subsidence?

[legepe]

Hi all,
I viewed a 3 bed terraced property yesterday
The staircase leading to the first floor seems to have moved up in the middle around 2" (see pics) also the first floor going into the bedroom is bowed along the same line as the stair case.
I cannot see any other signs of movement ie: cracks on walls or the floor on the ground floor.
I would have thought if its the properties footings it would show signs on GF too?
Has anyone had any experience with something like this, what is the cause of it and what should I be looking for if I go back for another viewing
Thanks a lot...
legepe

 

[Blagard]

I have seen a few like that. Old terraced houses in areas that were once subject to subsidence. Since the old mortar is soft you rarely get cracks in the bricks and with property improvements walls get replastered and sometimes underpinned and generally made good. The end result is what you see. You need to know more about the property history and the local geology to understand if the issue could re-occur or if it was subject of a local authority renewal scheme. One street in an area I worked in had properties subject to unpinning all walls some 10 feet deep!- I would have thought it better money spent to demolish and rebuild to a higher standard as the end result was still a 100 yr old terraced house! - A classic case of politics and no common sense!

 

[legepe]

Thanks a lot for reply Blagard,
The area was severly flooded not so long back, also almost all buildings here are built on a flood plain (i estimate the building is around 1870sh)
Would a good/easy solution be to readjust the footing to drop the staircase back to level then fill in the whole gf void with a dpc and concrete to bond/hold all the buildings footings and create a new foundation? and would this be very expensive?

 

[Blagard]

The flooding you refer to is probably nothing to do with that movement which may have happened a long time ago. Remedial works would be expensive and you would still have a house that is crooked. I would not be supprised if the roof is all out of level too. Without a full survey and knowing what needs to be done I would walk away from that.

 

[legepe]

Thanks again, I will take your advice and leave it for the moment..

 

[MysticalGandy]

I went to see a property recently that had subsidence due to a tree root, successfully treated 18 years ago.. put me off cause the survey report was also 18 years old so I walked away from it... I also found a useful Subsidence Hotspot map online which shows the UK's regions with high subsidence - https://www.geobear.co.uk/uk-subsidence-map/

 

[ntl142]

In addition to that link is this one:

https://mangomap.com/geomatic-ventu...ingdom-relative-deformation-map?preview=true#