Foil v Blanket insulation

[bboy]

Could anyone tell me the pros/cons of using foil-based insulation over standard blanket insulation.

I've been happy with using something like Knauf spaceblanket before but would like to know if the thinner foil-based stuff is as effective (something like Airtec from Screwfix).

I'm not going to board the loft or anything like that so size isn't really an issue - which is the more efficient, or have I got things seriously mixed up?

Thanks in advance.

[Nev]

Hi bboy,

The Spaceblanket stuff is on a buy-one-get-one-free deal at B&Q at the moment (£14 for 2 rolls.) I'd assume the benefits of lesser volume insulation compared to the increased cost of it would mean that the Spaceblanket stuff is a better option.

[bboy]

Thanks Nev, still might go with the Knauf Spaceblanket stuff, and if it's on special, even better.

To sort this out in my head though, could I just use a foil-based insulation on it's own (with no glass fibre in the product) or is it no good for lofts?

Thanks again,

[freddymercurystwin]

The thing with insulation is that every different type has a different thermal conductivity, that's its ability to conduct heat. The lower the figure quoted the better, for example Rockwool Cavity insulation is 0.037Wm/k. But it also depends on the thickness, more is better obviously. Generally the thinner foil 'layered' types are used where space is an issue i.e. headroom in a loft conversion. Just beacause an insulation is cheaper it doesn't mean its going to keep more heat in and vice versa.

[sthelenslad9]

some insulation is used on timber frame houses.
and not suitable for bog standard loft insulation.
ie:140mm frame therm external walls.
ie:90mm frame therm party walls
all different u values all expensive.
use stuff from b&q cant go wrong