Ceiling replacement advice please

[macxdiy]

Complete newbie to DIY and new member to this forum although I've had a browse from time to time!

1965'ish - 2 bed terrace...

I plan to remove and replace my entire living room ceiling, including entrance porch. Living room ceiling approx 3.6m x 5, porch 1m x 1.5m

I need to rewire for new lighting, electrics (for this room and others) and audio visual, plus I need some better sound proofing between floors. The existing ceiling shows signs of water damage too.

I'm pretty sure the old artex coating is made up of crysotile, as I had it tested when I bought the property many years ago.

I'm not sure whether to order 12.5mm or 15mm sound proof plaster board nor am I sure where I will get the best deal! Having looked around I see the size of a sheet is mostly 1200 x 2400. I was also thinking of fixing some firecheck to the underside of the floor boards above to provide a little extra soundproofing and the peace of mind of firecheck. Ripping up the floor upstairs is not an option.

I'll be making holes in the joists for new wiring etc but the actual electrics will be carried out by a qualified electrician.

I have a friend to help with general labour.

Then finally a plasterer will be skimming the ceiling. I'll probably get the electrician back at that point to put the lights in.

Any advice much appreciated - feel free to tell me if I'm undertaking something that might be a little too much to handle!

 

[Micilin]

I don't think there's anything there you won't be able to do, espcially if youhave a mate to help with the boards (firelined and sound boards are heavy) and are getting a plasterer to skim it.

I'm not sure about the merits of firelined board to underside of floorboards - do you mean between joists?

 

[macxdiy]

Thanks for your confidence in me Micilin! I really hope I'm not going to get myself in a right mess and stand back wishing I'd never started! I'm actually starting this today.

Yes the fireboard would be up between the joists, I have quite a bit spare from a previous project that a tradesman did - it's been sitting in my garage doing nothing so I thought the added benefit of some extra density for sound proofing and a firesafe'ish backing for the down lighters will help give me peace of mind I suppose. I was thinking to hold up each section with a couple of screws and mostly 'no more nails' as I don't want to give the floor upstairs any more reasons to creek!

 

[Peet]

For sound proofing, mass counts. In my experience a modern 12.5mm plasterboard ceiling is inferior sound wise to an old 40s lathe and plaster ceiling it replaced. Soundproofing boards are usually physically quite heavy. Fireline is too. And also comes in 15mm from memory. Other factors like the void size between joists effect the sound transmission too, the biiger the void the worse the low frequency sound transmission is. But if the sound is noise directly coupled into the fabric of the building, like a chair scraping across the floor upstairs, then it is very hard indeed to stop it travelling. The most effective remedy is to stop it in the first place, in that case by carpetting the floor upstairs.

Using small plasterboard off-cuts is counter-productive as you end up having to tape them all before plastering. Plus to achieve fire integrity the joints have to be staggered. If you want serious sound proofing and fire integrity then how about double firelining it? If you're puncturing the ceiling with downlighters then these will be the main problems to sound transmission and reduced fire resistance. You'd need to investigate their fire ratings.

For plasterboarding technique look at the Zurich insurance site for their recommendations on achieving fire lining. No nails involved, a screw at least every 150mm, staggered joints, taped and 2 skims of plaster. And if it was me PVA the boards before plastering as it does effect the bond.

What were you going to hold up with 'no more nearly no nails'?