This Doesn’t Look Right
“If it doesn’t look right, it probably isn’t,” it one of my favorite saying. I started saying that after numerous times of seeing something that didn’t look quite right, and upon further examination I found that it wasn’t. That is what we have in this article.
When I go up on a roof during the course of an evaluation, I sometimes see a sunken area like the one in Figure NR-1.
If you see this condition on a roof, don’t get too close until you have had a chance to examine the structure from below. The broken leg that you avoid may be your own.
From the underside the we can see that the plywood roof deck is severely sagged, soft, and decayed, as shown in Figure NR-2.
If I had stepped on a sunken area like this one, there is little doubt that I would have stepped through the deck, damaged the roof, and very possibly hurt myself.
Examination of the pattern of decay, delamination, and water staining on the underside of the roof deck discloses that there is a roof leak near the ridge. Examination of the roof components on the roof disclose that the leakage is emanating from the interface of the fascia of the upper roof and the shingles of the lower roof, as shown in Figure NR-3.
Further examination may disclose the reason for the leakage at this location. The cause is often lack of flashing or improperly set step flashings that direct roof runoff under the shingles. The multiple layers of sealant indicate that there has been at least one previous attempt to stop leakage at this location.