ROOF LEAKS HAPPEN, despite a roofer’s best efforts. For example, due to sun exposure, the daily expansion-and-contraction of our school building’s flat roof will eventually push up its roofing nails. When that happens (if it’s before the routine maintenance work pounds those nails back down again), rainwater can find its way in—around a loosened nail or two.
So it’s not surprising that yellowish water stains will show up on a ceiling occasionally. Unfortunately, although staining is a predictable eventuality, we did not seem to be well prepared for it. Even so, things seemed to have worked out, as this post relates.…


