Sealing Wall thimble against corrugated Steel outside wall

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Gotrek

Burning Hunk
Nov 20, 2014
242
Manitoba
What would be the best solution to seal the gaps between the wall and thimble on a corrugated steel wall?

I was planning on cutting a fairly tight fit between the wall and thimble and using High temp caulk there but what about the gaps between the wall and the corrugations? Do I need something there?
 
That is a challenge. One option would be to create a custom sheet metal flashing that gets scribed or traced to match the ribbing, then trimmed to fit.
 
I'd cut a square out of the siding and mount the thimble to the sheathing. Then just slide a right angle bent piece of flashing up under the upper siding and another under the bottom of the thimble and over the exposed top of the siding.
They make foam "closure" strip that you can use in conjunction with the metal to stop air infiltration as well.

Your local building supply (real lumber yard, preferably not a box store) should be able to walk you through it and even order you color matched parts that will work. Should be under $20 in materials and you'll have leftovers.

If you're unsure of the brand take pictures and measurements with you.
 
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Thank you.

I found this picture Lots of options those track or sidewall flashings look like they'll do the trick. I'm not sure I have sheathing on the building exterior. The Steel is affixed directly to the studs (pole barn style) the insulated and sheathed on the inside. I removed the interior Sheeting (that's how I know).

http://www.emsupply.com/pages/images/RoofingFlyers/FlashingLocations.jpg

Could I use the thimble by butting it against the inside of the steel panel and only cut a hole big enough for the class A chimney to pass through on the outside. then just silicon around the chimney and steel corrugated panel? I'd think the steel wall itself is considered a non combustible it's a thicker guage then the thimble.
 
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I'm not a chimney installer, plenty of people here are, but I'm pretty sure the thimble, (both halves) need to be used and mounted to framing. While what you're proposing doesn't sound a lot different than what the thimble does, I'm not sure an insurance company would see it that way. Also, I believe both halves work together to help support the "through the wall" section of pipe, but again, the siding could do that too.
I would pull the metal, box it out, mount the through the wall kit, re-apply siding with flashing. Not saying it's the only way to do it, but as a contractor who doesn't want a "call back" that's how I would tackle it.
Also:
http://www.abcmetalroofing.com/
They're one of the larger suppliers here in New England, not sure about you're neck of the woods.
 
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