Your roof is an important component of your house. As a Home Inspector, I'm interested in a roof's design, construction, current condition and maintenance. I love a steep and simple roof- a design that promotes longevity - but roofs come in all sorts of shapes and sizes. So what should we be looking for when evaluating a roof?
The first thing would be the condition of the shingles. If we see curling edges, wide gaps in the tabs, a reduction in the granular coating or missing shingles the roof may be nearing the end of its lifespan. Second, we're looking at how the way valleys were handled-- that's where different angles of the roof meet. Was flashing used or are the valleys woven? Was it done in a professional way or does it look like a DIY project? These areas are very common for leaks and we'd see these in the attic or the ceiling. Next, how are all the things that project through the roof handled? The vents and the chimney require flashing or some other consideration to prevent leaks and I verifying the condition and construction technique in each of those places.
Need a new roof? To save money, some people elect to cover their old roof with new shingles because it saves the cost of tearing off the old shingles. When we see this, we call it out because this practice cuts the life of the new shingle in half...your new roof will last half as long! It's a false economy. So, one of the things we always verify is how many layers of shingles are present. The roof on this mid-century modern in Short Hills, NJ has a low slope and a lot of trees hang over the roof causing deep shade much of the time. The combination of lots of moisture and shade led to growth of moss on the north face. This roof was torn off and new 50-year shingles were installed.
In future posts we'll look at roof cleaning and maintenance.