Nice Install Video - UK

[ridemgis]

Interesting video on a UK stove install - some bits might be useful here in the US or Canada...

 

[begreen]

Nice work. Don't tell Ben, the liner's not insulated.

 

[agbagb]

Interesting video on a UK stove install - some bits might be useful here in the US or Canada...

Thanks for posting the video and for spotting some things that might be useful "other side off the pond". I can't believe it's 5 1/2 since I was last on here, time flys!!

Any questions or suggestions I'll be happy to answer (or take on board).

Begreen, I take," too insulate or not" is a (long running?) debate your having. I planning on doing a video with an inspection camera on the install I first posted about. 5 years on it could prove or disprove some myths.

Cheers
Andy (the I from idostuff)

 

[bholler]

Begreen, I take," too insulate or not" is a (long running?) debate your having. I planning on doing a video with an inspection camera on the install I first posted about. 5 years on it could prove or disprove some myths.

Not really a debate in the us it is required by code unless you have the required clearance from the outside of the chimney to any combustible materials. I insulate every liner i install regardless of code i find they work much better when insulated. Ad I urge everyone here to do the same. I have no idea what is required in the uk though

 

[agbagb]

Cheers Bholler, In the UK the debate seems to be about gasses cooling and condensing on the inside of the liner and forming tar. Some installers insist on insulation others say insulation is a good idea if the stack is external or a large portion of the stack is exposed to the cooling elements.

The UK regs dont specify insulation but there are distances from combustible materials that should be met. Most UK installations are in to existing masonry stacks that used to have open fires and as long as the gasses go up and out they don't actually need lining. I agree a liner improves the performance of modern stoves and helps to get a good initial draw, the extra benefit of insulation however is limited, the air surrounding the liner inside a stack is quite a good insulator.

It's one of those issues that I would like to get to some evidence on.

 

[bholler]

The UK regs dont specify insulation but there are distances from combustible materials that should be met. Most UK installations are in to existing masonry stacks that used to have open fires and as long as the gasses go up and out they don't actually need lining. I agree a liner improves the performance of modern stoves and helps to get a good initial draw, the extra benefit of insulation however is limited, the air surrounding the liner inside a stack is quite a good insulator.

Here a liner needs to go into a masonry structure. But unless you have 1" gap for an exterior chimney or 2" for an interior one. That liner needs insulated. In a chimney fire it is possible for enough heat to be transferred through that masonry to ignite the adjacent combustible material. The argument that air is a good insulator is only true if that air cant circulate at all. But in fact it can and because of that the heat will be transferred through that air and into the masonry structure. Yes that air space will absolutely reduce the amount of heat transfer but what about the spots where the liner contacts the inside of the chimney? And yes the cooling of gasses is a concern for me as well and that is why i insulate regardless of whether it is required by code or not.

 

[bholler]

the extra benefit of insulation however is limited

that is very debatable in my experience there is much less buildup in insulated liners

 

[begreen]

Not debating the safety value but we have seen many reports of very clean, uninsulated liners at the end of the season cleaning. Burning dry wood in a low-emissions stove with an interior chimney liner often equals a much cleaner flue, insulated or not.

 

[Oldman47]

If you look at the install involved, there was tons of room around that liner. In that situation I would have been tempted to use a rigid liner so I could be assured of lots of space around the entire length of the chimney. At that point the insulation really would be optional/personal preference. I mean think about it, the guy was standing in the old chimney to take the initial pictures and that was with the flex liner already hanging in place. Being a built from scratch chimney it has a lot more room inside than one with a 7 or 8 inch clay pipe liner.

 

[bholler]

Not debating the safety value but we have seen many reports of very clean, uninsulated liners at the end of the season cleaning. Burning dry wood in a low-emissions stove with an interior chimney liner often equals a much cleaner flue, insulated or not.

I agree begreen uninsulated liners can be burnt in a way that they don't get allot of buildup. So can clay liners or even unlined chimneys. But with insulation it is faster and easier to get to the proper temp and it will stay above the condensation point much better. I work on many liners that are uninsulated that the customer keeps clean and i work on insulated ones that are a mess as well. So no matter what your setup is you need to burn good wood and burn properly. But i have found that it is easier to burn properly with an insulated liner.

At that point the insulation really would be optional/personal preference.

Still needed for code regardless of the space around the liner. Unless you have the space outside the masonry structure. And in a space that large there is allot of air that you need to heat up so from a performance standpoint there is more reason to insulate. Safety wise yes if you stay off the walls it is much safer for sure.

 

[bholler]

It is still a nice install and a good video. It is much better than many i see the only issue i have is the insulation

 

[agbagb]

Thanks for the heads up on the US code, I've added a little note on the video and a comment pointing this way.

I mention on the full write up of the liner installation (previous video):

"I take a less dramatic view of the potential problem, supported by my own experience. Insulation of the flue liner is not essential if you use your stove properly and burn only well-seasoned timber, unless there is something peculiar to your chimney that would cause excessive cooling of the liner (e.g. It's against an exposed external wall, lots of bends, very long.) So for this job I'm not using any flue liner insulation."

I've not heard of insulation for protection in a masonry stack in the event of a chimney fire before. It would be interesting to know how well wraps would last at those temperatures and would an insulated liner be more susceptible to getting to the temperatures where a chimney fire is possible?

But code is code, or we have building regulations in the UK. So if it is a requirement it should be done.

 

[bholler]

It would be interesting to know how well wraps would last at those temperatures and would an insulated liner be more susceptible to getting to the temperatures where a chimney fire is possible?

yes they hold up just fine and no it does not contribute in any way to chimney fires. If it did it would not be a requirement of code and a recommendation from every American chimney professional organization and most liner manufacturers.

"I take a less dramatic view of the potential problem, supported by my own experience. Insulation of the flue liner is not essential if you use your stove properly and burn only well-seasoned timber, unless there is something peculiar to your chimney that would cause excessive cooling of the liner (e.g. It's against an exposed external wall, lots of bends, very long.) So for this job I'm not using any flue liner insulation."

I totally agree from a performance standpoint it is in no way essential but when i install liners i want to make them preform as well as possible and all of the testing shows that they preform better with insulation. If you choose not to as long as it is not a requirement then there is no problem that is your decision to make. But for me as a certified sweep i am required to follow best practices and code both of which call for insulation.

 

[bholler]

It is apparently also a recommendation from your chimney professional organization as well read on page 7 the section on Insulation is key

http://www.hetas.co.uk/wp-content/mediauploads/BFCMA-General-Guidance-10-12-12.pdf