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,

Professional_Roofing s_Home_Page Professional Roofing Installing New Shingle roofs New Commercial Roofs specializing in single ply metal tile builtup stonecoated types of roofs Gerard Carlise Gaf. the community for roofers and people with roofs Roofing Prices Roof Replacement Cost & Roof Shingles Prices An overview of roofing

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