What Causes a Flat Roof to Leak?

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 .

Featured

  • Phoenix School District Breaks Ground on New Prep Academy

    The Creighton Elementary School District near Phoenix, Ariz., recently broke ground on a campus replacement for Biltmore Preparatory Academy, according to a news release. The new space will allow the school to expand its enrollment by 50 percent for K–8 students and accommodate modern, collaborative learning styles.

  • S4L Announces 2026 Education Design Showcase Winners

    Spaces4Learning is thrilled to announce the winners of the 2026 Education Design Showcase! Now in its 27th year, the annual awards program honors innovative solutions in planning, design, architecture, and construction across K–12 and higher education.

  • Arizona District Breaks Ground on Community Training, Learning Center

    The Tolleson Union High School District (TUHSD) in Tolleson, Ariz., recently broke ground on a new Training & Learning Center (TLC) for both district professionals and the community at large, according to a news release. The 90,000-square-foot facility has an estimated completion date of spring 2027.

  • Architectural Power for the Modern Campus Landscape

    For generations, an outdoor classroom only required a textbook and a patch of grass. Today, not only has the laptop replaced the printed pages, the rise of agile learning has turned campuses into study halls with students listening to lectures and researching topics from quads, gardens, and plazas. The challenge for architects and facility managers is to provide connectivity without cluttering the landscape with visual eyesores or creating safety hazards with extension cords.