Flex Liner Install Question

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msjones2452

New Member
Feb 23, 2015
74
Denver CO
So, just finished the install on my new Hampton HI400 this weekend and I have a question about something I did when installing the chimney cap. The liner I installed was a heavy wall flex liner from Fireside Chimney Supply w/deluxe terra cotta cap. I kinda got in a rush to finish buttoning things up because I was losing light fast and wanted to get things done before going back to work. I was tired and obviously not thinking at the time (I know, should've just called it and finished at a better time!). When I moved the band clamp holding the wire mesh and cut back the excess liner insulation, I didn't go down far enough. So, when I put the chimney cap on it wouldn't seat on the terra cotta flue. Not thinking, I stood on the cap to get it to sit flush, snugged the holding screws and tightend the strap to the liner. After thinking about it I figured that the reason the cap wouldn't sit flush in the first place was because the band clamp and liner insulation was in the way. The cap is not touching the clamp at all, just pushing down on the insulation. It was sitting about 1/4" or so above the terra cotta before I stood on it.

Short story long, the liner itself is pretty heavy (approx. 60#) does anyone see any issues with the extra downward pressure I put on the top of the insert? I feel pretty comfortable with the rest of the install, we took our time and double/triple checked everything else as we went along.

Thanks,

Matt
 
You should be fine.
 
Isnt the liner hanging from the top plate? that really is how it should be done
 
The cap is not touching the clamp at all, just pushing down on the insulation. It was sitting about 1/4" or so above the terra cotta before I stood on it.

We need to know what that means?
 
We need to know what that means?

So when I went to put the chimney cap on, there was excess flex liner, liner insulation and wire mesh around the insulation. That wire mesh was held in place with a band clamp. I had to move the band clamp down the flex liner some and cut the excess insulation/wire mesh in order to get the cap over the flex liner. I moved the band clamp down to just below the top of the existing terra cotta liner and cut the excess flex liner insulation. Unfortunately, because I was trying to rush things, I did not cut the extra insulation far enough down. The result was that the chimney cap sat on top of the liner insulation instead of the terra cotta liner as it should. I tried pulling up slightly on the flex liner but because the cap was resting on the insulation/band clamp, it would not budge. In order to get the chimney cap to seat properly on the top of the terra cotta liner, I ended up standing on it and tightening everything down. The end result is that instead of the liner being "suspended" by the chimney cap, it is being somewhat compressed by the chimney cap pushing down on the excess insulation/band clamp.
 
What you want is no clamp on that liner and insulation when you install the cap. Don't know why it was on it in the first place. So...

Take the terra cotta top plate off.. Take that clamp off of the liner/insulation. Strip six inches of the insulation off of the top of the liner. Pull the liner into the clamp in the collar of the terra cotta cap.. Clamp the liner to the cap. Settle the terra cotta cap to the top of the tile liner. Trim the liner even with the top of the inside flue opening of the cap. Tighten the bolts to the flue tiles..

Go down and have a beer or beverage of your choice.
 
If the top plate is merely pushing down against the insulation, you're fine. As long as the top plate it tight. Did you run a bead of silicone where the top plate rests on the old tile liner top edge?
 
I agree with hog i think it is no big deal i would probably fix it but i dont think it will cause any problems. I just want to check you did put the liner right side up didn't you it really does matter with heavy wall
 
My liner sticks out 2" through the top plate. When I did mine they told me the liner would grow & shrink with temp fluctuation up to 1". seems like you have yours captured?? maybe impedeing the thermal expansion?? IDK, Just going on what I was told when I did mine..
 
I'll try to answer some of the above questions the best I can.

What you want is no clamp on that liner and insulation when you install the cap. Don't know why it was on it in the first place. So...

The insulation and clamp were there from then initial "insulating" of the liner on the ground. I ran the insulation and wire mesh a little long intentionally knowing that once I dropped the liner down the hole there would be no turning back. I knew if my measurements were off a little, I could always cut back the insulation but I was pretty sure I couldn't add any more later. The problem occured when I didn't cut enough back. The clamp is there to hold the mesh in place while it is stretched tight in the initial insulating process. After I dropped the liner, I probably could've removed the clamp but I figured that would cause the mesh to drop down the chimney and bunch up at the bottom. Again, probably not an issue as the mesh is really only there to protect the insulation from damage while it is being dropped down the chimney. In the end I left it on because I didn't want the mesh to bunch up at the bottom of my chimney.

If the top plate is merely pushing down against the insulation, you're fine. As long as the top plate it tight. Did you run a bead of silicone where the top plate rests on the old tile liner top edge?

Well, it is pretty much just pushing down on the insulation but the insulation is being bunched up/held in place by the band clamp from the mesh. Which I think is also putting some downward pressure on the liner itself. The top plate is tight and doesn't seem to have moved any in the last couple days but I haven't gotten on the roof yet to verify. I can see the cap pretty well through a window on my second floor. I did run a bead of silicone on the top edge of the terra cotta tile. I'm going to get up there in a little bit to double check everything.

I just want to check you did put the liner right side up didn't you it really does matter with heavy wall

I'm pretty sure I did. There was a blue arrow painted on the liner and something resembling the word "up". The arrow was fairly clear, the other part not so much! I dropped it with the arrow pointing up.

My liner sticks out 2" through the top plate. When I did mine they told me the liner would grow & shrink with temp fluctuation up to 1". seems like you have yours captured?? maybe impedeing the thermal expansion?? IDK, Just going on what I was told when I did mine..

I cut mine flush, not because I should have but because I was trying to hurry before it got completely dark and wasn't thinking. I also thought about thermal expansion but the cap itself has a band clamp to secure it to the liner. I contacted Fireside Chimeny Supply about the cap because the clamping system was different than what they sold in their "Heavy Wall Liner Flex Kit" and they actually recommended putting in a couple of screws as insurance to prevent the liner from slipping.

In the end, I should've just waited until today to button everything up instead of rushing to get things done in the dark. I guess I just wanted to get it finished because we had been working on it all day.

Thanks for all the replies and suggestions guys. I really appreciate all the help.
 
I would go back up there, cut off more insulation and move the mesh clamp down to allow for expansion, otherwise the insulation and mesh clamp may hang up in the top plate hole as the liner expands, breaking the silicone seal between the top plate and chimney. You have a top clamp, then a storm collar above the top plate, right? I'd like to see some pics to clarify things, but looking at the 304 kit on the fireside site, I think I know what you have there...
Isnt the liner hanging from the top plate?
Here's a question, although it wouldn't apply to the OP's insert; When the stove is rear-vented, do you support the liner at the bottom too? I have a couple of concrete blocks under the bottom of the tee to keep the expansion from happening in the downward direction...
 
Here's a question, although it wouldn't apply to the OP's insert; When the stove is rear-vented, do you support the liner at the bottom too? I have a couple of concrete blocks under the bottom of the tee to keep the expansion from happening in the downward direction...
Yeah if it is rear vented into a fireplace i will usually support it from the bottom somehow.

I'm pretty sure I did. There was a blue arrow painted on the liner and something resembling the word "up". The arrow was fairly clear, the other part not so much! I dropped it with the arrow pointing up.
Good i just though i should check
 
You have a top clamp, then a storm collar above the top plate, right? I'd like to see some pics to clarify things, but looking at the 304 kit on the fireside site, I think I know what you have there...

I didn't use their kit. The wife was pretty insistant about the look of the deluxe terra cotta chimney cap. I contacted Fireside about the compatability of the different components. They had no issues at all with using the heavy flex liner and the deluxe chimney cap together. The only thing they suggested was to put in a couple screws as extra insurance to prevent slipping of the intigrated band clamp. Unfortunately, I don't have any install pictures only a finished product but here it is.

Well, maybe not. For some reason I can't get my pictures to load but if you look up "Deluxe Terra Cotta Top Plate" at firesidechimneysupply.com you can see what I ordered. I just got on the roof and checked everything at it looks fine. I haven't fired the insert yet but there's no bending/buckling/buldging or seperating yet. It's supposed to snow tonight so I may have a fire. I don't know if it's going to snow here in town but it will in the mountains. That's close enough right?:)
 
Holy kamoly, they gotta lotta clay pots and caps! Now we really are gonna need some pics. ==c http://www.firesidechimneysupply.com/clay-chimney-pots.html

So this is the top plate you have? I've looked at the instructions, but still don't see how it works. Those band clamps are for clamping the liner at the top? If the liner expands (lengthens) it's going to push the top plate up off the terra cotta chimney lining, right? The clamp shown in the kit below clamps to the liner, which protrudes through the top plate; This supports the weight of the liner from the top, if you have to pull the stove out, but allows the liner to move up through the top plate if it expands.
flue_fit_top_pla_4cc77d0c096e8_1.jpg

Are these the components you have installed, except for the clay pot top plate and the rain cap? " Top plate, rain cap, support clamp, storm collar and appliance connector"
5.png
 
If the liner expands (lengthens) it's going to push the top plate up off the terra cotta chimney lining, right?
When installed correctly heavy flex collapses on it self and does not gain any length when it expands That is why you should pull it up relatively tight
 
When installed correctly heavy flex collapses on it self and does not gain any length when it expands That is why you should pull it up relatively tight
Well, I didn't do that, but by the time we pulled it up from the bottom through those turns, it was probably pretty much stretched out. ;lol
 
Holy kamoly, they gotta lotta clay pots and caps! Now we really are gonna need some pics.

They do have a lot of options don't they? That is pretty similar to mine, only real difference is mine came with a flip top rain cap/rodent screen. The band clamp is for clamping the liner at the top, that's why I called them. I also thought about the expansion causing problems but they didn't seem to have any concerns at all. I'm still having problems getting my pictures to load. Not sure what's going on there.

I'm very pleased overall with Fireside. The liner is super heavy duty and the cap is good quality - and it looks nice!:) Above all, their customer service is top notch.
 
I also thought about the expansion causing problems but they didn't seem to have any concerns at all.
If you have it pushed down that tight you may have problems with the expansion i would go up there and fix it if i were you
 
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