The main factor that may weaken the stability of the roof structure is dampness. On its negative impact it is particularly exposed rafter framing, which deform under impact of water. Therefore is important roof protection against getting in  water into its internal structure.

Typically, investors during the construction of the roof attach great importance both for building materials, as well as careful execution. Unfortunately, later very often they forget about the survey, and any minor defects  commission outsource cheaper and often non-professional roofing companies. This is a big mistake,

Wedge Roofing Marin Roofing & Spray Foam Company Roof and spray foam contractor serving Marin, Sonoma and the San Bay Area since 1976. Roof repairs, replacement and maintenance experts. Petaluma City of Petaluma, State of California. Water Resources and Conservation Sewer Lateral Replacement Program

A very important element that must be considered when the roof is projected, is ventilation, allowing drainage of excess dampness from under the roofing.