hi there i just wanted to ask what the best insulation would i need to keep the heat out during the summer and the heat in during the winter months?I have a loft and will start to think about doing it up soon,the apex is the area to be insulated as the floor area has rockwool down already,thanks Lloyd
insulation
- Thread starter spoonse
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Foam board insulation i.e. Celotex or Kingspan.
You will also need to think about ventilation also.
You will also need to think about ventilation also.
M
marsaday
i am also planning on doing this next yr, but am looking into using tri iso.
we dont have a problem with head room and so this isnt an issue. it just seems tri iso is much quicker to fit and is cheaper.
Any comments on this method. i can get approval no problem by the inspector using this product.
we dont have a problem with head room and so this isnt an issue. it just seems tri iso is much quicker to fit and is cheaper.
Any comments on this method. i can get approval no problem by the inspector using this product.
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@marsaday
I know you've written that your BC will approve the Tri- Iso and if that's all you are interested in then fine.
If however you want insulation, I would suggest doing some critical thinking about these multi-foils.
If they really were so wonderful, being clean, thin and flexible then where do you think they would be taken up very quickly ?
Well, in aeroplanes which are of course very tight on space and Boeing/Airbus not short of a few bob..
But no, they don't use multi-foils but, I believe, an insulation called aeroel which is approx 3 times better than glass-fibre per inch but HUGELY more expensive.
I , personally do not believe the claims of Tri-Iso and the rest. The French equivalent of the BRE tested TRi-Iso, found the claims significantly overstated and were only able to achieve about 1/3 of the insulation value claimed.
I know you've written that your BC will approve the Tri- Iso and if that's all you are interested in then fine.
If however you want insulation, I would suggest doing some critical thinking about these multi-foils.
If they really were so wonderful, being clean, thin and flexible then where do you think they would be taken up very quickly ?
Well, in aeroplanes which are of course very tight on space and Boeing/Airbus not short of a few bob..
But no, they don't use multi-foils but, I believe, an insulation called aeroel which is approx 3 times better than glass-fibre per inch but HUGELY more expensive.
I , personally do not believe the claims of Tri-Iso and the rest. The French equivalent of the BRE tested TRi-Iso, found the claims significantly overstated and were only able to achieve about 1/3 of the insulation value claimed.
@mointainwalker, debate has thrived regarding the effectiveness of this insulation and its acceptance or not by BC for many years on this forum although it widely is nowadays. Its been certified by BMTrada, part of the Trada Group, a fairly well respected body within the industry as equivalent to 210mm of mineral wool insul. Whilst I find myself at a loss to many of our own standards within the building industry in Blighty (quality of workmanship wise not standards per-sea) frankly, given the kind of queries we get from the other side of the Channel, French building standards seem to have a lot to be desired as well. Can you back your statement up? I am no aero engineer and would consequently be completely unqualified to suggest what insulation should be used in aeroplanes, are you? As a spacesaving insulation it seems pretty effective solution.
Correct. You will require an air gap above the insulation, this air gap will need venting to the outside.
M
marsaday
noseall
Will i need air vents in my roof if it is just tile which is back pointed. there is no membrane on there at all?
Will i need air vents in my roof if it is just tile which is back pointed. there is no membrane on there at all?
M
marsaday
Regarding multi foil:
What about going for 50mm of kingspan between the rafters and then using the multifoil under it.
What about going for 50mm of kingspan between the rafters and then using the multifoil under it.
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@ Freddy - the following is taken from
www.cstb.fr/filesadmin/documents/actualites/communiques-dossiers-presse/DP280_11_07_PDF.pdf
The CSTB is the Centre Scientifique du Technique du Batiment which I take as an exact equivalent to the Building Research Establishment.
The translation is mine.
" In a research programme ( PREBAT) funded by the French state, via ADEME ( French Environmental and Energy Agency ) two studies on reflective-foils were commissioned from the Ecole des Mines de Paris and the CSTB. A joint communique was published on 21/3/2007 in Aix-les-Bains.
Four members of the SFIRMM thin-foil producers association, whilst not contesting the scientific results of the communique which shows that multi-foils were not able to reach an insulation value of R2m2K/W contest the scientific value of these in-situ tests.
( I don't really understand the logic of that last sentence unless it means they contest the methodology - translator's note )
The CSTB tests were carried out on two commercially available products: one multi-foil - produced by a member of the SFIRMM producers association- which had no technical accreditation and a commercial glass-fibre with CE certification made by URSA, 2 x 100 mm with an R of 5m2K/W.
Two identical test cells ( basically houses or parts of houses - translator's note ) were used. It was not economically possible to test all installation variations so the optimum installation conditions were chosen.
This was a vertical wall for the wool and a wall and a roof for the thin-foil. The latter two both had two closed air-gaps. If, as specified by the manufacturer, the outer air-gap had been open to the atmosphere, the result would have been significantly worse.
The test were carried out at the CSTB site in Champs-sur-Marne between mid-February and mid-April ( year not mentioned - translator's note) with monitoring in accordance with EN 17025.
The results of the tests show that under optimal conditions, thin-film insulation cannot better -or even reach - an insulation value of R2 m2K/W.
( Later in the communique it confirms test values of R5 m2K/W for the wool - translator's note )
End of translation
I have read another CSTB report which said that under normal conditions of installation it is impossible to come close to even these low values because any gaps greater than 1 mm between sheets( from memory) significantly reduce the insulation value . Why that should be I don't understand.
As for aeroplanes, I am also unqualified, but, when I was seeking out information on best available insulation for my own use, the logic ( as I see it) about planes needing the best possible insulation occured to me and I posed the question on an aircraft-engineering forum and got the answer about aerogel, which from memory is 200% better than glass-fibre but very costly.
French building regs are very strange. As an individual renovating an old-barn, I don't have to adopt any current regulations at all ( although professionals must ). However even as far as professional are concerned, I do not believe there is any such thing as a BCO - it is all self-certified.
Most strangely for me, when my plans were submitted for approval, new floors I was creating in a 6 m high space, were represented as lines. The authorities didn't know if they were going to be wood, concrete or papier-mache and there was not a single number or calculation attached to it. This was for a floor 9.5 m x 6.3 m.
www.cstb.fr/filesadmin/documents/actualites/communiques-dossiers-presse/DP280_11_07_PDF.pdf
The CSTB is the Centre Scientifique du Technique du Batiment which I take as an exact equivalent to the Building Research Establishment.
The translation is mine.
" In a research programme ( PREBAT) funded by the French state, via ADEME ( French Environmental and Energy Agency ) two studies on reflective-foils were commissioned from the Ecole des Mines de Paris and the CSTB. A joint communique was published on 21/3/2007 in Aix-les-Bains.
Four members of the SFIRMM thin-foil producers association, whilst not contesting the scientific results of the communique which shows that multi-foils were not able to reach an insulation value of R2m2K/W contest the scientific value of these in-situ tests.
( I don't really understand the logic of that last sentence unless it means they contest the methodology - translator's note )
The CSTB tests were carried out on two commercially available products: one multi-foil - produced by a member of the SFIRMM producers association- which had no technical accreditation and a commercial glass-fibre with CE certification made by URSA, 2 x 100 mm with an R of 5m2K/W.
Two identical test cells ( basically houses or parts of houses - translator's note ) were used. It was not economically possible to test all installation variations so the optimum installation conditions were chosen.
This was a vertical wall for the wool and a wall and a roof for the thin-foil. The latter two both had two closed air-gaps. If, as specified by the manufacturer, the outer air-gap had been open to the atmosphere, the result would have been significantly worse.
The test were carried out at the CSTB site in Champs-sur-Marne between mid-February and mid-April ( year not mentioned - translator's note) with monitoring in accordance with EN 17025.
The results of the tests show that under optimal conditions, thin-film insulation cannot better -or even reach - an insulation value of R2 m2K/W.
( Later in the communique it confirms test values of R5 m2K/W for the wool - translator's note )
End of translation
I have read another CSTB report which said that under normal conditions of installation it is impossible to come close to even these low values because any gaps greater than 1 mm between sheets( from memory) significantly reduce the insulation value . Why that should be I don't understand.
As for aeroplanes, I am also unqualified, but, when I was seeking out information on best available insulation for my own use, the logic ( as I see it) about planes needing the best possible insulation occured to me and I posed the question on an aircraft-engineering forum and got the answer about aerogel, which from memory is 200% better than glass-fibre but very costly.
French building regs are very strange. As an individual renovating an old-barn, I don't have to adopt any current regulations at all ( although professionals must ). However even as far as professional are concerned, I do not believe there is any such thing as a BCO - it is all self-certified.
Most strangely for me, when my plans were submitted for approval, new floors I was creating in a 6 m high space, were represented as lines. The authorities didn't know if they were going to be wood, concrete or papier-mache and there was not a single number or calculation attached to it. This was for a floor 9.5 m x 6.3 m.
Hi mointainwalker, that does make for some interesting reading although I have to say I'm not really any more convinced one way or another, in Actis's defence the tests were carried out under laboratory conditions rather than 'real life' conditions which is how the Trada tests were carried out.
As for aircraft insulation, its thermal properties are only one important factor, there are all sorts of standards aircraft insul needs to adhere to, building and aircraft insulations are two different types of insulation which are not designed to be interchangeable or to compete with each other and its unfair (and irrelevant) to consider them as being in any way comparable.
As for aircraft insulation, its thermal properties are only one important factor, there are all sorts of standards aircraft insul needs to adhere to, building and aircraft insulations are two different types of insulation which are not designed to be interchangeable or to compete with each other and its unfair (and irrelevant) to consider them as being in any way comparable.
actually i have a load of insulation board which is 50mm thick 600x2.4 in size but its a thing that goes under felt roofing on flat roofs.Its totaly rigid and looks exactly like any kingspan boards but without the silver on it,is it ok to use?
and will there not be enough air coming in under the tiles and up through the slate felt ?especially if there's a gap left when insulating
and will there not be enough air coming in under the tiles and up through the slate felt ?especially if there's a gap left when insulating
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@ spoonse. See no reason from insulation point of view why your board cannot be used. Not sure about the ventilation aspect.
@Freddy
Gosh, you're a hard man to convince.
The BRE did a hot-box test on Actis and got results around R 2. Actis said
"Ah, but you can't use the traditional test method on our reflective product."
This French test seems to have been an attempt to clarify matters using witness-testing carried out by two leading research-institutes of long-standing and the results are similar to the BRE hot-box .
Don't forget that it would have been beneficial to French economic interests to have given a positive report.
I wrote that the tests were carried out "in houses or parts of houses" no mention of labs.
Still unconvinced ?
I have to say that I am now critical of these products because it's my opinion that the advertising by the producers is designed to mislead and cheat the consumer.
A big play is made of the product being only 30 mm thick , but they don't mention the 2 x 25 mm air-gaps , effectively making it 80 mm thick, until it's bought and you unwrap it to see the instructions.
@Freddy
Gosh, you're a hard man to convince.
The BRE did a hot-box test on Actis and got results around R 2. Actis said
"Ah, but you can't use the traditional test method on our reflective product."
This French test seems to have been an attempt to clarify matters using witness-testing carried out by two leading research-institutes of long-standing and the results are similar to the BRE hot-box .
Don't forget that it would have been beneficial to French economic interests to have given a positive report.
I wrote that the tests were carried out "in houses or parts of houses" no mention of labs.
Still unconvinced ?
I have to say that I am now critical of these products because it's my opinion that the advertising by the producers is designed to mislead and cheat the consumer.
A big play is made of the product being only 30 mm thick , but they don't mention the 2 x 25 mm air-gaps , effectively making it 80 mm thick, until it's bought and you unwrap it to see the instructions.
I understood that their (Actis) defence was that when tested in 'real life' conditions it was equal to 210mm mineral wool and I also understood that this how the Trada test was carried out which seems to verify what Actis have said but I do hear what you're saying.
Hehe, thats not just your opinion, there was a complaint made against Actis sometime ago for misleading information in their advertising that was upheld by the ASA.
Hehe, thats not just your opinion, there was a complaint made against Actis sometime ago for misleading information in their advertising that was upheld by the ASA.
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Freddy
I am afraid that I have a suspicious mind.
I believe the 2006 tests were carried out at the Actis test centre in Limoux.
If this were the case then there is nothing stopping the site owners installing secret heating-circuits/ electricity-supplies that would be untraceable.
It is my experience that people generaly expect other people to be honest and don't start ripping out walls etc - unless you're checking Iranian /N Korean nuclear facilities - when undertaking this kind of study.
Actis was also started by a single entrepreneur and having worked for three self-made millionaires, I can safely say that they are a special breed whose regard for norms of behaviour is scant.
All the above is, of course, my own speculation, having no inside knowlwlege of multi-foil companies but still would not buy any of their products.
By the way, looking at an Actis ad' , they only recommend their product under-roof. If they do that, what stops them recommending in walls ?
I am afraid that I have a suspicious mind.
I believe the 2006 tests were carried out at the Actis test centre in Limoux.
If this were the case then there is nothing stopping the site owners installing secret heating-circuits/ electricity-supplies that would be untraceable.
It is my experience that people generaly expect other people to be honest and don't start ripping out walls etc - unless you're checking Iranian /N Korean nuclear facilities - when undertaking this kind of study.
Actis was also started by a single entrepreneur and having worked for three self-made millionaires, I can safely say that they are a special breed whose regard for norms of behaviour is scant.
All the above is, of course, my own speculation, having no inside knowlwlege of multi-foil companies but still would not buy any of their products.
By the way, looking at an Actis ad' , they only recommend their product under-roof. If they do that, what stops them recommending in walls ?
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