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What Causes a Flat Roof to Leak?

  • 03/01/17

Many campus buildings feature flat roofing. Because there is no pitch, these systems rely heavily on a combination of product quality, membranes and initial installation. Some reasons your flat roofs may develop leaks include:

Clogged Drainage
A flat roof relies on a drainage system to remove rain water. If the drainage system is clogged, water will pond on your roof. Ponding water eventually leads to excess strain on the roof, and inevitably the water will start to seep inside.

Damage to the Perimeter Flashing
Flashing is installed on the edges of the rooftop as well as the interior parapets to protect the roof’s membrane. Moisture and water can seep underneath this flashing and into the building if it is not installed correctly, or becomes damaged.

Open Penetrations
Penetrations are common on rooftops, including as drains and pipes. When these are not installed properly, they leave a roof prone to leaks. They should be kept watertight with flashing, wraps, rain collars and pitch pans.

Damage to the Membrane
When a roof’s membrane becomes damaged, it allows water to enter through the opening. Membranes can become damaged for a variety of reasons. Sometimes it is just a matter of age.

The Age of Your Roof
Flat roofing in areas that experience hot summers or harsh winters will eventually start to fail due to age. Most systems deteriorate at about 15 to 20 years post-installation.

This article originally appeared in the issue of .

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