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,

mullioned definition of mullioned by The Free Dictionary A dull light shone through heavy mullioned windows, and from the high chimneys which rose from the steep, highangled roof there sprang a single black column of smoke. mullion definition of mullion by The Free Dictionary mullion mullioned

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