Over 25 years ago wood shingle roof systems were very common in San Diego. But over time they have been found to be highly flammable and are being replaced at a rapid rate. With new local fire codes, we will no longer find these roofs in existence in the next few years.
When replacing an old Wood Shake Shingle Roof, the first step is to do a roof tear off down to the skip sheathing. Skip sheathing is a roofing surface that consists of 1”x4” or 1”x5” boards that are installed perpendicular to the rafters and provide a couple inches of spacing between each row of boards. It’s common to find skip sheathing under old wood shake roofs because in the past it was believed that the openings between the wood slats would let the roof breath and make the roof last longer. But we now know that wood shake roofs actually last longer when installed on a flat plywood roof surface.
This particular roof not only had wood shake shingles installed but it also had a layer of asphalt shingles installed on top of the existing wood shake shingles. Once both layers had been removed, we installed 4’x8’ OSB sheathing on top of the skip sheathing. OSB stands for “oriented strand board,” which consists of compressed wood strands bonded together by resin. These boards are much stronger and stiffer than traditional plywood boards.
With the proper full sheeting in place, we were able to continue with the rest of the roofing process. This included installing proper underlayment for an asphalt shingle roof, installing Owens Corning asphalt shingle on the entire roof, installing an Owens Corning ridge vent, reinstalling a solar tube, and installing all necessary flashings. The new roof will last for years and years and looks much better than the existing roof.
You can see the entire process on this home in San Diego.