Metro Detroit’s Masonry Q&A Hub

Why does my chimney only leak during heavy rain but seems fine the rest of the time?

Answer

That’s usually how it starts. We see this a lot in homes around Royal Oak. Heavy rain finds the weak spots—small openings in the mortar or around the flashing that you won’t notice otherwise. It might seem minor now, but it doesn’t stay that way. Water keeps getting in, spreads, and before long you’ve got damage inside too. Most homeowners don’t realize how fast that escalation happens until it’s already affecting drywall or ceilings. Better to deal with it now while it’s still a smaller fix.

I was cleaning out my gutters & pressed my hand against my chimney to balance myself & noticed some of the bricks on my chimney moved a little. Should I be worried about the chimney actually falling over?

Answer

If bricks are moving, that’s a sign the chimney is starting to lose its structure, so it’s something to take seriously. That movement means the mortar has already failed in those areas. From there, it can spread, more bricks loosen, cracks form, and in worse cases the upper portion of the chimney can start leaning or become unstable. The fix is to rebuild the from just below where the damaged begins & the rest of the way up before it turns into a safety issue. Gravity is not your friend in this situation.