Attic conversion insulation - AluThermo??

run_Forrest_run

Hi All,
We are currently in the middle of having our attic converted. It is quite a large space up there (500sq ft approx) so we have a contractor in doing it for us.

In relation to insulation the guy mentioned a new type of insulation product out there called 'AluThermo'. Info here and PDF spec here.

Has anyone had any experience with this product and is it pretty good, the contractor tells us it's the latest and greatest in terms of insulation. Is he right?

sunnysoutheast

These have cropped up before - I think the major problem is that they don't have an IAB/BBA cert. so you can have issues meeting building regs.

Did I get in before Sid? Surely not

SSE

run_Forrest_run

sunnysoutheast wrote: »

These have cropped up before - I think the major problem is that they don't have an IAB/BBA cert. so you can have issues meeting building regs.

Did I get in before Sid? Surely not

SSE

ah ****e! Now you have me all worried! Typical of the contractor not to mention anything in relation to building regs :mad:

I emailed SEI about it and got the following reply:


"Aluthermo have four different products that he could be referring to: Aluthermo (7mm), Aluthermo (14mm), Aluthermo (21mm) and Aluthermo Quattro. They can be found at the following link:
http://www.aluthermo.be/en/product/description.php

I have checked out the thermal properties of all four insulators. The Aluthermo Quattro provides the best level of insulation. It has a U-value of 0.175 W/m2K.

The Aluthermo 7mm, 14mm and 21mm insulations give u-values of 0.378 W/m2K, 0.263 W/m2K and 0.205 W/m2K respectively.

The u-value is a measure of heat loss so the lower it is, the better the level of insulation.

As a point of note, Insulation products are typically tested using the standard 'Hot Box' test in accordance with European standards. However, most foil insulation manufacturers however feel that the 'Hot Box' test does not fully reflect the special characteristics of their products and hence that a test to current BS EN standards will understate the actual insulation performance that can be achieved in real installations. They have therefore sought to develop a new test method, i.e. in-situ testing, that involves calculating performance when in place. These tests are set up to demonstrate the comparative energy consumption between two buildings - one insulated with multifoil insulation and the other with an insulation that has been evaluated using the 'Hot Box' test. That said, there are no currently accepted National or European standards for performing tests in this way, and it is therefore not possible to be sure that these tests give a fair comparison of performance between the multifoil and existing insulation products which have been tested to established standards. In assessing the merits of any multifoil insulation, you should look for some evidence of independent testing. The only advice I can give is to try and check for certification from a body of some repute. If you see accreditation or certification from the British Board of Agrement (BBA), UKAS or BM Trada then the product is more likely to have the insulation values the manufacturers are claiming it achieves."

hmm, now I'm worried as they have started fitting this stuff!

run_Forrest_run

further reply from someone from SEI:

The fact that a material doesn't have certification doesn't invalidate it. Many houses are using different types of multifoil insulations at the minute.

The Building Regulations set minimum requirements for attic insulation where the insulation is on the pitch of the roof. The insulation at this level should achieve a u-value of 0.20 W/m2K or lower. The Aluthermo Quattro is lower at 0.175 W/m2K and that's not even taking the other structural elements of the roof into account.

On a slightly different note, if a Building Energy Rating Assessor came to rate the house, they would take the most appropriate u-value for the insulation material in calculating the energy efficiency and in this case they would go with the independently assessed value for the Aluthermo.

baldieman

Hi, these are excellent new insulations, but its very important that its installed properly. You must leave an air gap each side of about 20 - 25mm and all joints most be sealed effectively. I'd suggest you get a broacher on the product and how its installed and keep an eye on the work.

run_Forrest_run

thanks for that baldieman, will do.

anybody home?

Don't just take a manufacturers word for it. Especically one that isn't even certifing its products!

Have any of you even read the 'independant' data on the performance of this bubble wrap? Its on the Aluthermo website, you should if you've not, its the most appauling attempt at using physics to deceive.

Basically they have paid someone to play around with numbers until you are too confused to even bother reading what it actually says. It takes the emissivity of the outer foil layers of Aluthermo, and works out the thermal performance they would off if heat transfer was only via radiation. In other words, unless you happen to live in space where you at least have some chance of using an infinite vacuum on either side of this product, it means absolutely zip, not an ounce of practical info in there.

And as for in-situ testing, who linked Aluthermo to in-situ testing? Alot of these manufacturers have used this method to test their products, all of the uncertified ones at Sheffield Hallam Uni (they should know better). But if you delve into the google search on Aluthermo, you come up with the Aluthermo in-situ report from Sheffield Hallam, it shows that even using this flawed test method, they didn't even get a u-value of 0.20!! HA HA, thats why they must have paid this probably very clever dude to confuse the underlying message of their performance report with physics.

Sorry if you have installed this, but a u-value of 0.175, your roof is not!

davgtrek

I came across this insulation a few years ago. again no aggregment certs etc but the figures were excellent. However space age it is for it to achieve anything near its values it requires air space on both sides.
This is almost impossible to achieve in an attic scenario. Not worth the trouble TBH. Stick with xtratherm yellow insulation boards and you will be fine. Increase the thicknesses the builder may suggest to at least 300 mm quilt insulation on the horizontal ceiling.
If u have any sloped ceiling then make sure at least 100mm xtratherm yellow insulation between rafters ( remember 50mm air gap to felt ) and use laminated ( insulated ) plasterboards with at least 25mm insulation then fixed to rafter underside.

good luck

P

anronmor

Hi All,
seems like an air gap is pretty much essential to get some good insulation from this.

I was thinking of using this for a camper van conversion as it would be pretty good in terms of water resistance - I've heard that fibreglass rolls just sponge water and go to crap.

any thoughts on if aluthermo is suitable for lining a camper?

I'm thinking attaching it to the walls and roof of the van with contact adhesive and then putting a layer of upholstery / carpet on top

ccwaterford

I also read the independent data on the website and it is less than inspiring. Was looking at using this material myself however still no IAB or BBA certificates or reputable independent reports. Should I stay away from this product? Any updates?

anybody home? wrote: »

ccwaterford

dathi

ah lads a bit of cop on please they have no IAG certs why do you think kingspan/xtherm have put foam between the two layers of aluminium on there product for years? perhaps to improve its thermal resistance? oh and if someone can show me a detail where it can be installed leaving an air gap with out compressing it with plasterboard on joist/rafters i will bow to them rant over now

siocs

Just wondering how RunForestRun got on with the insultion. I have builders doing just the structural work of attic conversion for me. Will do the insulation at later date, but the builders trying to convince me that alutherm the way to go. ifI did use it, I would put it on rafter, batten over (2x1) and then use a plasterboard slab just to be sure to b sure.

siocs

Insulation (not insultion)
And an insulated plasterboard slab as well (not just normal slab)

Patricevdw

I'm doing a similar thing with my old barn and wondered what the current thinking is.

RunForestRun, what are your results?

Siocs, did you ever do this and ditto on the query, good results?

paddy147

Did this a while ago.
100mm Rockwool slab installed.

Then Knauf Carbon Zero 170mm insulation installed over that.

Great sound reduction and snug as a bug in a rug.:D

I also had the house spray foamed with Bio-Foam Open Cell 800