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,

When to cover over or pull off shingles Remodeling. Tearing off the old shingles can add anywhere from a few hours to a day to a roofing job. "You could be spending $750 or $800 in dump fees," contractor Jim Lydon. Roofing Contractors in Tacoma, Washington

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