Slopping concrete first floor...floor levelling

[dgardn]

Hi,

I was hoping somebody here would know a little about what im dealing with here. I own a flat that I rent out. The living room is around 12ft square. The floor in here is extremely unlevelled, it slopes from all angles of the room so basically the centre is approximately 3 inches lower than the sides of the room. if you place a ball near the wall, it will always roll to the centre. The flat is part of a converted 1873 built railway house, so very old.

I asked a flooring specialist that's doing another job for me the best way to level it up, and he recommended building it up in layers using a latex screed, at an approximate cost of £200. Which sounds very reasonable as and when a time comes that the flat is between tenants.

The floor hasn't moved at all in the 10 years I have owned it. My aunt had it for about 15-20 before I brought it from her, she never experienced any movement. I used to know the previous owned of the flat below and the ceiling down there isn't dipping although could have been battened and plaster boarded. One thing I did note when I was in there once is there is a large wedge shaped structure in the ceiling that extends out from the chimneybreast and across the room to nothing. This wedge shaped structure is dead centre of my room upstairs. The only thing I can think of is that when the flats were converted the removal of certain walls downstairs had caused the floor/ceiling to start moving and this structure was introduced to stop further movement,

Would it be advisable for me to contact a structural engineer before adding the weight of the screed to the floor above. Or is it safe to assume it can take the weight since its not moved in over 40 years since the conversion took place. Its a large dip to level, but it is something that needs to be done at some point as it limits what furniture you can have in the room.

Does anybody know of a light weight way of levelling the floor, or a light weight way of building up the majority of the dip so a screed can go over the top?

Sorry I don't have pictures, the tenants down below aren't the most forthcoming people. The chances of getting a picture of there ceiling is slim, so I hope my descriptions are detailed enough for somebody to advise.

Thanks
Darren

 

[theprinceofdarkness]

What happens when you jump on the floor, it sounds as though its just too weak. If it does not bounce then its strong enough but just the wrong shape, so self levelling screed might work. If it bounces then I think the screed will crack around the edges and the whole will come loose.
I would lift the all floor boards and manufacture wedges to nail onto the joists, before re-laying the floorboards. A bit OOT? A decent wood yard will cut a pair of wedges out of a piece of wood by cutting it down diagonally on a bandsaw.
Frank

 

[dgardn]

Hi, the floor is concrete in the living room. Under the carpet there are a couple of cracks but it does look as though the slope has been poured/layed like that. The majority of the surface is fine, the couple of cracks there are are old that's why i wondered if it once was moving. Around one wall the flooring has cracked as well. If you jump it doesn't really bounce as such, when i had a survey done years ago it was noted there was some deflection though. not sure what that means exactly. The floor appears sturdy, just oddly shaped. Somebody once said that there would have been a slab over the dipped area since back in the day it was all open fires. I don't know whether that might explain the shape. The flat on the other side though is flat, but i suppose all that might mean is somebody levelled it at some point

Darren

 

[OwainDIYer]

What is the actual structural floor support? Someone hasn't just poured concrete over some old beams and boards have they?

I think you need a structural engineer (not a surveyor) with experience of old buildings and conservation work to carry out some investigation (which may involve opening up part of the floor structure from above and/or below) to find out exactly what's supporting what.

 

[dgardn]

The majority of the floors are concrete, with the exception of an area in the kitchen that is floor boarded where the old staircase would have been. The floors in the bedroom is concrete, and perfectly flat. The bathroom is on the wonk in one corner raised rather than slopped. However the floors have been done i believe they are how they were in 1873.

The flat below has had a substantial amount of walls removed and or altered when they were converted. RSJ beams were installed to support the weight of the walls above.

Slightly off topic one of the ground floor flats on the opposite side to mine suffered 5-6 major explosions around 18 months ago. Even the plaster on the walls and ceiling were reduced to dust, nothing survived other than the bricks and mortar, and of coarse the concrete ceiling. The owner of the flat had structural engineers in to assess if it was safe, passed without question. so its unlikely to have been poured over wooden boards i would have thought.

Its an old railway house that everyone including builders have told me they used to use top quality materials on these houses and they were built to last. It probably would be a good idea to check with a structural engineer before any attempt at levelling it undertaken. Just wondered if anybody had and ideas

Darren