Replacing a Lathing Plaster Ceilling
Discussion
Our new flat has a lathing and plaster ceilling that is completely knackered, and also gives no sound insulation. We want to replace it with a new ceilling. In replacing the ceilling we have to pass Part E, which is hard without access to the floors above. Also, we have virtually no head room to add a suspended ceiling bellow the existing ceiling. Our proposed solution is:
Accoustic wool insulation between the joists.
Resilient bars onto the joists,
2 layers of soundblock plasterboard hanging from the Resilient bars,
further acoustic wool between the base of the joists and the PB.
This was the solution we eventually reached having spoke to architect and tech dept at Knauf and British Gypsum.
However the architect now thinks that there is an issue because the lighting cables will be above the plaster board, and therefore outwith the fire protection. He is proposing that we add a fire rated ceiling, and then another ceiling below that, with the cables in the gap between. This won't work though, because of the limited head room.
As far as I was aware, lighting cables always run above the ceillings? and I've never heard of a double ceilling being installed. I'm wondering if the architect is being paranoid, and it will be acceptable to run the cables above the PB? Alternative to his solution, I thought some form of fire proof conduit for the cables would be a better answer. Has anyone had any experience of needing to install this/recomendations on where to get some?
Thanks in advance
Graham
Accoustic wool insulation between the joists.
Resilient bars onto the joists,
2 layers of soundblock plasterboard hanging from the Resilient bars,
further acoustic wool between the base of the joists and the PB.
This was the solution we eventually reached having spoke to architect and tech dept at Knauf and British Gypsum.
However the architect now thinks that there is an issue because the lighting cables will be above the plaster board, and therefore outwith the fire protection. He is proposing that we add a fire rated ceiling, and then another ceiling below that, with the cables in the gap between. This won't work though, because of the limited head room.
As far as I was aware, lighting cables always run above the ceillings? and I've never heard of a double ceilling being installed. I'm wondering if the architect is being paranoid, and it will be acceptable to run the cables above the PB? Alternative to his solution, I thought some form of fire proof conduit for the cables would be a better answer. Has anyone had any experience of needing to install this/recomendations on where to get some?
Thanks in advance
Graham
mrmaggit said:
Is he confusing lighting cables (that's where they're supposed to go) or downlights, which need to have fire-sleeves between them and the insulation?
I did ask if he meant downlights, because I knew they either needed fire hoods, or built in intumescence(sp?). His response was that all lights(i.e downlights, pendants and batten holders) need a hood, which again I am pretty certain is wrong.How bad is the noise issue? If this is not the major problem and you just want a better looking ceiling then why not just tack plasterboard over the existing? A couple of layers will help insulate for sound as well and no need to worry about meeting any regs.
Or batten out a inch and then double tack with PB.
A lot less mess as well!
Or batten out a inch and then double tack with PB.
A lot less mess as well!
Architects talk some sh!te.
Downlight fire covers are used to maintain the fire rating of a ceiling. It's the break in the ceiling thats the issue, not the cabling or the electrical fitting. No-one bothers fireproofing the teeny gap where wires come through for a pendant, but if you wanted to be anal about it, sealing the hole with a big blob of intumescent mastic would suffice. Boggo plaster would be perfectly acceptable though.
BTW if noise is the issue I wouldn't recommend downlights, regardless of whether fire/accoustic hoods are used.
Downlight fire covers are used to maintain the fire rating of a ceiling. It's the break in the ceiling thats the issue, not the cabling or the electrical fitting. No-one bothers fireproofing the teeny gap where wires come through for a pendant, but if you wanted to be anal about it, sealing the hole with a big blob of intumescent mastic would suffice. Boggo plaster would be perfectly acceptable though.
BTW if noise is the issue I wouldn't recommend downlights, regardless of whether fire/accoustic hoods are used.
Why does the ceiling need to comply with Part E? Are you converting one dwelling to flats or something?
If not the building inspector will be perfectly happy with what is there (even if it is in bad shape). In which case you could just overboard (or pull down the L&P and say that you just overboarded).
Re the wiring, yes cable usually runs above plasterboard. Normal light fittings do not require hoods in a domestic setting.
If not the building inspector will be perfectly happy with what is there (even if it is in bad shape). In which case you could just overboard (or pull down the L&P and say that you just overboarded).
Re the wiring, yes cable usually runs above plasterboard. Normal light fittings do not require hoods in a domestic setting.
blinkythefish said:
His response was that all lights(i.e downlights, pendants and batten holders) need a hood, which again I am pretty certain is wrong.
Downlighters for sure ...........If theres a flat above then you do need to ensure you maintain a 1 hour seperation .
As many others have already said , I would just board over the existing.
Hi, thanks for the replies.
We did consider reboarding, but the ceiling is pretty knackered already(existing strapping & plaster), and other work we are doing((re)moving walls, rewiring, and running ventilation fan ducts) are just going to add to the destruction. After a bit of consideration we decided that replacement would ensure that the sound issue is properly solved. The sound issue is pretty bad - can hear the neighbours talking - so it is worth ensuring that it is done properly, now, while the flat is being ripped apart anyway.
Well I've got a discussion with the architect today.....Think I'll suggest that his idea is b
ks.
We did consider reboarding, but the ceiling is pretty knackered already(existing strapping & plaster), and other work we are doing((re)moving walls, rewiring, and running ventilation fan ducts) are just going to add to the destruction. After a bit of consideration we decided that replacement would ensure that the sound issue is properly solved. The sound issue is pretty bad - can hear the neighbours talking - so it is worth ensuring that it is done properly, now, while the flat is being ripped apart anyway.
Well I've got a discussion with the architect today.....Think I'll suggest that his idea is b
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