Let me start by explaining that my house is 30 yrs old and the roof has been sagging in various locations for at least 20 yrs. I didn’t know what had caused this problem so I called a local contractor that came out and looked at it. He diagnose the problem as “builder incompetence” saying the builder faced the crowns of the trusses in the wrong direction. He offered to fix my roof by shimming the trusses between the plywood from inside the attic and then re-roofing. I would have went with him but the price seemed bit excessive for the work cited, and he didn’t answer all my questions with very much confidence. My cousin in Tiverton told me he was happy with the roofers he hired 5 yrs ago. He said they offered free roof inspections so I figured what the heck. The owner came out to my house and after looking in the attic said, “this is an easy fix” “you have a broken vent hose from your bathroom vent that is pumping extra moisture into your loft” “you also have too much insulation near the soffits and not enough ventilation overall” He said you have slowly bent the trusses the same way one would bend wood to make a bentwood rocker. He explained steam from the shower temporarily weakens the trusses and the pressure from the weight of the roof causes them to sag before they can dry and become rigid again. The fix required tearing out plywood that received moisture damage and sistering the trusses that were bent and then re-decking those same areas. It also required the removal of some insulation, installing baffles from the soffit vents and installing a ridge vent across the entire roof. I received a price for this work plus a Lifetime Owens Corning Shingle for $2000.00 less than the guy who wanted to just shim my roof and then re-shingle. Exclusive Roofing Inc. completed the job in one day and I couldn’t be more happy with the outcome. When they left my yard it was actually cleaner than when they started. I’m not kidding… I guess if there is a point to my story it is, search for a contractor that has enough knowledge to answer any question you could possible ask them. It is your job to do some homework and ask as many questions as possible. If you are not happy with the answers, move on to the next guy until you are satisfied. With exclusive Roofing Inc. I believe you will be satisfied. I know I am.