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,

La Salle borough, Montreal, Quebec, Canada. La Salle, former city, Montréal region, southern Quebec province, Canada, on the south shore of Île de Montréal Montreal Island, at the head of the Lachine. CATHOLIC ENCYCLOPEDIA St. Baptist de la Salle St. Baptist de la Salle.

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