ANSWERS
Flat Roof Leak Repair: Frequently Asked Questions
Straight answers to the questions Berkeley property owners actually ask about flat roof leaks — cost, DIY vs. pro, causes, and fixes.
How much does it cost to fix a leak in a flat roof?
It depends on the cause and extent of damage — a single flashing repair costs far less than a full membrane replacement. See our full cost guide for the real factors.
What should I do if my flat roof is leaking right now?
Move valuables out from under the leak, contain water safely, and avoid walking on the roof during rain. See our emergency repair page for next steps.
Why does my roof only leak when it rains hard?
Usually a specific, localized defect rather than widespread failure. Read why this happens.
What is the 25% rule for roofing?
A general principle where a large enough repair scope can trigger broader code-compliance requirements. Read our full explanation.
Can a leaking flat roof be repaired, or does it need replacement?
Most localized leaks can be repaired. See our complete guide for when replacement makes more sense.
Do I need a permit to repair a flat roof in Berkeley?
Most significant repairs do, some smaller ones are exempt. Details on our permits page.
What is the best sealant for a flat roof?
It depends on the situation — mastic, silicone, and liquid rubber each suit different conditions. See our sealants guide.
How do I waterproof a leaking roof?
Temporary containment differs from a permanent fix. Read temporary vs. permanent fixes.
How do I find where a flat roof is actually leaking?
Water travels sideways under the membrane before showing up inside. See the method we actually use.
Can I patch a flat roof myself?
Sometimes, for small, clearly identified damage. Read our honest DIY vs. pro guide.
What causes ponding water on a flat roof?
Inadequate slope, clogged drains, or a settled low spot in the deck. See our ponding water page.
How do I choose a flat roof material?
EPDM, TPO, PVC, and modified bitumen all perform differently. See our materials guide.