corrugated slate in the attic between rafters?

ronaldmacdonald

Hello

I am pulling up all the ancient insulation in the attic (40's house) and have discovered waht looks like corrugated slate underneath it. Underneath this corrugated slate layer is wood. Why would the slate layer be there - most of it is breaking up and loose.

macman

Do you mean broken slate? If so it's from when the roof was reslated and some of the old slates have fallen through, broken and not been cleaned up.
The only wood should be that of the ceiling joists.

adonis

I have never heard of corrugated slate, i don't want to worry you but are you sure it is not asbestos.

ronaldmacdonald

adonis wrote: »

I have never heard of corrugated slate, i don't want to worry you but are you sure it is not asbestos.

:eek: I ruddy well hope not from the clouds of dust I have been in today - the dust mask was black! I dont think its asbestos - it doesnt seem strong enough its more of a tile substance - when broken looks like a weak cement mixture. Im worried now lol!

ronaldmacdonald

macman wrote: »

Do you mean broken slate? If so it's from when the roof was reslated and some of the old slates have fallen through, broken and not been cleaned up.
The only wood should be that of the ceiling joists.

This looks like it has been deliberately laid between the joists, on top of wood - i guess a normal house wood have plasterboard here that would form the ceiling of the upstairs rooms. The fibreglass was laid on this

ronaldmacdonald

I got worried and went back to check - it seems like a sandy/cement substance - in corrugated strips.

Images here and here

newbie1980

ronaldmacdonald wrote: »

I got worried and went back to check - it seems like a sandy/cement substance - in corrugated strips.

Images here and here

hi all

i think u will find its the old laughing plaster

its the way it used to be

it is horrible to try a nd fix to

dave

Cazza

newbie1980 wrote: »

i think u will find its the old laughing plaster

Isn't it lath and plaster??? Often you see horse hair in it, depending on how old it is???

ronaldmacdonald

Cazza wrote: »

Isn't it lath and plaster??? Often you see horse hair in it, depending on how old it is???

Yes there does seem to be hairs in it. So can I take it this is some sort of ancient insulation method from the 30s/40s. Cant undertsnd for the life of me what use it has on the attic floor.

DVardysShadow

ronaldmacdonald wrote: »

Yes there does seem to be hairs in it. So can I take it this is some sort of ancient insulation method from the 30s/40s. Cant undertsnd for the life of me what use it has on the attic floor.

It is the lime plaster from lath and plaster. It has not been applied to the 'attic floor' - and I hope you have not been walking on what you describe as the floor. This 'floor' is laths [thin strips] of wood nailed to the ceiling joists from the underside. When the lime plaster is applied to the ceiling, it is supposed to squeeze between the laths and produces the corrugations you describe. If you have been clearing these out or they are loose, you can expect your ceiling plaster to fall in due course. Ceilings have not been done like this for 60 years and most are coming to the end of their lives - a thought to bear in mind as to whether or not to renew the insulation.

ronaldmacdonald

DVardysShadow wrote: »

It is the lime plaster from lath and plaster. It has not been applied to the 'attic floor' - and I hope you have not been walking on what you describe as the floor. This 'floor' is laths [thin strips] of wood nailed to the ceiling joists from the underside. When the lime plaster is applied to the ceiling, it is supposed to squeeze between the laths and produces the corrugations you describe. If you have been clearing these out or they are loose, you can expect your ceiling plaster to fall in due course. Ceilings have not been done like this for 60 years and most are coming to the end of their lives - a thought to bear in mind as to whether or not to renew the insulation.

I didnt walk on it no! I managed to use a crawl board for this exercise.
I got worried again so went and checked the upstairs ceilings - they look sound from below. I guess if it drops we will use the opportunity to plasterboard. Although there are loose/broken sections there is probably enough support if i dont start whacking 7 shades out of the ceiling

Thanks for your replies - they didnt half do some weird things in these old houses.