Roof Ridge Sag

On initial review of the garage roof interior our expert immediately saw the cause of the garage roof bowing.

Roof ridge sag.

Installing new rafters directly alongside the weak or damaged ones is often enough to correct this problem. 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. 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. 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.

When you have undersized rafters or inadequate storm bracing snow or ice resting on your roof may cause it to sag. Some roofs sag because of decay to the inside beams and sheathing. A sagging roof can come in one of a few classic forms each with its own cause. 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.