What Happens When Water Gets Trapped Under a Flat Roofing Membrane?

A flat roof is designed to protect your building from rain, snow, and changing weather conditions. However, when water becomes trapped underneath the roofing membrane, it can create serious issues if left unaddressed. Homeowners and building owners may notice signs such as bubbling, blistering, soft areas, or water leaks appearing inside the building.

In many cases, trapped water under a flat roofing membrane is caused by masonry-related issues. Deteriorated brickwork, cracked mortar joints, damaged parapet walls, or failing masonry details can allow water to enter areas where the roofing membrane connects with the building structure. Over time, this moisture can travel beneath the membrane and become trapped between the roofing layers. Other contributing factors may include damaged flashing, open seams, aging roofing materials, poor drainage, or previous repairs that were not properly sealed.

When moisture remains trapped beneath the membrane, it can weaken the overall roofing system by affecting the insulation, decking, and other underlying components. During temperature changes, the trapped water can expand and contract, causing bubbles or blisters in the membrane. If the issue continues, it may eventually lead to roof leaks, interior water damage, and more extensive repairs.

At Anchor Point Roofing, we specialize in flat roof repair and have extensive experience addressing issues caused by trapped water beneath roofing membranes throughout Chicago. Our repair process begins by carefully cutting the affected area of the roofing membrane to access and remove the trapped moisture. Once the water has been drained and the area has properly dried, we install a new roofing patch over the affected section to restore the integrity of the roof system.

For smooth modified bitumen roofing systems, we apply an aluminum coating over the repaired area to provide an additional protective layer and help improve the durability and weather resistance of the repair. This helps protect the repaired section from future exposure to the elements.

If you suspect water is trapped under your flat roof membrane, it is important to address the issue before it causes further damage. Whether the problem is related to masonry issues, roof membrane failure, or other causes, Anchor Point Roofing provides reliable roof repair solutions for homeowners and building owners throughout Chicago. Contact Anchor Point Roofing today for a professional roof inspection and expert repair services.

Location: Chicago, IL