sheathing. OSB is lightweight, cheap and strong enough to resist bending or breaking should someone be walking on the roof.

Roof sheathing may also be constructed of plywood. Plywood is a bit more expensive than OSB but is usually stronger. Plywood may be used instead of OSB in cases where the roof covering is especially heavy, like in the case of slate, clay or concrete tiles.

How Do I Know What Sheathing I Need?

Sheathing comes in different thicknesses and what type of roof you have will help designate what type of thickness you need. Steeper roofs tend to have thinner sheathing due to not much weight being applied to the roof while flat and low sloop roofs that are likely to gather weight from precipitation or people walking on it.

What type of sheathing you need depends on your roofing material, your home and city and jurisdiction code. A roofing consultant or contractor can help make sure you get the right type of sheathing for your home.