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,

Nystrom Contracting Corporation Roofing Siding Window. Nystrom Roofing & Construction Twin Cities Residential and Commercial Roofing and Construction. Servicing the greater Twin Cities metropolitan area withyears of. – Manufacturer of Quality Building Products. Since 1904, has supplied excellence in its quality exterior and interior building products.

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