First time around we came home from a vacation to Costa Rica over New Year's to find our roof had leaked and left around a third of our master bedroom ceiling. We thought the cause of the leak had been addressed by replacing a small portion of the roof where we had found a ridge in the shingles (see Roof Patch 1 & 2). That ridge was thought to have allowed water to just slightly pool and then enter the roof line to the ceiling via some bad adhesive that left a nail hole accessible to the water. #1, I recommend at least a once a year self-roof inspection. Look for shingles who's adhesive has gone bad, they will be loose. Look for sagging in the roof caused by bad/faulty plywood. And anything else that looks bad. Since I hadn't noticed any issues, this became a problem (obviously). #2 make sure to clean your gutters. This caused an ice issue for my neighbor. As we thought the small roof fix was the solution, we had our ceiling fixed and I painted it. As much as painting can be fun, I'd rather not do it for no reason. So that was a great disappointment for me when he roof leaked the second time and ruined a new spot of the ceiling. This time we examined the roof and determined, as we probably should have the first time, was in need of replacement. What is the primary reason? The pitch of the roof (see Roof Pitches). It is around 3 degrees, which classifies it as a very flat roof and is not well-suited for shingles. So now we're going to have to increase the pitch to get a steeper angle. We'll do this by raising the point of articulation of that portion of roof with the main roof (the troubled flat spot is for the addition that was put on this sixty-plus year old house around three decades ago). This will be at least a three day project. BUT the current 5 inches of snow on the roof/ground makes things more interesting.Tip 3, it helps to have a neighbor who is a really great guy, and a skilled contractor. He did the fix on the first issue, for an amazing price. And he'll be doing the roof pitch fix this time too. The pictures Shingle Dip and Shingle Ridge give you an idea of what was causing some of the problems where water was pooling and doing nasty things to our house.