Flat Roof Leak Only Happening at Night — What’s Going On?
BERKELEY FLAT ROOF BLOG
Flat Roof Leak Only Happening at Night — What’s Going On?
It’s rarely actually about the time of day — it’s usually about temperature and condensation dynamics that happen to peak overnight.
What feels like a “night leak” is often condensation forming as temperatures drop after a warm, humid day — moisture that was in the air or trapped in roofing layers condensing out as things cool down. This is a different mechanism than a rain-driven leak and needs a different diagnosis.
It can also simply be a coincidence of timing — an existing leak that happens to reach a visible drip point after enough time has passed since the rain started, which often lines up with evening or overnight hours purely by chance.
Leak with a strange, inconsistent pattern?