Installation series: 3/4 Insulation

[@LRDefender1968]

Great series guys, really informative! Kind regards Tony

[@user-ii9ns5sp8o]

I totally agree with your thoughts on insulation. The big push towards insulating all buildings will cause structural and health problems... Thanks for your advice. I'm about to have a wood burning stove fitted into a large stone chimney.

[@paulshaw4382]

Great video and explanation as usual thanks guy's. As we are mid point in burning season be good to have a video on operating temperatures and best practice to keep everything burning at its most efficient as it's usually just flicked over so a good explanation on this part of wood burning would be helpful to many I'm sure. It's great you actually tell it in layman's terms which is very easy to understand its great getting more information on all aspects of stove operation.

[@TheTortoise]

Great suggestion!

[@dannykimble7671]

I’m about to line my chimney & was going to insulate it with vermiculite but now you got me thinking, I thought it might help stop it rattling around when you sweep it, also it’s not straight up & down got two 45 deg bends, oooh lots to think about. Thanks for your advice & plain speaking.

[@compostjohn]

OK, interesting. There is another chimney lining/insulation which I wholeheartedly recommend. It's insulated concrete. The flue has a deflated 'sausage' placed into it and a base register plate put in, and the sausage inflated until it's really quite turgid. Holes are made just above the fireplace, in the wall in the first floor above and in the roof space, and insulated concrete pumped into the bottom hole. The sausage is centred so the concrete flows into the old chimney, filling any spalling bricks and loose mortar. When the concrete is up to the base of that hole, it is bricked back up and the concrete delivery tube taken upstairs to carefully fill in the next section, again ensuring the sausage is central and concrete flows into all the crevices, helping to strengthen and stabilise the chimney. The process then transfers to the loft space, and finally is finished from the roof, putting it around the sausage as it sticks out of the chimney. The sausage is kept inflated for 24 hours, and when the concrete is hard, deflated and pulled out. This creates a really smooth tube which heats up very quickly and gives a really strong draw. We used a company called Chimneycrete in the 90s to line a flue in a 1900 mid terrace, and put a Clearview Vision under it. When we moved in 2001 to a 1930s house with two ground floor flues, we got both lined by Chimneycrete and put the Vision in the large lounge/kitchen and a Clearview Pioneer in the smaller front room. Both flues suck really hard. They are a doddle to clean. We don't use any other heating in the house other than these 8Kw and 4.5Kw stoves. It's disruptive to have to re-plaster where the holes were created - but oh boy, the result is just wonderful!

[@TheTortoise]

They will allow you to stabilise a damage chimney with this, but nowadays it’s not generally a solution for stoves. HETAS will typically require a metal flue to be fitted within one of these now.

[@compostjohn]

@@TheTortoise Are you saying that you can't choose an insulated concrete liner? I think they're an excellent solution - never need replacing, work wonders! And how would you get a metal liner down the concrete flue? Maybe I'm misunderstanding you.

[@TheTortoise]

Ordinarily these were done to stabilise a chimney and typically they would be set up for an open appliance (so a minimum diameter of 8”). Generally now they won’t want a liner being any more than 1” larger than the outlet size of the stove, and fitting a 6” one of these for example is a little too permanent to recommend. You can imagine if you were to fit a 6” one it would restrict the use to only closed solid fuel appliances. If you ever wanted to convert to gas, this would have its own challenges, and open appliances would be permanently off the table. These have their uses, but because of modern regs they’re now a bit too restrictive to recommend as the main liner. I would definitely still have one as they definitely have their uses, but I would prefer to keep as larger diameter as I could in the chimney and then stick a metal flue within it that I could remove if ever I wanted to. Also I have been to several houses where they have failed (granted this was after a few decades, but sadly nothing lasts forever), and trying to remove them is done with a flail and it is no mean feat. This is the lovely thing about metal flues in that they just lift out, but I agree these are a fairly elegant solution particularly if/when a chimney has begun to lose some of its structural integrity.

[@atopdesigner]

Great series and I've been waiting for this one as we are pending a flue install and are being pushed to include a £1k thermal blanket. It is an exposed west facing Victorian red brick gable albeit in a town not the open country. Seems like a heck of a lot of money for little or no benefit.

[@TheTortoise]

I have to admit, I’m not sure what this product is, but the cost is definitely off putting 😬. With insulation it is always worth asking why your property needs it. I’m quite keen to listen if there are specific reasons, but if the reasons are more generic, then that would tend to put me off. As I say these things shouldn’t be used willynilly, it’s generally an answer to a specific problem.

[@Begreen9]

In US and Canada, insulation is always required unless the outside of chimney has 2" clearance from any and all combustible, right up through the roof if it is an interior flue. If it is an exterior chimney then 1" clearance from combustibles is required. Almost always and insulated liner will perform better and stay cleaner if insulated. Most typically, liners here are either wrapped with a 1/2" thick kaowool jacket that is then held in place with a stainless mesh sock. Or one can purchase preinsulated liner which has a stainless core and outer jacket with the insulation in between these two layers. FWIW, pour-in liner definitely is not preferred because it requires spacers at regular distances to prevent the liner from touching the chimney interior. It also make a god-awful mess if the liner needs servicing or replacement.

[@huwbishop6995]

I'd imagine you would get more benefits from insulation in the North of America and Canada, as your winters are colder than ours. Damp is the biggest issue here. It rarely gets sub zero (Celsius) but it rains a lot more. In sw wales we have had near enough 300 days where it has rained at some point during the day. So our chimneys are warmer but damper, where as yours are colder and dryer.

[@Begreen9]

@@huwbishop6995 We are in a similar climate in the Pacific NW. The same rules apply. Mild climate zones often need insulation to improve draft, especially if the chimney is on the shorter side. Draft in general is weaker when heating in milder temps. Also, some catalytic stoves really require properly insulated flue systems to reduce buildup.

[@huwbishop6995]

​@@Begreen9 My chimney is about 30ft, not insulated, but inside the property. Draws really well. I've seen catalytic stoves, it's really interesting as we don't really see them here. We have defra and eco ready, which restricts how much you can close the air. It would be interesting to run an equivalent side by side and measure emissions.

[@olliec1319]

Really useful, thank you. I never realised the royal family had immunity from building regs! I was wondering if it's worth having 8 inches of rockwell or something similar above the register plate as insulation from the cold when the wood burning stove isn't being used?

[@TheTortoise]

The best thing is to actually encourage some air exchange during prolonged lack of use. This is where insulation can work against you. Generally the best advice is to vent the register plate and leave the vents on the stove open, as this will allow air exchange in both the chimney and liner, which keeps things drier.

[@olliec1319]

@@TheTortoise Thanks. I appreciate your input. I've been wondering that for ages. Intuitively we'd lose a lot of heat where the register plate is but I guess airflow trumps heat.

[@TheTortoise]

It certainly can do. 😅

[@danielthompson6552]

Thanks for your videos! Similar question to someone else… I’m currently suffering with heat going up the chimney rather than into the room. Think it’s because the registry plate is thin, chimney is large and there is a recess before the registry so heat may be getting trapped above log burner… so im thinking of adding Rockwool above the registry plate to insulate it better. Would this be a safe thing to do and within the regulations (England)?

[@TheTortoise]

I will use Rockwool when fitting stoves at home quite a lot. In fact, when fitting inset stoves, I do this quite a lot for the same reasons as your intention.

[@paulhowell8519]

Hi just for info LECA stands for lightweight expanded clay aggregate.

[@TheTortoise]

😆 yea I looked it up after filming 👍

[@SS-vz9iv]

Great video explanation thank you! Got a question specific to my property.. you mention part and fully exposed stacks but could you just clarify about flues in gable walls - mine is a circa 1900 end terrace with a single brick inside the flue facing east/ south east. I totally agree with you about older building fabrics and damp but just curious on what you'd advice for that sort of scenario. Many thanks 😊

[@TheTortoise]

To be honest I would ideally want to try it without any insulation at all (initially). There’s a chance that things may need to change in the future, but generally I’d expect this to be the best answer. Our house is not dissimilar to yours and due to that I watch the tarring issue in both the open fire and one of the lined chimneys. There is no big issue in my case, the chimneys can be a little slow to start, but this is definitely the lesser of the 2 potential evils.

[@SS-vz9iv]

@TheTortoise Thank you, I really appreciate your advice. It's just the fact it bridges a lot, and a shame it loses a lot of heat out of that external wall. It does draw well being on top of a hill though, and I'm happy staying away from insulation if possible as it's a very porous soft brick and doesn't need extra moisture problems. Thanks again and great series 😊

[@alexmacdiver]

Very informative series.... Could you make on on small business & income Tax 😁

[@TheTortoise]

😅 nice idea. I’ve been watching a bit of “Gary’s Economics” recently. Interesting guy, but some scary predictions 😬.

[@joncoke8208]

I fitted our own inset cassette gas fire, its 7kw but does not heat the room at all, im sure when i fitter i didnt insulate/ vermiculite the chimney or fit the register plate,is it worth stuffing insulation around the inset fire?

[@TheTortoise]

Can be, but each situation, fireplace and stove is different. Bear in mind that with gas appliances you’re often given the input KW, which will be significantly larger than the output KW. Gas generally doesn’t have a huge output, but they do have wonderful convenience!

[@marcussheldon9220]

Hi, does a flue need to be insulated to create a better draw ?

[@TheTortoise]

Not always. This video goes through its purposes.

[@ianscottuk]

Is a standard flue single or double walled? I was guessing the double walled was to give a degree of insulation?

[@TheTortoise]

Stainless steel liners for solid fuel use are always at least double skinned, but not insulated. The purpose of layering the metal up is to do with: Making them more sealed Resilient to higher temperatures Stronger More durable And last longer Insulation is separate to this.

[@KavanOBrien]

Whiskey time guys , I think I understood but only think so , this house which I was brought up in used to have a coal fire and we also burnt logs open fire type, I took that out many years back and put in a gas fire well we all make mistakes , we never had a lining at all and the heat from the fire used to heat the hall and stairs and landing because one could feel the heat in the walls so putting a lining in would reduce the heat in the house if I got a small stove ? Could I not get the stove and not use anything except a small pipe coming out of the stove that would just go up the chimney a couple of feet , so the stove you’re sitting in front of on your videos what have you got going on , do you have a liner or not , you both need to restrict your whiskey intake probably what would help = less messages from me ,

[@TheTortoise]

Both the fireplaces with stoves in are lined, the open fire in some of the videos is not lined. Just the original 250 year old chimney.

[@KavanOBrien]

@@TheTortoise Do you have any plans in upcoming videos in regards to the linings because I did catch you saying that one has to be careful with some of them when sweeping because that are quite fragile or thin in their construction , sounds as though as with the fire itself some are better than others , obviously with your knowledge and experience in this field is there a list of ones to buy and ones to avoid, maybe title the video = clean sweep.

[@EddRandomCrap]

🥶