10. LOOKING FOR LEAKS ON FLAT ROOFS, ROOFS WITH A LOW SLOPE AND STEEP ROOFS
The causes of roof leaks are numerous and can occur because of inferior installation of the roof system, items dropped on the roof causing mechanical damage, failure of roofing material, problems with the HVAC, plugged up roof drains and various other situations. Leaks are more difficult to find when the source is a few feet away from the inside area showing water damage.
For instance, if water enters a hole in your asphalt shingles, it runs along the underlayment to another hole that could be several feet away. The water then runs on the decking top to a seam or a hole in the decking. Dropping down into the attic, it runs along the ceiling top to a seam or a hole in the plaster or drywall. When you have several layers of roofing on your building or a vapor retarder at the ceiling level, the distance that the water travels before you see it inside can be even greater. Locating a leak is sometimes more difficult than you think it should be. The following guidelines can help you. When the guidelines use the words “leak area,” they are referring to an area located within 10 feet of the leak.