Expert: Brad Zacharia - 11/5/2009

Question
I have a 19 year old house that has a small offset on the rear, covered with a gable sort of like a dormer roof, approx. 14 feet wide at the eave. The house roof is 84 feet long.  The small offset roof is about in the middle.  A few years back, I enclosed two thirds of a forty foot deck and added a roof over the whole deck.  The new roof is a low slope roof, not flat, but not much slope.  I have a leak when the rain blows mainly, I thought it was where the old offset roof eaves entered the new low slope roof area.  I have sealed and sealed this area, over sealed it and still I have the leak at times.  I know it is hard without seeing it, but, am I more likely to have a problem where the offset roof joins the new low slope roof or is it likely the water is being  blown up and under the shingles causing the leaks?  Would it be feasible or advisable to add a shed roof over the deck roof spanning from the lower edge to the peak of the main house roof to increase the slope and do away with the small offset roof and where it intersects the new low slope roof entirely?  This would also allow for more insulation over the new room and better ventilation.  Presently the ceiling consists of  two by eight rafters, drywall on the bottom and chip board for decking with plastic ventilation channels and six inches of fiberglass insulation.  Your thoughts?  Thanks in advance.  

Answer
You said you have a low slope roof. Then you mentioned shingles. The two do not go together. You cannot put shingles on low slopes or they will leak. If that's your leak you have the wrong kind of roof and there is nothing you can do but start over with the right kind of roof.

Brad