The potential for pooling water is one of the few downfalls of flat roofs. It can lead to leaks, roofing erosion, and other issues, so you need to address it early. Here’s how to eliminate standing water and enjoy a sturdy, reliable flat roof for your commercial building.

A Guide to Pooling Water & Flat Roofs


Flat roofs require a drainage system that will evacuate standing water that collects after a rainstorm. Water won’t flow toward the drain if the roofing membrane’s pitch is too shallow, causing it to pool. Clogged drains can also lead to pooling.

roofingStanding water will start attracting insects and wear down the protective membrane on your roof. Once it's weakened, water can slip through this membrane and erode the roofing. It will eventually leak into the building and cause water damage.


Pay attention to where water is pooling. These low spots need to be resurfaced so they’re flush with the surrounding roofing membrane.

Applying a plaster filler and smoothening the surface can solve the problem. Professionals will need to unclog drains if debris has created blockages, which involves snaking a rotary tool down the pipe to destroy the debris.

You may need to completely resurface and re-pitch the roof if standing water is collecting in multiple large areas. Professionals may also need to extend your drainage system if the average amount of water is too much for a single downspout to handle.


Check your roof after a storm for debris that may clog the drain. You may need to trim back overhanging foliage or apply a leaf guard on the drain and gutter system.

Professionals may recommend monitoring your roof’s pitch in the future. If you notice water isn’t flowing toward drains, you’ll need an inspector to take a closer look at the drainage system.


If you need help managing your flat roof, the roofing professionals at Marshall’s Contracting will assist. They provide a variety of construction and repair services to Jessup, MD, including roof replacements, storm damage repair, and new shingle roof installation. Learn more about the company online, or call (410) 406-7667 to schedule a consultation.