Black coating on ceiling under wallpaper

[yorkshirelad]

We have recently started decorating a room in our house (built ~1900) when we stripped the wallpaper from the ceiling there was a black layer which in the most part flaked off. In some areas it will not come off at all. Could anyone tell us what it is, or how to remove it? We have tried chipping it off and sanding bit with no luck. Thanks

 

[JohnD]

might be soot, if there has been a house fire or a smoky grate

might be mildew.

might be a damp-proofing coating, such as a bituminous or synthetic rubber paint.

It might even be paint, if the house was formerly owned by a Santa-worshipper.

You may be able to identify by smell, or clean it off with bleach, or soften it with white spirit, depending which it is.

 

[yorkshirelad]

Thanks for the quick reply, its certainly not soot. where it came off ok, it was a fairly thick coating. It sounds like a bitumen or rubber like coating. I will try white spirit or possibly paint stripper, maybe that will shift it. Thanks

 

[Zampa]

JohnD is right and has made the right points, but its difficult to guess without a pic..any chance of posting one up?

 

[yorkshirelad]

Hi All, Thanks for your help. We had a plasterer around for a quote. He said it was old fashioned bitumen back wallpaper to keep out the damp.
Thanks for your sugesstions, much appreciated.