New ceiling what insulation to use

[wood1e2]

hi

I had to pull down part of out kitchen ceiling due to water damage, I have fixed the water leak issue, and ready to put up new ceiling.

In the void/between the joist was earthwool insulation, just rammed in there no matter what pipes or electricty cables there are, would repeating this be a problem?

And if it is not a problem could i use a Rockwall slab? As i hate the floppy insulation.

What I want to do is get the best insulation with the best noise reduction, as kitchen is immediately below the bathroom. At the same time I don't want to burn the house down with insullation rammed in aganist electricity cables

I've a attached a couple of pictures,

 

[Wayners]

Rock wool insulation and foil backed plasterboard as its a kitchen.
Wear eye goggles and gloves.
Horrible job to do from below.

As for sound blocking nothing will improve it. Adding insulation of any type won't do anything unfortunately.
You would need resilient bars ect to block sound.
People think I'll try and muffle sound or lower it a bit, but that won't work. It's all or nothing

 

[JohnD]

What is above it? A flat roof? A loft? A heated room?

The one thing I would absolutely avoid is old-style yellow glass fibre, which sheds irritant dust and fibres. Clean and hoover it out wearing a mask and goggles. Modern mineral wool treated with Ecose (it will be branded on the wrapper) does not shed irritant fibres and is very preferable.

As for electrical cables, they must not be buried in insulation, but on at least one side they must be exposed to the air or fastened to an uninsulated surface such as a wall or roof so that heat can escape.

The only exception is lighting circuits, because the load (especially with modern LED energy-saving lamps) is so low.

It is possible to calculate loadings for cables buried in insulation, but not worth the trouble.

Edit
I see the bathroom is above.

No need for heat insulation as it is a heated room.

And avoid fibrous insulation as it will hold water when there is a leak or overflow.

For noise, use a double layer of plasterboard, plus plaster skim, and take great care to seal all holes and gaps around joints, pipes and cables. Do not make great holes in it for downlighters. You can use pink fire foam round the edges. Foil backed plasterboard has some resistance to steam and damp.

 

[foxhole]

I found slab insulation very good at sound insulation , used it in an office between two meeting rooms so one meeting could not be heard from the other .

 

[foxhole]

What is above it? A flat roof? A loft? A heated room?

The one thing I would absolutely avoid is old-style yellow glass fibre, which sheds irritant dust and fibres. Clean and hoover it out wearing a mask and goggles. Modern mineral wool treated with Ecose (it will be branded on the wrapper) does not shed irritant fibres and is very preferable.

As for electrical cables, they must not be buried in insulation, but on at least one side they must be exposed to the air or fastened to an uninsulated surface such as a wall or roof so that heat can escape.

The only exception is lighting circuits, because the load (especially with modern LED energy-saving lamps) is so low.

It is possible to calculate loadings for cables buried in insulation, but not worth the trouble.

Edit
I see the bathroom is above.

No need for heat insulation as it is a heated room.

And avoid fibrous insulation as it will hold water when there is a leak or overflow.

For noise, use a double layer of plasterboard, plus plaster skim, and take great care to seal all holes and gaps around joints, pipes and cables. Do not make great holes in it for downlighters. You can use pink fire foam round the edges. Foil backed plasterboard has some resistance to steam and damp.

Op mentions below bathroom ( and water damaged).

 

[aveatry]

I did my kitchen ceiling last year same as you with bathroom above and I used 75mm rockwool slabs cut to a snug fit and they stay in place while you board it but I did have to pop in a few long screws here and there where the slabs were not so snug. Those rough cut joists hold them in place pretty well. I cut the slabs with an old electric knife - works a treat.