I am looking to buy a top floor flat and I have noticed the ceiling is bowing and floor sloping. I have noticed there is no loadbearing wall in the flat to support the butterfly roof above, which may be causing the bowing. However, I noticed other flats on the street have open plan spaces on their top floor and do not have loadbearing walls. Any ideas what could be causing it? The property was built c.1900. 

if you noticed - any harm in mentioning exactly the same to the vendor see what the story/history is?

 

+your own building survey (not just a homebuyers walkthrough)
 

 

If you are worried about it, so will the person you try to sell it to.

Maybe best to walk away now.

A butterfly roof doesn’t necessarily have a supporting wall, but sagging needs looking into, sloping floors point towards subsidence or rotting/failing joists or pockets

Needs a proper survey.