External Insulation of Timber Frame

[biffvernon]

Part of the trouble stems from disagreement over what is a proper test. The multifoil manufacturers claim that the hotbox test conducted by the NPL and others does not adequately reflect the real world conditions with dynamic changes in heat flows and does not properly account for the radiative effect. They say look at real houses - it works. But this is muddied by varying standards of workmanship and the airtightness issue.

My own view is that the theoretical physics says it shouldn't work. Some people say I'm wrong.

As I said, fro the humble builders' and BCO's view, one has to read the smallprint on the BBA certificate very carefully.

 

[Flyfisher]

They say look at real houses - it works.

Which is what Jon appears to be saying as well.

 

[biffvernon]

He is saying it, but that does not mean that the internal layers of foil are contributing anything very useful.

 

[Flyfisher]

Agreed, but is it relevant?

If I sell a triple-glazed window for £500 with a U-value of X, I can't really see how someone can later object on the grounds that they could have bought a double-glazed window with the same U-value for less money. The window has delivered the performance that was specified. Buyer's choice.

Now, if the material in question does not deliver the quoted performance then fair enough, there is a case to be had. But if it does perform as per specification (and Jon has already stated it is working very well indeed) then, regardless of the efficiency and cost of it's construction, what is the problem?

It may well be that the science has moved on in 4-5 years and there is now a better understanding of the technology, the physics or whatever, but I would be very wary of taking legal action on that basis. At the very least I can imagine teams of highly paid lawyers and barristers having a field day arguing over the implications of inevitable technological progress at £1000's per day. Very nice work indeed, m'lud. And for what?

 

[biffvernon]

I don't think the science has moved on at all. I don't think much science has been applied to the problem. The scientists at the National Physical Laboratory have tested the stuff and given their opinion. A lot of folk have ignored them or said that they didn't do the right right science.

Remember, I'm not really saying anything beyond pointing out that the internal foils add little to the thermal resistance and so are not good value for money. Other folk can draw their own conclusions from that fact.

 

[Flyfisher]

Surely the science has moved on to the extent that it is now thought that the inner foils contribute little to the overall performance?

Either way, I entirely agree that the issue seems to boil down to value for money, and that's why I seriously doubt there is any case to answer and why only lawyers would benefit from pursuing it.

 

[biffvernon]

Here is a multifoil BBA certificate: http://www.bbacerts.co.uk/certs/45/4543i1_web.pdf

Here is some of what it says:

Thermal performance — when combined with other types of insulation, the product can contribute in meeting the
U value requirement for a roof

Got that? "when combined with other types of insulation".

and further on:

5.1 The ultimate thermal performance of the product will depend on the construction of the roof on which it is
installed and the combination of it with other insulation products is necessary to achieve the following design
U values:

There it is again: "and the combination of it with other insulation products is necessary".

This certificate has as many holes in it as cavity walled, dab and dobbed, Wendyhouse.

 

[Jon Maine]

Here is a multifoil BBA certificate: http://www.bbacerts.co.uk/certs/45/4543i1_web.pdf

Here is some of what it says:

Thermal performance — when combined with other types of insulation, the product can contribute in meeting the
U value requirement for a roof

Got that? "when combined with other types of insulation".

and further on:

5.1 The ultimate thermal performance of the product will depend on the construction of the roof on which it is
installed and the combination of it with other insulation products is necessary to achieve the following design
U values:

There it is again: "and the combination of it with other insulation products is necessary".

yes but that certificate is 2008, I installed mine in winter 2004/2005 after alleged claims it complied to current building regs at that point in time.

This certificate has as many holes in it as cavity walled, dab and dobbed, Wendyhouse.

What claims were made in 2004, those bba certs are from 2008

 

[Flyfisher]

Fair enough Biff but, again, what's the relevance? You say that the inner foil layers are not contributing to the performance and only adds to the cost. OK, so it might be an inefficient construction in the sense of having more layers than absolutely necessary, but that's no basis for legal action. There must be millions of products out there that could be manufactured more efficiently. Surely the only relevant question is 'does it do what it claims to do', not whether it could do it with a different construction.

I can buy a gold-plated mains plug for my hi-fi system for £60. I can fit it with a rhodium-plated fuse costing £40. I can wire it up with cable costing £15/m.

The bottom line is that Jon's roof is (apparently) performing well and my hi-fi would still work (I assume) if I bought the above items. Both may be overkill for the purposes in hand but that's hardly a basis for legal action.

 

[biffvernon]

I'm not calling for legal action. Just pointing out what I've learnt. Jon, I don't think there was a BBA certificate in force in 2004 - you'll need to check that. If I recall correctly, there was a time when Actis Tri-iso9 was advertised with a wording which the ASA eventually ruled inadmissable. Actis changed the advertising and replase Tri-iso 9 with 10.

One problem, Fly, with Jon's roof is that although he thinks it is performing well he has not been able to measure the thermal resistance of the roof. Technically, that's a very difficult thing to do outside a laboratory. His house may be warm, but perhaps it would be just as warm had he used a different material and used less fuel. That's an issue of enormous importance when we multiply Jon's roof over a million houses.

 

[Flyfisher]

Jon was questioning the legalities. I think we're basically saying the same thing about the product. I don't see what can be done about 'value-for-money' for any product - isn't that a consumer choice issue?

 

[Jon Maine]

Jon was questioning the legalities. I think we're basically saying the same thing about the product. I don't see what can be done about 'value-for-money' for any product - isn't that a consumer choice issue?

Really what I am asking are these points.

1/ Whilst I no longer have the sales literature when purchase in 2004 ( I used frame foil not Actis ) claims were made about its performance which convinced me and the building control department to install it by itself and it would comply with the then regulations.

2/Within a year or so these facts and figures have been seriously questioned and the ASA have jumped on sales pitches as potentially mis leading apparently. So have I been mis sold?

3/ The material is no longer accepted as being suitable for use by itself and certain manufacturers as I understand it have re-introduced lower performance values which appear to contradict the original claims. Am I correct in this assumption?

Yes I agree my insulation works, I am just trying to assess if my insulation does not work as well as it was claimed to when I bought it. If that is the case and I can structure a reasoned factual argument establishing that I am wondering if I should take legal action to rectify the situation.