In message , Phil L
writes
Rockwool is cheaper
and easy to cut and fit but... how do you stop it ending up resting on
the ceiling plaster board, light fittings and electrical wiring?

Chicken wire netting? Some sort of cross batten or?? My floor joists
are 9" deep and Rockwool 6". Perhaps lengths of plain galvanised
fencing wire stapled between the joists? Any impact on wi-fi
transmission?

Insulation isn't needed for upstairs floors, any heat 'lost' isn't actually
lost - it's just transferred downstairs into the living space which will
reduce the amount of power required to heat that space.

You are right of course but I think this is more to do with heat
management in local zones. Not much point in having individual roomstats
if the whole house is thermally linked.




--
Tim Lamb