Chimney liner questions

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Shimanok2

Member
Oct 19, 2012
27
New Hampshire
Hi all,

I've decided this year to install a flex liner into my existing masonry chimney, but had a few questions before doing so. I figured this would be the best place to start.

A) Does the Tee-Scout in the kit go through the existing metal wall sleeve, or does that sleeve get removed to allow the tee snout to be installed. Unless the horizontal tee snout section is undersized (<6") I don't see the former happening.

B) If the latter, is a high temperature insulation installed around the horizontal tee section? I would think some cement would be used towards the inside to "firm up" the horizontal section section in preparation for connecting the stove pipe.

C) I don't believe I have enough cross section inside the flue to fit an insulation wrap around the liner. If I wanted to pour Vermiculite/Perlite down, what is typically used below the tee snout to prevent the V/P from falling down to the basement?

I haven't really found any of these questions answered so far, but if they exist in another thread please let me know.

Thanks in advance for all your input!
 
A) the existing pipe must be removed and make sure your tee snout is long enough to extend through the crock and into the room about 1.5" to 2" if it is not long enough you will need to get some stainless pipe to extend it and rivit that fast to the snout.

B) Yes you pack around the snout with insulation and then mortar over that. You will probably not be able to get any cement in the back.

C) If you don't have enough room for wrapped insulation you dont have enough room to use pour in. To meet the requirements for pour in insulation for wood you need 1" of insulation on all sides. This means you probably need to remove the clay liners. As far as keeping it from going down to the basement do you have a cleanout down there? If so you should extend the liner down to that cleanout and seal it down there.. If there is not a cleanout then you can slide some sheet metal in there if there is room. If not you just fill the whole column.
 
I'm wondering if pre-insulated liner would work. What is the ID of the current tile liner? Is it a straight shot down or offset?
 
A) OK, that makes more sense. I see they sell the tee stouts with the longer horizontal section. I'll definitely need that.

B) Is it advisable to pack as much insulation as possible between the pipe and the masonry? And then just cover up the front section with cement? Or is a lot of cement needed to hold the pipe firmly in place? How much clearance between the Horizontal tee snout and masonry is desired?

C) I can't remember the exact dimensions, but I think the inside is ~7.25" x 11". It is a straight shot from the basement to the crown. No bends at all.

I do have a clean-out down in the basement but wasn't planning on running the flex pipe down there. I can run it though if it's a requirement. I see some of the Tee-snouts come with a cap welded on the bottom. I was planning on going with this option.

Thanks again for all your advise
 
C) I can't remember the exact dimensions, but I think the inside is ~7.25" x 11". It is a straight shot from the basement to the crown. No bends at all.
There's room for a pre-insulated liner. I think that's the approach I would take.
 
Who offers a pre-insulated liner package? I've only seen the insulated wraps that get glued on.

Is insulating an absolute necessity? We have good draft now and the chimney is in the center of the house.
 
You can read about when you must insulate, and when it is a good idea, on our website at (broken link removed to http://www.chimneysweeponline.com/ffwrapwhen.htm). The 6" pre-insulated Forever Flex liner we sell is 7-5/16" OD.
The problem with not insulating is that for one it is usually next to impossible to confirm proper clearances of chimneys. And regardless of that unless the liner was tested and ul listed without insulation for use with wood (which I don't know of any that are) you are still required by code to install the insulation to meet the ul listing. And there is the performance gains as well to consider and insulated liner will preform better than a non insulated one in almost every situation.
 
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