Locating Flat Roof Leaks
Tips on Locating Flat Roof Leaks
Flat roof leak roofs can be a devil to locate. The reason is that water can enter one spot and not really express itself inside until it is far away from the leak. The same thing can happen on sloped roofs, however, you can usually discount all the roof area below the area where you see the leak. Why? Because water doesn't generally flow uphill from the leak location. Flat roofs allow the leak to travel in any direction from the leak point. That is why they are tough to locate.......
Start With a Dry Roof
If you have a flat roof that leaks, get up on it when it is dry and cool. You want to look for trouble spots that generally are the primary source of leaks.
I always start at flashings. Flashings are transitional roofing materials. A flashing connects a roofing membrane to something that is not a roof. For example, If a plumbing stack or chimney pops up through the roof, it will be surrounded by a flashing. Often the flashing materials are metal. Look for cracks. Look to see if the flashing overlaps the roofing material such that downward falling water will be deflected away from the chimney, wall or plumbing pipe.
Check the edge of the roof. Often flashings are used at these points as well. See if they are secure. Look for little cracks, openings, or breaks in seams in these flashings.
Dry Mini Lake Beds
Often water will pond in low spots in a flat roof. You will see evidence of these areas on a flat roof. Look for concentric rings of dirt as the puddles dry out. Look here for tiny holes or splits in the roof.
Seams - A High Priority
Any seam in the roofing material is a natural spot for a leak. Look closely at all seams. Do you see cracks or holes of any type? Is there a place where you can lift a small edge of a seam?
Testing For Leaks
You can test for leaks using a hose. But you have to be patient and you need to work backwards away from gutters or center drains. It can take hours, as you need to let the water run slowly over areas you think are trouble spots. Remember, it can take 10 minutes or more for the water to begin dripping inside. Start near a drain and let the water slowly run. Periodically, adjust the hose so water flows across dry portions of the roof. You will need tremendous patience, especially if all portions of the roof appear tight.