Insulating a liner, why does the insulation need to be overlapped?

[bholler]

ok good to know; i'll have to find a supplier that has everything in stock.

So for the install the liner will be supported by the transition plate from the top and the tee will be suspended ~10ft above the bottom of the chimney. Is there a trick to installing the liner with the transition plate to class a pipe?

I'd like to avoid having to drop the entire assembly in, check fitment, pull out and recut the liner if required. A regular top plate would allow for the liner to be pulled up/down through the plate, but the transition plate forces you to terminate the liner on the bottom side. So getting the distance correct is important.

Do liners have some amount of expansion/compression they can withstand? I doubt the liner is going to go in completely straight even if I measure the distance and cut correctly.

Measure mark and cut very carefully after stretching the liner out.

 

[neverstop]

Measure mark and cut very carefully after stretching the liner out.

is there a sweaty palms emoji? by stretching out do you just mean unroll it, or intentionally try to stretch the liner?

 

[bholler]

is there a sweaty palms emoji? by stretching out do you just mean unroll it, or intentionally try to stretch the liner?

If you are using midweight or heavy wall liner there is usually quite a bit of expansion

 

[begreen]

i had downloaded the duraliner catalog, but only saw short sections of oval or an option to ovalize the first 4' of the liner.

• rear exit - ~30" horizontal run to tee - there is an adjustable 90 degree on that run so it's not all horizontal
• 16' 10" long 5.5" uninsulated liner
  • tee has a cap on it
• stove calls for 6" liner and in rear exit configuration minimum chimney height should be "16 feet 6 1/8 inches (5.2m) from the top of the stove"
• chimney is exterior extends to ground level, stove is on 2nd level

Sorry, I was away for the weekend. DuraLiner oval rigid comes in 12, 24, 36, & 48" lengths. They make an oval tee with a round takeoff for the rear exit connection to the stove. The horiz. connection should be pitched upward toward the liner at 1/4" per foot.

 

[neverstop]

If you are using midweight or heavy wall liner there is usually quite a bit of expansion

Looking at the installation instructions for the olympia hybrid liner it says:
"For ArmorFlex/Hybrid Liner TM installations, it is recommended that the tee be secured and supported within the chimney".

There isn't really a way for me to accomplish this with my setup. Total liner length including tee will be roughly ~16 ft; is this a concern?

 

[Mijoka]

Assuming the insulation is 0.5" overlapping the liner increases the OD (at the overlap section) by 1.5". Is this overlap necessary?

My assumption is that the adhesive adheres to the liner better than the to foil insulation backer, but even if that is incorrect a 1" overlap isn't going to provide significant increase in holding force. If anything it could provide an easier point for peel-back of the insulation over time.

For one thing, that thin liner expands and contracts a lot, so maybe it's because of that. I've always wondered about the use of a spray adhesive to adhere the insulation to the liner. Perhaps when covered with a layer of insulation in can only smolder until it has burned away. If that product was sprayed on an uninsulated area of the liner, would it be a fire risk?