Decay can occur over time due to a number of reasons including leaks in the roof or leaks from guttering or downpipes wet rot or even insect attacks such as termites damaging the ends of the bearings.
Roof ridge sag.
He advised the insured that immediate temporary structural reinforcements should be inserted under the cracked ridge board to relieve the load on the broken ridge board and rafters.
Installing new rafters directly alongside the weak or damaged ones is often enough to correct this problem.
On initial review of the garage roof interior our expert immediately saw the cause of the garage roof bowing.
Water damage although roofs are designed for optimal water drainage flooding or heavy rainstorms over time can cause damage to the structure of the roof.
A ridge that droops in the middle forming that unintentional western design feature likely is due to undersized rafters and or missing or inadequate internal bracing rafter or collar ties.
In a stick frame non truss sloped roof these issues usually cause the roof ridge to sag in the middle giving it a swayback look but can also cause one side of the roof to sag.
A sagging roof can come in one of a few classic forms each with its own cause.
The most common cause of sag at the roof ridge is loss of triangulation due to failure of the bottom leg of the triangle which makes the peak of the roof sag and top of the walls spread outward in the area of failure.