Big Crack inside

[Othompson]

I’m looking at buying a house, it’s been extended to the rear by the previous owner.

In one of the bedrooms there is a big crack as seen in the second photo which bulges out allot. I don’t think it’s subsidence no stepped cracking or the the extension separating from the main building which would be a big vertical crack.

I can’t see the outside to confirm however, as the crack is in the equivalent location of the blue dot on the second photo, with the neighbours extension blocking it

Anyone got any ideas on what could be causing it, you can’t tell to much on the photo but it is a signifiant crack

 

[Wayners]

Definitely blown plaster from movement I'd guess.
Would need to remove plaster. Fix wall. Maybe repoint or whatever I'd required. Skim.

 

[Othompson]

@Wayners, do you think that would just be the extension settling then ? Rather than something more serious

 

[Ivor Windybottom]

Impossible to tell from the photo but looks scary.

Has the plaster detached from the wall, does it sound hollow when tapped?

My best guess is that there's structural movement of the wall.

Any signs of movement in the room below?

Flat roof will be a pain anyway, assume it needs re-roofing. It's possible that it's expanded in the sun and pushed the top corner off the wall. Ours had done the same, in our case it had pushed the top course of blocks off the internal wall. But in our case you could see the outlines of the blocks through the cracks in the plaster.

I'd run away, unless it's silly cheap.