Chimney Leak Puzzle

[Jim Katen]

So, remember all that rain that O'Handley was bitching about before Thanksgiving?

Today I looked at a house that was recovering from flooding that occurred during that storm and some things just don't add up for me.

1965 split level with a basement.

As best as anyone can tell, the basement has never had significant water entry in the past.

During this storm, they got about 1" of water across the entire lower basement floor.

The owner said that it seemed to her that the water was coming out from the chimney.

An insurance adjuster and a very good roofer examined the house and agreed with her. They say that the metal caps on the chimney flues are leaking and that's the source of the water.

The roofer was there during the storm and he put a tarp over just the top of the chimney and the water entry stopped.

I'm skeptical. Please look at the attached pictures and tell me if you think that enough water could enter this chimney to flood an entire basement floor to a depth of 1".

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[randynavarro]

No way. Not in a million years say I.

Perhaps the water came up through the slab near the bottom of the chimney?

But that doesn't explain the timing of the blue tarp placement and the water stopping. But to that I say those two events were merely a coincidence.

[hausdok]

That's a flaky diagnosis. We see spark arrestor caps like those maybe 5% of the homes we do here. If enough water flowing down chimneys to flood homes was possible, we'd know about it here. I suspect that they're downspouts are emptying into receivers that wrap around the base of that chimney and there is a corner joint separated below grade right next to the chimneystack. Every time it rains, lots of rainwater gets collected by the gutter, gets sent into the receiver and then leaks out through that hole and perks up in the basement. The house is old enough that you can bet that they probably didn't sleeve the footing drains against fines and they're probably not taking water the way that they used to; so water leaking out of the roof drainage system isn't being collected.

I don't have a crystal ball, I've just seen it time and again (last week most recently) and it was the first thing that popped into my head when you described what was there.

ONE TEAM - ONE FIGHT!!!

Mike

[Jim Katen]

The chimney is smack dab in the middle of the house. The downspouts are way out at the corners of the house.

It might be the rain drain system, but if so, the cause would be indirect.

[Marc]

Consider a small basement of 1,200 SF. 1" of depth comes out to 100 CF of water. That's about 800 gallons. For a 24 hr constant rainfall, it comes out to 1/2 gallon per minute. Through a chimney cap? I don't think so.

Marc

[Ben H]

Consider a small basement of 1,200 SF. 1" of depth comes out to 100 CF of water. That's about 800 gallons. For a 24 hr constant rainfall, it comes out to 1/2 gallon per minute. Through a chimney cap? I don't think so.

Marc

This.

[Les]

I like the idea the tarp placement and leak stopping is coincidental.

Entry down chimney is not likely.

[John Kogel]

I see a few guys have walked on that tin roof. I wonder if the head flashing is leaking, but that would show up on the outside of the chimney.

It is normal for the tarp to go on after the big squall has already hit and the damage is done.

I'll bet the water was peculating up thru the basement drain. That thingy under the carpet there. []

[Les]

Damn! if you look really close at the first photo you can see a guy with a garden hose along the edge of the woods!

[Jim Katen]

Consider a small basement of 1,200 SF. 1" of depth comes out to 100 CF of water. That's about 800 gallons. For a 24 hr constant rainfall, it comes out to 1/2 gallon per minute. Through a chimney cap? I don't think so.

Marc

Yes, I already did the math. With no cover on either flue, the greatest volume of water that could possibly have entered the chimney would have been about 1/2 gallon that day. I've told the owner that not only is it unlikely that the water came through the chimney, it's *impossible.*

BTW, I suspect that it was the insurance guy who stepped in the middle of the steel tiles.

[Tom Raymond]

BTW, I suspect that it was the insurance guy who stepped in the middle of the steel tiles.

That's a shame, adjuster stupidity is always excluded from home owner's policies.