ceiling insulation up at floorboards or on the drywall?

Hi I'm rebuilding my ceiling - should the insulation rockwool be pushed up against the floorboards above or leave it at the bottom of the joists just above the resilient channel? cheers all

How about both? That would be ideal -- slight pressure on both leaves.

twice the price aint so nice!

You don't need rockwool for inside ceilings or walls; use standard fiberglass insulation and do a complete fill with slight (about 20%) compression - it'll cost closer to the same amount and do just as well. Save your rockwool for aocustic treatments. If there is heated living space ABOVE you, get UN-faced insulation batts; if it's your outer roof, get kraft paper faced, and put the facing toward the room (unless the UK has changed climates since I was there :wink: ) Steve

I have the rwa45 already, I think it was recommended on another forum for ceiling filler...