DIYbanter - View Single Post - Mineral wool or polystryene for cavity walls

wrote:

Bob Smith (UK) wrote:

I recently got a flyer through the letterbox from a company wanting to take
advantage of grants to insulate private homes. They say they will insulate
my house with mineral wool for £150, and that it is £400 without the grant.

Is it any better than polystyrene? Does mineral wool conduct damp, ie, does
mineral wool "bridge" damp proof courses. I know polystyrene does not
conduct damp. Also, what would be the cost difference?

Thanks

Bob

polystyrene can cause damp problems, it saturates with water.

Eh? Polystyrene impervious to water.

Rockwool is also, but being fibrous, can soak it up like a sponge.

Also it
contains plsticisers. And when it contacts pvc cables (only in houses
where pvc cable is in the cavity) the cable turns to goo.

NT