Multifoil Insulation

[Nick Grant]

John Willoughby just sent me this;

http://www.celotex.co.uk/pdf/Multi-foil_Bulletin.pdf

Celotex has commissioned the NPL to test Tri-Iso-Super 9 Multifoil insulation and the results confirm what the AECB Energy experts have been saying for some time now but didnt have the resources to prove.

[David Olivier]

Canada's CHMC commissioned Enermodal Engineering to look at a different multi-foil; similarly dismal results (for the materials' promoters).

The authorities in USA even the FTC have been advising caution for years. These materials can have benefits in cooling climates (hot) but may be far less effective in heating (cool or cold) climates.

Somewhat bizarrely, this material has gained “official” UK approval, with the result that Bldg Inspectors have to allow its use whether or not they like it. Whether it keeps its approval may be doubtful.

[Anonymous]

Dont be put off by all the sceptics.
I have dry lined parts of my house with tri-iso.

It is very effective for refurbishment and conversion work because it uses so little space.

There are those that say it does'nt work.

All I can say is that I have drylined a room in my house with 3 external 9″ solid walls.
The room was unheatable and now with a layer of tri-iso it is easily heated with a small radiator.

[Peter Warm]

;D Shame you needed the radiator, think about what it would have been like if you used real insulation!

[Anonymous]

;D

Do you mean warmcell which settles over time and does'nt like damp conditions!! It is very easy to find fault with any insulation because there is no perfect solution.

I think its horses for  courses and different products are the best for different situations.

Its a shame that there is so much scepticism about a product that serves as very useful option in many situations.

There is a very interesting discussion on this subject on the newbuilder forum which offers much more considered views on the subject than seems to be the case here.

[Jonathan Sear]

My partner  and  I have decided not to  use tri-iso super 9.  Our problem is  that using rockwool will lower the  ceiling height by at least 110mm (if we go for  minimum insulation).   This will reduce head space at the top of the landing and above the shower in the bathroom, for example.  Do members have any alternative  suggestions that involve preserving ceiling height and maximising  U-values?  There is nothing  but the rafters, a ventilation gap, and slate where the slopping ceilings are.  This affects the external walls in all upstairs rooms.

[Nick Grant]

Going back to Nigel's post everyone agrees with the concept of 'horses for courses', the issue with the multifoil insulations is that they could well be donkeys.

Some of the people with the 'unconsidered views' on this thread have been considering insulation and building details for a condiderable time and in considerable depth all over the World so your comment both amused and annoyed me.

What is being debated is whether the multifoils achieve the U values they claim.

This is not a matter for opinion, testimonial or anecdote.

If they do work as claimed then I will be very pleased as low energy buildings will suddenly be so much simpler to build and retrofit will be a cinch. The scientific (as opposed to anecdotal) proof would by its nature allow these products to be optimised and made even better, imagine 100mm of the stuff!

Indeed this is an issue, people want these products to work as the alternatives are more hassle.

If they don't work (my money is on the horses) then this needs to be flagged up as a matter of urgency.

Part of having an open mind is being open to the posibility that some things are simply b*****s.

[Nick Grant]

The story goes on.

BRE have produced a report that looks at Tri Iso Super 9 in buildings that gets results that supports the sceptics.

http://www.planningportal.gov.uk/PpWeb/jsp/redirect.jsp?url=http%3A//www.planningportal.gov.uk/uploads/br/multi-foil-insulation_july2005.pdf

[David Olivier]

Earlier in the thread, Nigel implied “it must be effective because my room is now warm” but this is unreliable. In an old building, almost any added insulation makes a huge difference because the original wall is so poor at keeping the heat in.

If Tri-Iso was added to a 215 mm solid wall, and if it performs as well as 40 mm rockwool (as the tests are now suggesting), the wall U-value might drop from 2.1 to about 0.67 W/m2K. Given this 70% drop in heat loss, I'm not surprised you noticed a big difference, but it's well short of the U-value of <0.25 W/m2K which you'd get with say 100 mm PU foam.

David.

[Anonymous]

The debate on multifoil insulation continues please see the article on the following website:

http://www.ovolopublishing.co.uk/housebuildersupdate/2006/10/multifoils-banned.html

Peter

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