Flat Roof Leak Detection in Berkeley

Why Flat Roof Leaks Are Hard to Pin Down

On a pitched roof, gravity gives you a straight line from the leak to the stain. On a flat roof, water can travel fifteen to twenty feet sideways along the decking before it finds a gap and drips into the building below — especially on older corrugated decking, where water can channel along the flutes.

That means the stain on your ceiling tells you where the water landed, not where it got in. Guessing based on the stain alone is how roofs get “repaired” two or three times without the leak actually stopping.

Our Two-Step Triangulation Method

We start inside, measuring the water stain’s position relative to two fixed walls. Then we take those same two measurements up on the roof, which gives us a starting point directly above the interior damage.

That starting point is where the investigation begins, not where it ends. From there we check every transition within range — flashing, parapet caps, skylight curbs, penetrations — since that’s where the large majority of flat roof leaks actually originate.

When We Use a Grid Search

On roofs that have been patched multiple times, or where the triangulation point doesn’t turn up an obvious defect, we switch to a process of elimination: marking out roughly eight-by-eight-foot sections across the suspect area and checking each one in turn until we find it.

Frequently Asked Questions