On Wed, 30 Mar 2005 10:14:45 +0100, "Doctor Evil"
wrote:



Old wives tales.

A surveyor advised me this having seen many rotten roofs apparently.

It is normal practice to cover the joists to eliminate
cold bridging.

In modern houses with foil backed plasterboard ceilings - no problem

The loft will be vented so that air movement will take away
water vapour.


But the rockwool prevents air circulating around where teh
condensation is. The condensation happens within the rockwool and
joists.