Not enough structural support for the load.
Sagging roof support.
In cold winter climates snow is the most common cause of excess weight on the roof.
Poor quality roofing material and faulty installation can cause a roof to.
The cause of a sagging roof is straightforward in theory.
Less common causes of a sagging roof.
Sagging rafters can lead to serious problems with the entire roofing system.
Use your string line to determine how much the roof need to go up.
Solutions can range from simple to downright ugly for your wallet and unless you re comfortable with span tables advanced carpentry and working at heights fixing a sagging roof is almost always time to call a pro.
Non foundational reasons for a sagging roof.
Likewise a flood resulting from a broken water line or natural occurrences can compromise your roof eventually.
Every roof is designed to support a specific maximum weight and anything above this especially for long periods can cause the roof to sag.
Fixing a sagging roof by bolstering the beams.
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.
This is called undercutting.
Bolstering the beams of your roof is another solution to repairing a sagging roof however it is often something that requires assistance from another able bodied person since beams can be extremely heavy.