Flat Roof Repair

Flat and low-slope roofs require a completely different approach than pitched roofing systems. Rather than shedding water quickly by gravity, they rely on a continuous, seamless membrane and proper drainage to move water to scuppers or interior drains before it can pond and infiltrate. When seams separate, membrane blisters, drains clog, or flashings at parapet walls fail, water can sit and work its way in gradually — often going unnoticed until interior damage has already occurred.

We work with the most common flat roofing membranes found on Corona homes and small commercial buildings: TPO (thermoplastic polyolefin), EPDM rubber, and modified bitumen (torch-down or peel-and-stick). For each material type, repairs must be made using compatible materials and techniques — a patch that works on EPDM will not bond correctly to TPO, for example. Our team identifies the membrane type and applies the correct repair approach, whether that means heat-welding a seam, torch-applying a modified bitumen patch, or applying a compatible membrane adhesive.

We also address the drainage systems that are essential to flat roof performance — clearing blocked scuppers and internal drains, correcting low spots that trap standing water, and re-terminating parapet flashing that has lifted away from the wall. A properly repaired flat roof should drain completely within 48 hours of rainfall with no ponding remaining.