Hi guys... I'm in the process of redecorating a room. Three of the four walls of the room are in perfect condition, one of which is external. On the fourth wall (also external) however the plaster had started to crumble away, just in the space above the window... In order to fill and replaster I pulled away all the loose plaster, which took me right through to the wall itself, the stonework of which also seems to be crumbling away, is cracked, sounds hollow, and even flexes a little when pushed. The fact that this is an external wall makes me even more worried.
The house is around sixty years old, perhaps more, and is pebbledashed from the outside, so I can't see what damage is or is not occurring. The wall isn't brick, and doesn't look like breezeblock either, just like grey concrete or something.
Sorry that I can't give clearer details, I'm generally a bit confused by the problem... do I need to get someone to come and look? Is this relatively common in older houses and something that can be sorted simply? Can I overlook it, like I said, the remainder of the wall seems fine?
All help incredibly appreciated.