You may consider some wood shingle roof systems to be friendly to passer-byes. As you pass by and look up it almost appears that the shingle roof is beginning to wave at you. Even though wood shingles are one of the most impressive roof systems to install on your home or business, they are no friendlier than the average asphalt or slate roof. What you are seeing as you pass by is the curling of the wood shingles and not the wave of a friendly shingle.
Wood shingles are a natural wood product. As with any wood product, they do soak up moisture through the surface of the wood shingle. Through blow back and other factors, moisture accumulates not only on the top of the wood shingles but also on the underside of the shingles as well. In situations where the wood shingle roof system is not properly ventilated, the wood shingles are not able to properly dry as a result of air flow below the wood shingles.
As the wood shingles dry out on the exposed surfaces on top of the shingles, the underside of the shingle remains wet. This creates a dynamic where the surface of the wood shingles that is exposed to the external environment dries out and contracts while the surfaces of the wood shingles that are concealed do not dry out. This creates an effect where the exposed wood contracts while the concealed wood remains swollen with moisture. As this takes place the top of the wood shingle contracts while the bottom remains wet and swollen creating the curling effect.
Wood shingles are one of the most impressive types of roof systems to install and have on your home or business. However, they must be properly installed with required ventilation in order to ensure that the roof does not prematurely curl and fail. Once a wood shingle curls, it must be taken out and replaced.
Photo © Jurin Roofing Services, Inc. Curling wood shingles.