Polystyrene ceiling tiles

[pilsbury]

Hopefully moving into my new house in 4-6 weeks. A 1930's house in need of some modernisation! One particular thing that sticks out are the polystyrene ceiling tiles in all bedrooms. Not sure when these would have been stuck up but I'd guess 60's.

Either way I have a feeling they will be stuck straight onto the original lath and plaster. I also have a feeling that they will be stuck like sh1t to a blanket and end up ripping half the plaster down with them. I may be wrong and a scraper will just fetch them all off with ease to reveal a beautiful flat ceiling free from cracks and imperfections...... but you know the likely outcome!

What to do with this ceiling monstrosity? Board straight over the top?

 

[flameport]

Scrape the tiles off and board over whatever is left.
The adhesive will be hard as granite and impossible to remove.

 

[pilsbury]

OK - why scrape off the tiles first?

 

[roughcaster]

I stripped an old lath and plaster ceiling of old polystyrene tilesa while ago, and they came off no problem. I used a 4" inch scraper. The ceiling was then overboarded and skimmed. The reason it's advisable to remove these old tiles, is because they are a FIRE HAZZARD. They are very immflamable, and even though you're going to overboard the ceiling, it's very advisable to remove this hazzard.

 

[Doggit]

I can see where you're coming from rough, but if they're covered over, then the fire hazard is reduced, and any fire getting to them means that the fire brigade have been pouring water onto the fire for at least 15 minuted. If you check wikepedia, it'll say that polystyrene is acceptable if covered over by drylining, metal, or concrete.

 

[pilsbury]

I have heard they are a fire hazard, but covered by board and a skim would provide some protection enough for the smoke alarms to go off and me to get out.

I want to do a proper job, but with 4 large bedrooms, I think I'll be loosing the will to live.

Also, wouldn't they be extra insulation?

 

[roughcaster]

I agree with that comment Dogg. It would be difficult for the old tiles to catch fire underneath the plasterboard, , but I thought i'd still remove them.

 

[bernardgreen]

Old polystyrene tiles do not need to ignite to be a serious risk to people in the house during a fire. As I recall it when heated they can chemically break down and produce toxic gases which can be fatal. Would a smoke alarm detect these toxic gases before they reached dangerous concentrations ? I don't know but I certainly would not want to rely on them.

Fire brigades hate them as the gases they produce when hot are inflamable and when a fireman searching for persons in a burning building opens a door to a room full of this gas he can be met with a violent flash over as the gas spreads from the room and ignites. Some insurance companies have used the presence of burnt polystyrene tiles as a reason to reduce payments after a fire.

 

[pilsbury]

Points taken on board.