Another cause of ridge deflection is impact damage to rafters.
How to fix a sagging shed roof ridge.
How to repair sagging roof.
How to fix sagging roof trusses or rafters.
You ll need a steel l channel to get your rafter or truss back into shape.
If your rafters are still sagging a bit and it is causing your roof to dish out a little in the center of the roof sides add a 2x4 that goes all the way across the rafters in the center of the length of the rafters.
If that s what you re dealing with regarding your home take these steps to ensure your rafter or truss gets fixed properly.
If you have just stepped outside your house and realized that your roof is no longer straight this could signal a problem.
Use your string line to determine how much the roof need to go up.
If you notice that there is a visible dip in your roof chances are you have a problem with one or several rafters and you may soon be facing more issues like water leaks bowed out walls or your roof caving in on you.
The first photo below shows a roof with an area of ridge deflection viewed from the side that is barely noticeable followed by the same area sighted down the ridge line.
A sagging roof can mean any number of things.
Also take into consideration your new roofing material if necessary.
Sagging rafters improperly constructed roof walls not appropriately built etc.
This article series describes explains the directions of forces in roof structures illustrating downwards force horizontal thrust and the causes of rafter sags rafters that disconnect from the ridge or top plate and why a sagging roof pushes the building walls outwards at the wall top.
When the damage occurs on only one side of the roof the ridge will drop and move sideways as shown below.
In many cases you ll need to fix sagging trusses or rafters to repair your roof.