When the outer studs, rafters, and joists of a building is covered with a layer of boards or fiber materials or with wood so as to strengthen the structure and to make a base for weatherproofing cladding, it is termed as roof sheathing. Roof sheathing increases the severity of the roof frame. It’s much similar to wall sheathing including the materials too. However the only difference is the thickness of the materials which are used for sheathing. One question do come in mind: what size sheathing do you need for roofing?

Roof sheathing installation – how to install roof sheeting

Making sure your roof's trusses and sheathing is in good condition is key to having a properly installed roof.
Making sure your roof’s trusses and sheathing is in good condition is key to having a properly installed roof.

Normally everybody thinks that roof sheathing is just flat panels on which shingles are attached. In fact it’s a lot more than that. Roof sheathing helps make proper space between the trusses or rafters and to provide the strength to the roof. Roof sheathing has to make according to the structure and should be properly spaced so as to allow for expansion and contraction that happens due to weather change. Before roof sheathing there are some points which has to be known such as what size sheathing for roof will be required? And which is the best roof sheathing for the building. Plywood and OSB roof sheathing are said to be as the best materials for the roof sheathing.

In order to install roof sheathing following steps should be taken:

  1. Find out the exact length of the each rafter by measuring from the peak of the roof to the bottom of the roof along each rafter. Then measure the distance from the peak to the tip of the rafter on the first and the last rafter and make a pencil mark. Now snap a chalk line between the two pencil marks.
  2. Now cut each rafter tail on the chalk line. Make sure that every rafter is of same length.
    Place the first piece of the roof sheathing on the bottom of the rafter tail. Align long edge of the sheathing properly with respect to rafter tails and the opposite edge of the roof. Now nail the sheathing with nailing after every 6 inches along each rafter.
  3. Now place the second rafter align it with the end of the rafter tails. Make sure that there is the gap of 1/8 inches between the two rafters. This is done in order to leave place for seasonal expansion. Repeat this process for the entire first row.
  4. Now place the piece of sheathing over the first one in order to start the second row. Align it with respect to the bottom sheathing. Now raise it 1/8 inches and fix it using farming nails. Now complete the second row and let the process go on until you reach the last row where roof sheathing overhangs are present.
  5. Snap a chalk line along the overhanging sheets along each side of the roof aligned with the edge of the rafter. And cut the extra sheet and nail it. This will fix the last row of the sheathing.
    Now follow the same process for the other side of the roof.

Roof sheathing materials

There are different types of materials which are used for roof sheathing such as:

Some fiber roof sheathings are also used.


We have covered about the roof sheathing and also about the installation process of the roof sheathing. Also in this article you can get the details about the different roof sheathing materials which are very common. Now to choose which one will best for you is up to your selection.


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