Insulation effectivness of these two...

[Cocat2517]

This stuff claims to be as effective at insulating as 65mm mineral wool... Airtec foil. Is it fair to assume it would be a better insulator than polystyrene boards such as these 25mm boards? It's for internal wall insulation, specifically around window reveals where space is tight.

The foil roll is also half the price per m². Both would be covered by 12.5 plasterboard.

 

[foxhole]

Much better than polystyrene, but must no be compressed .

 

[Cocat2517]

Would it lose much of its effectiveness if compressed slightly? Was thinking of attaching it via spray contact adhesive, then plasterboard over top to finish. If doing this would reduce effectiveness would doubling it up (I'll have more than enough left over) counter this?

 

[Mr Chibs]

How are you intending to fix the plasterboard to the foil?

Insulation needs to be uncompressed unless it's foam/polystyrene otherwise the insulation value is a lot lower.

 

[Cocat2517]

How are you intending to fix the plasterboard to the foil?

Insulation needs to be uncompressed unless it's foam/polystyrene otherwise the insulation value is a lot lower.

Not sure, probably 35mm nailable plugs (will screw them in rather than hammer).

Perhaps a better option is a tiny bit of adhesive at corners of the foil insulation to hold it in place, then board over with plasterboard fixed with the plugs? Would this compress it too much?

I've only got about 15-20mm depth to get something in, hence the foil stuff and not something like poly back plasterboard.

 

[SFK]

Cocat, Just incase you have not used or seen that product in real life....

It is a strong bubble wrap with a very thin metal coating.

It works okay for my applications (I use staple gun to affix). The bubbles are strong, but not sure if the bubbles will not slowly pop over a few years if continuously compressed.

SFK

 

[Mr Chibs]

How come you can only spare 15/20mm?
Wondering as if you could, perhaps insulated plasterboard would be better suited.

 

[Cocat2517]

How come you can only spare 15/20mm?
Wondering as if you could, perhaps insulated plasterboard would be better suited.

It's an old solid stone walled house, edge of the window frame meets the stone wall, the frame is about 30mm but I don't want anything coming out as far as the opening. There's 22mm insulated plasterboard, but that's 9.5mm plasterboard and only 12.5mm of polystyrene insulation, so not much.

I just need enough really to prevent risk of condensation around reveals, but would like the most effective thin layer as possible to keep as much heat in as I can too.

 

[foxhole]

Very little risk of condensation on reveals .

 

[IT Minion]

That stuff sounds too good to be true and contradictory. The thermal resistance and conductivity numbers don't add up nor does it make sense. It's bubble wrap. Not magic.

If it were that good why doesn't it get used all the time instead of rockwool? If you want to get the best performance out of the minimum depth then don't compare to polystyrene, compare to PIR.

 

[JohnD]

IIRC the installation method is to put the film on the surface of e.g. roof timbers so that there is an air gap the depth of the timbers which they include in the effective insulation.

I suspect that you could get nearly the same value (on that assumption) by putting clingfilm or wallpaper up.

The foil itself is far too thin to have much effect.