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

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With the proposed changes, the volume of gases will increase slightly. If the height remained the same, the velocity of the gases would decrease a little, but adding 4 ft and insulating the liner should make a notable improvement. Is there an insulated block-off plate sealing off the damper area?

Note that sometimes there are other issues like the location of the chimney with respect to the house roofline and geographic location. What is the current misbehavior that is being addressed? Does it always happen, or just under certain conditions? For example, if smoke rollout is a problem, is this mostly with cold starts when outdoor temps are milder? Or all the time?

There is no damper, it's not a fireplace just a brick hearth/backsplash with the thimble running through the brick into the external chimney. liner is connected via a tee.

currently chimney adhere's to 10-2-3 rule. the picture below is of the chimney/surround roof. the leaves in that picture are deceiving; that tree limb is 25+ft away from the chimney. The tree is probably 50+ft away but it is tall 80+ft.

• smoke rollout is always a problem regardless of hot reload or temps below 10F
• back-puffing, problems initiating draft on cold starts
• the most annoying issue being once secondary combustion is established (propane grill effect) the stove inevitably fills up with off-gassing and then secondary flames start igniting around the front airwash and temps rise very quick
  • this might be a side effect of not being able to turn down the primary air early enough without getting back puffing.

 

[begreen]

A picture is worth a 1000 words. The configuration of the 1 story roof next to a 2 story can be troublesome, especially with winds coming from that side.

A non-commercial service in support of responsible home heating with wood - How Wind Affects Chimney Performance

The Wood Heat Organization was formed to support the public in the responsible use of wood energy in the home. We fulfill our mandate by providing reliable information, by conducting research into wood heating-related issues and by representing the public interest in discussions of policies that...

woodheat.org

 

[neverstop]

A picture is worth a 1000 words. The configuration of the 1 story roof next to a 2 story can be troublesome, especially with winds coming from that side.

A non-commercial service in support of responsible home heating with wood - How Wind Affects Chimney Performance

The Wood Heat Organization was formed to support the public in the responsible use of wood energy in the home. We fulfill our mandate by providing reliable information, by conducting research into wood heating-related issues and by representing the public interest in discussions of policies that...

woodheat.org

Honestly when it was windy last year and the secondaries were going I saw them get more intense. Most back puffs were due to me turning down the air, it was very finicky between keeping the fire going and not having extreme out gassing during secondaries. Not to say some couldn't have been from that.

So are you saying I'm just screwed? Or i may have to increase chimney height more than intended to get it off that dead zone?

 

[begreen]

Just saying that this can add to the challenges. You are on the right course to try and improve the situation.

 

[neverstop]

Finally got up on the roof. I was off 1" on internal flue dimensions it's 6.75"x11".

The old liner came out really easy. I was also able to confirm that the clay tiles aren't mortared to the brick. Top tiles need to come out regardless so I broke a small section out with a ball peen hammer.

So now the question is go 4.5x9.1 with insulation or break out the tiles and go with an insulated 6in.

 

[EbS-P]

Finally got up on the roof. I was off 1" on internal flue dimensions it's 6.75"x11".

The old liner came out really easy. I was also able to confirm that the clay tiles aren't mortared to the brick. Top tiles need to come out regardless so I broke a small section out with a ball peen hammer.

So now the question is go 4.5x9.1 with insulation or break out the tiles and go with an insulated 6in.

If it’s a straight shot down or maybe just one offset I’d just go with the oval. Seems easier. I’m not sure what the price difference is but if oval is significantly more I might reconsider.

 

[neverstop]

If it’s a straight shot down or maybe just one offset I’d just go with the oval. Seems easier. I’m not sure what the price difference is but if oval is significantly more I might reconsider.

It's a straight shot, tiles don't look to have any major offsets by eye. But I'd only have 0.4" clearance on the long axis with insulation.

 

[EbS-P]

It's a straight shot, tiles don't look to have any major offsets by eye. But I'd only have 0.4" clearance on the long axis with insulation.

The insulation wrap is squishable but it needs overlapped. As long and there is no mortar sticking out anywhere I’d get the oval. If it doesn’t fit you going to have to break out, but I’d like to try and save myself that amount of work. It’s tight but it would be worth a shot for me. Get the kit that comes with the wire mesh sock and tie a rope to the mesh. It took two up on the roof on one person down pulling on the rope. The liner won’t be straight when sticking it down. You kinda have to straight up up but shove/pull the. Straighten up the neat section. Probably won’t be easy.

 

[neverstop]

The insulation wrap is squishable but it needs overlapped. As long and there is no mortar sticking out anywhere I’d get the oval. If it doesn’t fit you going to have to break out, but I’d like to try and save myself that amount of work. It’s tight but it would be worth a shot for me. Get the kit that comes with the wire mesh sock and tie a rope to the mesh. It took two up on the roof on one person down pulling on the rope. The liner won’t be straight when sticking it down. You kinda have to straight up up but shove/pull the. Straighten up the neat section. Probably won’t be easy.

Can I just leave the broken clay tiles in the bottom of the chimney? The clean out down there isn't functional with the liner. The tee/cap will be 10ft above the clean out location.

 

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@bholler or @begreen thoughts?

 

[bholler]

Can I just leave the broken clay tiles in the bottom of the chimney? The clean out down there isn't functional with the liner. The tee/cap will be 10ft above the clean out location.

You can. I always make a functioning clean out if possible though

 

[neverstop]

You can. I always make a functioning clean out if possible though

I'd need an extra 10ft of liner and with the layout it isn't possible to clean from the bottom. I'd also have to vacuum out the tee.

Any benefit to pre-insulated vs insulating myself in terms of longevity/performance? Also, I've been thinking about going with smooth wall to increase draft. Any draft increase I can get the better

 

[bholler]

I'd need an extra 10ft of liner and with the layout it isn't possible to clean from the bottom. I'd also have to vacuum out the tee.

Any benefit to pre-insulated vs insulating myself in terms of longevity/performance? Also, I've been thinking about going with smooth wall to increase draft. Any draft increase I can get the better

No real difference in durability between pre insulated and field insulated.

Smooth wall is good as long as it isn't the light wall 2ply crap. Don't buy that stuff

 

[neverstop]

No real difference in durability between pre insulated and field insulated.

Smooth wall is good as long as it isn't the light wall 2ply crap. Don't buy that stuff

Is this cheap 2 ply stuff? https://www.rockfordchimneysupply.com/chimney-liners/316ti-flexible-chimney-liners/316ti-flexible-chimney-liner-kits/smoothwall-flexible-custom-kits.php

 

[bholler]

Is this cheap 2 ply stuff? https://www.rockfordchimneysupply.com/chimney-liners/316ti-flexible-chimney-liners/316ti-flexible-chimney-liner-kits/smoothwall-flexible-custom-kits.php

Yes it is

 

[neverstop]

Yes it is

Do you have a suggestion for one that isn't trash? I need to transition to class a above the masonry chimney as well.

 

[bholler]

Do you have a suggestion for one that isn't trash? I need to transition to class a above the masonry chimney as well.

If you want smooth wall I would just go with a midweight liner.

 

[neverstop]

If you want smooth wall I would just go with a midweight liner

Is there a specific manufacturer I should look at?

 

[bholler]

Hybrid Chimney Liner

Buy Hybrid Chimney Liner at hearth stove and patio.The reason is simple, better quality, easier to install and will perform better than other chimney liner!

hearthstoveandpatio.com

This is the type of liner I am referring to

 

[neverstop]

Hybrid Chimney Liner

Buy Hybrid Chimney Liner at hearth stove and patio.The reason is simple, better quality, easier to install and will perform better than other chimney liner!

hearthstoveandpatio.com

This is the type of liner I am referring to

thank you. is it possible to mix and match liners with different brand's connection components? i need a longer snout than the olympia offers

 

[bholler]

thank you. is it possible to mix and match liners with different brand's connection components? i need a longer snout than the olympia offers

No you can't mix and match components. And you need a snout longer than 48"?

 

[bholler]

But really as long as you buy a listed liner from a reputable company the brand doesn't matter

 

[neverstop]

No you can't mix and match components. And you need a snout longer than 48"?

Only saw 10". Need 18". I'll check their site again

But really as long as you buy a listed liner from a reputable company the brand doesn't matter

And good to know, thanks

 

[bholler]

Only saw 10". Need 18". I'll check their site again

And good to know, thanks

They make snouts up to 48". But 18 and 24 are standard

 

[neverstop]

They make snouts up to 48". But 18 and 24 are standard

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.