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,

Lisbon Wikipedia, the free encyclopedia Lisbon is the capital and the largest city of Portugal, with a population of 552,700 within its administrative limits in an area of 100.05 km². Its urban area. Residential Homes Castle Rock Realty City Homes & Condos For Sale Through Castle

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