How to Find Where Your Flat Roof Is Leaking Without Having to Remove Everything

Place a ladder next to the roof in an area where you can see most of it and climb up. Look closely at the roofing material, whether rolled, shingles or tiles. Identify any visibly missing or torn shingles, broken tiles or holes in the rolled roofing. If any damage is visible, it is most likely the cause of the roof leak.

Walk carefully over the roof and look for standing pools of water or round circles of dirt, which indicate the water pools have evaporated. Kneel down and examine these areas more closely for small holes or tears, which may be the source of the leak.

Look at the ceiling inside the home and identify any dark brown or yellow stains, which indicate water stains. Examine the stain to see if it spreads from a ceiling edge or if there are smaller stains above it, which indicates that the leak is coming from flashing or possibly a chimney rather than the roof above the stain.

Climb up into the attic or crawl space and look for stains that are directly above the stains on the underlying ceiling. If no stains are visible, look at other areas of the flat roof, since the water may run down a vertical rafter before it actually penetrates through to the ceiling.

Ask another person to go outside the home and turn on a garden hose. Have him direct the flow of water at the roof in the general location of the water staining that appears inside. Examine the underside of the roof carefully from the attic or crawl space, using a flashlight if needed, to watch for water drips or leaks. Leaks may take five or six minutes to appear, depending on the pressure of the water.