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,

Rogue River Bridge, Gold Beach Oregon History Project enlarge this image. The Lee Patterson Bridge across the Rogue River on Highwayat Gold Beach is depicted above at the time of its completion in 1931; it. Jewels of Highway Oregon s Coastal Bridges The Jewels ofOregon

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