In many projects that have a sloped roof and an overhang, the underside is often overlooked. Unfortunately, this surface is very visible and a bad finish is not seen until the project is near completion. Here are two examples of how the soffits look with this decking. These are from the Oakdale Walgreens project that had its grand opening in October 2010 which I posted previously. As you can see, it is a great improvement over exposed roof sheathing, which today is seldom plywood, but is typically Oriented Strand Board, known simply as OSB.
For my projects, I have found that T&G decking, with a “V” groove, often serves as a very attractive material. It can be painted or stained, depending on the building color. I am working on a new project and I have just completed this detail. It shows how it is applied. Please note that the rafter needs to be thinned down at the junction where the roof sheathing changes to the decking. I have seen this done by a skillful carpenter with a pencil, a tri-square and a circular power handsaw.
It is important to always use 2x6 and never 1x6 material. An actual dimension of a 1x6 is only 3/4” x 3 1/2”. 3/4” is not thick enough for the roofing fasteners to keep from popping through. A 2x6 has a 1 1/2” actual thickness, which is adequate for most roofing nails.
