Thickness of plaster on lath ceiling

[MatthewC]

Please can anyone tell me how thick the lime plaster should be on a lath ceiling? I have just removed the plaster from two ceilings, and it was really quite thin - only about 10mm, typically, and maximum 15mm. Mike Wye and Co (in a DVD) recommend 2.3 cm; 10mm for the 3:1 haired scratch coat, 10mm for the float coat and 3mm in total for two (2:1) skims. That's quite a difference in thickness. I would have expected that it was better to have it fairly thin, but I suppose it could be why I've had to take it down...?

And how long do people leave between the coats?

Thanks

Matthew
http://houseintheenchantedforest.blogspot.com/

 

[Gervase]

I usually put the scratch coat on at about the thickness of the gaps between the laths - which is around 8-9mm. The float coat goes on at 5-6mm and the skim at 2-3mm. So the total thickness is anywhere between one and a half and two centimetres.
As for time between coats, ceilings dry faster than walls, so you can get away with just a couple of days to let it go green hard (hard enough not to be dented by a fingertip, but soft enough to be scratched with a fingernail) - much depends on temperature and humidity, however. Or you could leave it for longer to carbonate completely (my record is over a year between scratch and float!), but you'll have to wet it well to kill off the suction.

 

[robgil]

Isnt there a minimum requirement for fire regs?