Water – Can fiberglass insulation cause leaks

chimneyinsulationleakroofwater

I've recently bought a 100 year old wood frame house from a DiY guy who took decent care of the place. He didn't put any insulation in the attic though and my home inspector said insulation is a great easy home improvement project with very little downside or risk.

So among a few other projects, I started buying a batt of 19 faced insulation every time I go to the store, and then laying it piece by piece. My plan was to then buy 30 r insulation unfaced and lay it on top.

But…

We've had some exceptionally hot weather this summer. Today there's a fierce thunderstorm, and I'm sitting by the chimney and I hear drip… Drip… Crap. I run up to the attic, and I have two significant leaks. One from the chimney flashing, and one from the attic vent. Rest of the attic is bone dry.

I run to the basement and there's a stream of water running from the wall. I used to see lots of condensation on the floor but this is visible moving water. Woah, that's new.

Obviously these need fixed, and obviously my insulation needs to air dry now. But the timing has me suspicious. Did I cause the leak? Did the attic overheat and cause something to shift? Or did the ancient chimney just finally wedge the wood frame enough for water?

Should I pull the insulation out and can the whole project? Or fix the leaks and forge ahead?

Thanks for any help.

Best Answer

Correlation is not causation.

No, the insulation did not make your roof leak around the chimney nor at the vent. Being 100 years old (and odds are great someone did something sketchy during one of those years, though even the best construction/repair jobs don't last forever) did that. Rather than chase chimeras, fix the leaks.