new chimney cap unseals the liner at the top

[newatthis]

OK, I'll do my best to explain. We are getting new chimney caps because of longstanding leak problems, and we told the roofers that we wanted some serious protection from the elements. The caps that are now being installed have stainless steel cylinders that go on the outside of the corrugated liner. In other words, the corrugated liner is the male portion going up into the new exterior stainless sleeve (female portion), all of which will be under the roof of a chimney cap. In this picture here I can feel the cut edge of the liner:



The outside of the stainless steel cylinder will be soldered to the stainless steel "floor" of the cap. Here is the outside, shown unsoldered at this point:




Before this work was done, the stove store installers had put on a small cap right on top of the liner that was siliconed to a flat metal cover to seal off the interior of the chimney (exterior to the liner) from the outside. Which in itself was a drastic improvement from the constant cold air flow we used to have coming into our fireplace.

How important is this seal? Is it supposed to be reasonably airtight? The roofers who are doing this are not wood stove types. On the other hand, a melted metal joint will probably be more sealed than the previous silicone seal. I was planning to get a Sooteater and clean the flue myself, and worry a little that I might break the soldered seal as I bumble my way through my first few cleanings. One liner I will clean only from the inside, but the other I think I will have to get on the outside and work down.

 

[Nick Mystic]

The only soldering that I've done is some stained glass work and soldering wires to make connections. That gap looks pretty big to close up for the type of soldering I've done , so I'm assuming the soldering the roofer does must be able to deal with a gap that large. At any rate, as to using a sooteater for cleaning your flex liner I wouldn't worry about it causing damage to the seal. I have a sooteater that I use for top down cleaning and it doesn't seem to cause a lot of vibration to the top of my stack that I can tell. The spinning head isn't likely to cause any problems, but the rods could cause more vibration if you don't pay attention and keep the rods from contacting the top of the pipe as you work. Even that probably won't cause damage, rather I'm just saying if there was going to be a problem it would more likely come from a rod banging against the liner instead of the spinning head. Post a photo of the finished cap so we can see how it came out. Good Luck.

 

[Heatsource]

alot of work to go thru when they make factory top plates for this application...
something like this:
http://www.efireplacestore.com/cpf-34251.html

 

[bholler]

Yes just order a top plate then caulk it down and rivet it fast problem fixed