Insulation questions - again

[woolybanana]

Two questions, maybe the same answer:

First, I am considering covering over the lambris ceilings of the banana house with placo and would take the opportunity to put in some extra insulation. I do not have much more than 5-7 centimetres to play with. What alternatives are there to rolls or sheets of rockwool under the placo to give maximum insulation svp?

Second, would like to do same with the internal walls of part of the house. What is best here please?

Thank you guys.

[Chancer]

Other than isolation mince where there is some controversy over its actual insulation properties, see below, the best courant  insulation material relative to its width is extruded polystyrene, its a shame that the placo doublage uses expanded polystyrene.

I have insulated my grenier with 17 layer isolation mince and am in the pocess of fitting out 2 studios in the roofspace, it seemd to keep the rooms realy cool in summer but I had no way of comparing it with if I had used traditional insulation.

However with the 22cm of snow that has remained here for the last  week or so I can do a comparison with the other houses by looking at the snow that remains on their roofs, most around here are very poorly insulted and melted the snow covering immediately, more recently built dwellings to the latest normes (24cm laine de verre) and those recently renovated still have a patchy covering whereas my roof is still completely white despite me using a propane space heater every day.

Not that it will count for anything if I have an energy efficiency diagnostique, the certificate will say zero insulation [:(]

[cooperlola]

Our experience pretty much reflects Chance's.  The stuff appears to work well but carries no tax breaks and does not count as insulation in any surveys. 

[woolybanana]

Did you lay it with an air gap or just on a surface?

[nomoss]

You can have cellulose insulation (outé de cellulose) blown in to any thickness you want, provided there is access above the finished ceiling. This has the advantage of completely filling the space, with no air gaps for thermal leakage.

I assume you propose rockwool above the placo ceiling, as it would be a bit unsightly under it? [:)]

Rockwool or glass fibre is a bit tedious to fit above a ceiling without leaving gaps, but the edges of the sheets can be taped together and a plastic film placed below them to stop air circulation. If you have sufficient height available you can use placo pre-insulated with a variety of materials and thicknesses - 20, 40, 80, or 100 mm of insulation on 10mm placo is commonly available, polystyrene is the lightest in weight for a ceiling.

The same insulated placo may be used for the exterior walls, insulation thickness depending on how much interior space you can afford to lose. If the walls are reasonably flat and sound, this may be glued on with "plots" of "mortier adhésif". If not it may be screwed to a metal armature or wooden battens.

I have insulated all my exterior walls with (glued on) placo + polystyrene, 40mm downstairs - to save space, 80 mm upstairs, ceilings already had 15cm glass fibre. We now successfully heat our house to 20º down, 18º upstairs, with a single 5.5KW pellet stove downstairs. RDC 65 m2, étage 51 m2.

 

[woolybanana]

Thank you all, more to think about.

[just john]

 THINSULEX I used this stuff on a friends renovation and we just stapled it to the rafters as per Architect; It was inspected by building control in UK and the guy made a bit of a fuss about whether it was approved until after a discussion with the architect, then we screwed foil backed plasterboard on top, taped and jointed it. He's still very pleased. Whereas  thinsulex installation requirements are a bit more involved . . .

[Chancer]

Re the air gap.

In my case practically none, I first laid some 2cm extruded polystyrene sheets between the madriers overlapping each other verically like tiles but of course under the tiles, and then stapled up the isolation mince, the tiles touch the polystyrene which in turn touches the foil insulation.

I then battened it out with 22mm battens and screwed the placo to that, so there is nominally an airgap between the foil and the placo but in practice it swells and sags between the fixings so not much in reality.

My best experiences with it have been with packed lunches both hot and cold, I sandwich the food tightly between 2 sheets of the insulation an then stuff it into a jiffy bag in my backpack, no airgap there but it works fantastically. I first got the idea when I saw it used in the top box of a pizza delivery mobylette!!

[woolybanana]

That may well be the route I shall have to follow given the space up there.

Thanks again everyone

[Théière]

From your other post in oil boilers:

[quote user="woolybanana"]

Thank you T, I shall try and find out about extruded later this week.

I am told the bubble based stuff has to have a 2 cm air gap either side to be effective. Did you install it that way? And that it is not recognized as an official insulation material if you need a thermal check?

[/quote]

Yes Wooly, it does seem the powers at be in France don't recognise it, give them some time, although the other major insulation producers may have bought the government off which is why in the UK multifoil has a tough time too, interesting that they will accept compressed damp rodent infested rockwool and laine de verre. I wouldn't use the bubble type as the bubbles will perish with time and extremes of temperature. There are other multifoils without bubble wrap in between. Yes air gaps are required as the info from JJ showed (excellent info btw).

[Quillan]

Wooly I did some basic research for an aquantance and have given some links below which you might find interesting.

http://www.energysavingtrust.org.uk/Home-improvements-and-products/Home-insulation-glazing/Solid-wall-insulation

Although this talks about 'rockwool' type insulation it does give some ideas about the savings possible etc.

http://www.ybsinsulation.com/products_wall_airtec-drylining.htm

What you are talking about is effectively 'dry lining' and adding insulation. This link shows how these modern multi layer, yet incredibly thin, 'sandwich' type stuff works. Basically you can get the same effect of 150mm of rockwool insulation with just 8mm (or less) of this stuff. Not only does it insulate but forms a moisture barrier as well depending on the version of the product you buy. Now the stuff in the link is not sold in France BUT there are companies producing and/or selling a similar type of product here, I know Brico Depot and Leroy Merlin had it last time I visited. A another thing for you to think about is that as you are considering doing the walls as well how much little effort rewiring will be. Basically you can do a 'first fix' surface mount before you put in the insulation, saves all that angle grind, filling etc.

[Théière]

This is sold in France, have a look at the website.

http://www.insulation-actis.com/presentation09.php?p=3&l=3&rub=5&vert=1&gamme=0

http://www.insulation-actis.com/produits.php?p=3&l=3&rub=40&gamme=0

[CeeJay]

I too am in a similar position as I have just converted the grenier and now need to insulate the exposed roof.

[IMG]http://i1140.photobucket.com/albums/n571/ceejay41/Picture001.jpg[/IMG]

I have in mind to fix extruded polystyrene blocks of 40mm thick between the rafters, which are roughly 80mm square and about 450mm apart then cover the lot with plasterboard.

I would appreciate advise as to whether it is necessary to put a vapour barrier in before I fix the plasterboard or if foil backed board would be sufficient. If this is so what is the French name for this type of board?

Apologies for the size of photo, my first use of Photobucket!!!!

[Wilko]

The link is to a thread on the Greenbuilding forum which has been running for 4 years re multifoil insulation.. This link should show the last page and a couple of guys have posted an overview, saves reading the previous 800 posts. It doesn't appear to fulfill it's promises.

Incidentally one of the posts said that the Actis factory wasn't insulated with their own product.

http://www.greenbuildingforum.co.uk/forum114/comments.php?DiscussionID=125&page=27

Stay warm

W

[Théière]

As with any forum some of the posts are red herrings and some assume quite wrongly that all multifoils are the same which they are not. The spec for Actis Triso 10 is still not enough on it's own to meet the current spec for France or the UK so it needs to be backed up by another product and that situation will get worse as we head toward the 2020 spec of 400mm of insulation (rockwool or glass fibre) required to meet the lower Co2 emissions. I think we'll all end up with aerogels eventually.  Actis have attained a certificate

Now one of the posts says the Actis factory............Now as most people know factory's these days are built by contractors and Companies are only tenants so If someone who lives near the factory Avenue de Catalogne, 11300 Limaux, France could confirm this as I really doubt that the poster had actually visited the French factory (not that it makes much difference) The UK distributors on the other hand rent any old shed they can find and are only interested on the bottom line profit so may well not have used the product.

I will download and read the NPL report later.

[Quillan]

[quote user="Théière"]

Now one of the posts says the Actis factory............Now as most people know factory's these days are built by contractors and Companies are only tenants so If someone who lives near the factory Avenue de Catalogne, 11300 Limaux, France could confirm this as I really doubt that the poster had actually visited the French factory (not that it makes much difference) The UK distributors on the other hand rent any old shed they can find and are only interested on the bottom line profit so may well not have used the product.

[/quote]

Spot on. If we are to assume that people use the products that they make and/or sell does this mean that the workers who make Rolls Royce's or Ferarri's should all be driving around in them, of course not.

[Wilko]

The download form the link below

Conclusions 6.3

A model developed for the prediction of multi-foil system thermal behaviour indicates that the level of performance achieved even if the best possible materials were used in its construction, silver coatings with an emittance of 0.02 and foam core materials with a thermal conductivity equivalent to aerogel blankets 0.012W/mK, they do not obtain a lower U value than 200mm of mineral wool insulation.

BD2768

The download is here

http://www.communities.gov.uk/publications/planningandbuilding/multifoil

Yet Actis/Trada says:

The assessment indicates that when TRISO SUPER 10 is used as specified in the

manufacturers “Fixing Instructions” (Product Application Guide, Ref: PZ182 and

Technical Data Sheet, Ref: PZ177), the thermal insulation value is equivalent to

mineral wool (glass) of 210 mm thickness.

I guess it’s up to the reader as to what you believe but I won’t be using multifoil in any build soon.

Spot on. If we are to assume that people use the products that they make and/or sell does this mean that the workers who make Rolls Royce's or Ferarri's should all be driving around in them, of course not.

Thanks for that very valid and relevant point Quillan bit like all the people that work for NASA flying around in space shuttles.

W

[John Brown]

The largest UK DIY Warehouse Chain ( Two Letters ) withdrew the product from sale for a time because some Building Inspectors refused to agree that it achieved the performance values quoted.

We had lots of rolls of the stuff returned to the Store I was based at, by Tradesmen who had ripped it all back out because the local BI had refused to sign it off.

My understanding was that it did not conform to UK Building Regs because of its virtually total lack of sound insulation / noise reduction. ( More of an issue in the UK with flats conversions etc )

 Doubts were also expressed at successfully maintaining a suitable joint, just using foil tape and with the mountings available then

It was left, I think, with the product being sold only as a DIY product and not recommended for new build / major projects

John

[Théière]

Excluding thick builders who haven't got a clue about sound insulation, multifoils are particularly bad in that respect but have never made a claim to be good.  I have done a fair bit of swotting up, I also noticed some of the multifoils in Brico depot were made with cotton layers. Cotton as most people realise has excellent wicking properties so any damp would wick through the layers and render it completely useless. The houses that I have had to remove rock wool and glass fibre from have not been nice plumped up fibres but usually slightly compressed or slumped due to a combination of damp and natural ageing so although it maybe good insulation when fitted it is unlikely to stay that way. Also from the document below is the fact that the thickness of rock wool or glass fibre are so thick currently 240mm (France) 270mm (UK) and that would need to increase to 400mm (UK) by 2020. The only wool type insulation that can actually perform wet is sheeps wool.

That leaves us with PIR foam or polystyrene in either form although apparently Styrofoam (Dow corning) out performs both and these can be used in reasonable thickness.

The hotbox test that multifoils have so much trouble with is pretty universally tested throughout Europe and the Germans so far haven't licenced any multifoils.  However the document is now a bit old and things have moved on a pace and other than Actis there are others who recon they really are as good as 200+ mm of rockwool and 1 of those has passed the hotbox test and is licenced.

Interesting report (2007) Here

Interesting comparison of Multifoils Here

Product which HAS passed hot box test Here

 

[Quillan]

What about French products, you info seems to be about only English products.

[woolybanana]

My builder reckons to install a sheeps wool based product nowadays. He says it is well made, certified and easy to lay. I'll get the full description from him when I go past his office.

 

[just john]

Baaa, eco friendly[:D], but expensive, [Www] even with oil prices as they are, foam is more economic,
what's the roof like?, if its at all dodgey I can thoroughly recommend this http://www.laydex.com/documents/TechnicalDetails.pdf 

Usual disclaimer

[woolybanana]

Roof is excellent. This is for an inside job. See the first post in the thread.

[just john]

B&Q=sheeps_wool 1 cu metre £77

  -Celotex-laminated foam 1 cu metre £63.75

Despite having used Thinsulex on a friends property because it had been recommended by an architect and was extremely easy to install, thin and light. We stapled it to rafters, battened and fixed foil backed plasterboarded over this (within about 30mm total); and despite quoted test results it has been extremely effective in the roof bedroom conversion of his property, no damp or drafts and much much warmer. For my own property whilst examining the alternatives I found it to be too expensive and considered alternatives. Sheeps wool was considered to be eco friendly but expensive by my architect and builder,  Celotex  was recommended (there are several other makes), it comes in a variety of thicknesses 12mm to 200mm including plasterboard thermal laminate, is laminated for strength and moisture avoidance, best of all it is easy to work with, cut with stanley blade or ordinary saw to size, light to handle and fix. Without photos it is difficult envisage your exact application, however recommendations are to fill space between rafters with cut pieces and then over board the rafters. Further reading  .greenbuildingforum.. In the event my roof was so modified for renovation that despite its good condition I decided to completely remove it and use a product similar to .laydex. the results were so impressive (minimal time to fit and insulation results) that the builder and supplier now use and recommend the system.

usual disclaimers etc.

[woolybanana]

My ceiling has quite nice wooden beams with not very nice, cheap lambris between. There is some insulation above the lambris. I wanna cover the lambris with solid ceiling panels as well as adding some more insulation which will reduce the drafts and improve heat retention. This means losing some of the depth of the wooden beams, which is ok. So I figured some sort of wood or metal frame screwed through the lambris into the roof struts above, with a sheet of stapled insulating wool/celotex/ whatever, followed by the placos also screwed right through.