Building a foundation for longevity.

Many new homes have a stable, sufficiently thick decking material. This is usually in the form of 19/32" OSB. We seldom need to do repairs on this material if we are doing a new roof. Plywood is much more likely to move and work the nails loose, especially with smooth shank nails. Some of the older homes have planking, most having less than the required amount of ventilation, which means the deck is somewhat deteriorated. Planks are also typically gapped more than the warranty and also code requirements allow. It is very high-risk weather wise, and very labor intensive, and therefore costly to remove all the existing decking and install an entirely new decking. It is far more economical to remove all the shingles and underlayment and install a layer 1/2" OSB to the rafters using 3" ring shank Galvanized nails. This makes a very sturdy deck since it is still very supported in a majority of areas with the old decking.