Bob Mannix wrote:

that's not the main point) they go over the old and under the new. Fire (and
noise) requirements will be met by laying mineral fibre (rockwool or
similar, not glass fibre) insulation between the joists (80mm plus), nailed

You can actually use glass fibre - it has the same grade A fire rating.
(our BCO wanted it laid on chicken wire which was fixed to the joists)

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/