Posted By: ratminIt looks as though it could be a scam.

I've no experience of it, but with a description that includes

It is applied 1mm thick to create a thermal insulation barrier

and

reduces a similar amount of heat loss to 100mm of internal or external wall insulation

I can see why you might be suspicious!

Hmm, reflective insulation that is a paste trowelled onto the wall and that can be covered by wallpaper. How does that work then? The safety data sheet is suitably vague about pretty much all its properties.

Some tech data..

http://www.aerotherminsulation.co.uk/technical-test-information/

•Thermal conductivity (EN 12667): 0.047 W/mK
•Emissivity, spherical emissivity at 20C (Taylor method): 0.93

Presumably the latter is unpainted.

They also cite a before and after test data here..

http://www.aerotherminsulation.co.uk/wp-content/uploads/2014/07/Origin_Test.png

They claim a 36% energy saving but I noticed they say "After Aero-Therm was applied the same comfort level was achieved at 18C" where as the before test was carried out at 20C.

Energy loss is proportional to temperature gradient. The gradient "before" was 20-11C and "after" it was 18-11C.

The ratio (18-11)/(20-11) is about 0.8 so quite a lot of the saving appears to be down to the claim that "After Aero-Therm was applied the same comfort level was achieved at 18C".

What happens in summer? Does it make 30C feel like 32C ?

http://www.chroda-eco.co.uk/method-statement.html
another one here, slightly different, sure they work a bit on uninsulated walls and you ould say better than just putting on new render or plasterer if no other upgrade is being done.

good rule , never seen it enforced or mentioned all the time they've had it , I deal with BC control regularly

good idea but meaningless if not enforced. had 2 decades of empty window dressing from our government bodies on building quality etc. the only improvement and forward movement comes from individuals or private companies leading the way by their own choice. shame on HMGOV

Posted By: jamesingramshame on HMGOV

Absolutely.

''Other upgrades might be mandatory to meet Building Regs..

http://www.planningportal.gov.uk/permission/commonprojects/externalwalls/

"Where 25 per cent or more of an external wall is re-rendered, re-clad, re-plastered or re-lined internally or where 25 per cent or more of the external leaf of a wall is rebuilt, the regulations would normally apply and the thermal insulation would normally have to be improved [If they don't already meet the regs]" ''

jamesingram 23 hours ago quote
good rule , never seen it enforced or mentioned all the time they've had it , I deal with BC control regularly

**I have in Sheffield, and I advise my clients accordingly.

And that quote on PP is out of date. See s. 5.8 of approved doc L1B (2011), which shows that, for IWI, for example, the cut-off will normally be 50% **in the room you are stood in**.

Hard vacuum insulants (e.g. evacuated glazing) are the best insulation known to man, at least in one direction.

But that's probably irrelevant.

This sounds awfully like advertising to me which is not allowed on this forum.

bumping up an old thread to plant your advert is not on !!!

As an example application, we have cavity wall insulation, and the plaster in our bedroom on the outside wall is “live”. There are lots of cold bridge etc around windows etc.

If an insulated plaster cost little more than normal plaster (including the cost of the plaster) and the job can be complete in a day, then it will be very tempting when we come to decorate that room. (However the insulating plaster must be on sale local to me at a good price with the option to take back any bugs not used.)

Posted By: ringiAs an example application, we have cavity wall insulation, and the plaster in our bedroom on the outside wall is “live”. There are lots of cold bridge etc around windows etc.

If an insulated plaster cost little more than normal plaster (including the cost of the plaster) and the job can be complete in a day, then it will be very tempting when we come to decorate that room. (However the insulating plaster must be on sale local to me at a good price with the option to take back any bugs not used.)

Thought I would do some sums to work out roughly how much the insulated plaster would add to the thermal resistance of a cavity wall compared to no plaster at all.

Your cavity wall might be better insulated than this but that would make the effect of the plaster even less..

I assumed..

Outside
100mm brick
50mm air
100mm Celotex
100mm Standard blocks
Inside

The Celotex calculator gives that a U-Value of 0.16 W/m^2.K which is a Thermal Resistance of 6.25 m^2.K/W

"Bauwer Light offers true thermal performance at 0.068 W/m*K"

So a 10mm thick layer would have:

u-value of about 0.068 * 1000/10 = 6.8W/m^2.K
or
Thermal Resistance of 0.14 m^2.K/W

So the total Thermal resistance with 10mm of the Bauwer plaster would be..

6.25 + 0.14 = 6.39 m^2.K/W

That's an improvement of..

100*(6.39-6.25)/6.25 = 2.2%

compared to no plaster at all.

Perhaps someone could check these figures.

>As an example application, we have cavity wall insulation, and the plaster in our bedroom on the outside wall is > “live”. There are lots of cold bridge etc around windows etc.

>If an insulated plaster cost little more than normal plaster (including the cost of the plaster) and the job can be >complete in a day, then it will be very tempting when we come to decorate that room. (However the insulating >plaster must be on sale local to me at a good price with the option to take back any bugs not used.)

>Thought I would do some sums to work out roughly how much the insulated plaster would add to the thermal >resistance of a cavity wall compared to no plaster at all.
>Your cavity wall might be better insulated than this but that would make the effect of the plaster even less..
>I assumed..
>Outside
>100mm brick
>50mm air
>100mm Celotex
>100mm Standard blocks
>Inside
>The Celotex calculator gives that a U-Value of 0.16 W/m^2.K which is a Thermal Resistance of 6.25 m^2.K/W
>"Bauwer Light offers true thermal performance at 0.068 W/m*K"
>So a 10mm thick layer would have:
>u-value of about 0.068 * 1000/10 = 6.8W/m^2.K
>or
>Thermal Resistance of 0.14 m^2.K/W
>So the total Thermal resistance with 10mm of the Bauwer plaster would be..
>6.25 + 0.14 = 6.39 m^2.K/W
>That's an improvement of…100*(6.39-6.25)/6.25 = 2.2%
>compared to no plaster at all.
>Perhaps someone could check these figures.

Hello,
Thanks for your comments; I checked these figures....and all the numbers you shared are exactly correct :)
Saying that, your assumptions are not reasonable in my view….let me explain why:

It is like checking the effect of weight loss pills on a very fit person…the effect would be less than 2% of the weight reduction as person is already fit, low weight, so no need for pills in this case :)

You start in your comparison with a great declared U value of 0.16 W/m^2 (no extra insulation is really needed in this case :) and by applying Bauwer Insulated Plaster at only 10mm thickness (too thin really) you improve U value only to 0.14 m^2.K/W

The situation is different when you start with 225mm solid brick wall with U value of 2.75 W/m^2.K which is a typical solid wall building, many millions of those buildings in the UK.

Application of only 10mm Bauwer Insulated Plaster (10mm too thin and therefore not recommended) would improve U value to 1.96 still about 30% improvement vs base line.

Application of 50mm of Bauwer would deliver total U value of 0.91, 67% improvement
Application of 100mm of Bauwer would deliver total U value of 0.55, 80% improvement vs original U value of 2.75

Now let’s assume more modern unfilled cavity wall with U value of 0.60 W/m^2.K; application of 100mm of Bauwer would deliver total U value of 0.32 or about 50% improvement from original 0.60

Hope this helps.

Other consideration:
Insulation board would potentially have “cold bridges” on connections of each board, so the actual U value might be different from the one declared or calculated above, as those “cold bridges” are not taken into consideration. Potentially losses could up to 40%, particularly if installation job is not done correctly. No “cold bridges” with Bauwer Insulated Plaster, even in the uneven areas, like windows areas, etc.

Insulation boards are not vapour permeable, so wall cannot breath, there are number of potential issues associated with that. Bauwer is more vapour permeable vs traditional plasters at it is light-weight at only 280kg/m3 of hardened density.

Due to light density, Bauwer is not only more vapour permeable, but also more cost efficient vs traditional plasters and renders if you look at £ per volume, eg. sqm coverage at particular thickness.

>If an insulated plaster cost little more than normal plaster (including the cost of the plaster) and the job can be >complete in a day, then it will be very tempting when we come to decorate that room. (However the insulating >plaster must be on sale local to me at a good price with the option to take back any bugs not used.)

Bauwer insulated plaster is cheaper vs traditional plaster and render due to Bauwer’s light weight density being just 280kg/m3 vs about 1,500kg/m3 of traditional sand and cement render. There is a greater product output volume per bag, generating considerable savings, on the top of other benefits like thermal, acoustic and fire performance.

For example one bag of Bauwer Light would covers 2.5 sqm @ 10mm thickness with a price tag of below £10 including delivery and VAT with one pallet, 104 bags being, minimal order quantity.

Posted By: Bauwerone pallet, 104 bags being, minimal order quantity.

If I can't buy it at Wicks by the bag and take back what is not used, then I would not consider using it for a single wall in one room. Also the plaster must be happy with it, otherwise he will quote more to do the job.

>Indeed, and I suppose that hard-sell tactics may be appropriate there. But this is the Green Building Forum and >recommending that people try to waive even the very limited thermal requirements of Building Requirements >doesn't seem to me in the least appropriate as a comment in a general thread.

I believe in many cases house owners decide now to progress with internal or external walls insulation systems (even with help of Green Deal), just because it is simply too expensive. So if we could achieve 80% U value improvement at 20% of cost, I would suggest it is still Eco-friendly in my humble opinion.