Floor 'sinking'

[bluesteve52]

Old terraced house. Near window in back room (solid floor) floor has sunk slightly. On inspection carpet has been laid on top of tiles which appear to have been laid on soil.
Would it be acceptable to use a levelling compound on the section that has dropped or do I need to remove tiles and use levelling compound/concrete for whole room.
Thanks

 

[tell80]

Why not ask the mods to move this post to the building forum?

It wasn't unusual for tiles to be laid on soil in older properties.
Are there any damp signs on the carpet or skirtings or lower wall plaster?
Is there a gap below the skirtings?
If you posted pics of the floor with the carpet drawn back it would help?

As for remedies the options depend on how bad things are, and your budget.
Typically, when we meet this kind of situation at work we dig out the floor, and usually pour an insulated concrete slab on a Damp Membrane

 

[bluesteve52]

Thanks for reply. Yes there was a gap between carpet and skirting and yes the lower wall has signs of damp.
I will get someone in but keen to keep cost down. I'll probably remove tiles myself. Would I need to go much lower ?

 

[Deleted member 292770]

Typically, when we meet this kind of situation at work we dig out the floor, and usually pour an insulated concrete slab on a Damp Membrane

Which would be the typically wrong thing to do. Lets assume you have stone or solid walls with no dpc, which is most likely given the situation with the floor. Then a well ventilated ,insulated , suspended timber floor would be more in keeping with the age and style of the property and be more likely to help rather than exacerbate your rising damp issues with the installation of a concrete slab .
Any change of structure to the floor is notifiable to building control.

 

[tell80]

Yes, you could definitely remove the tiles, & all around the room skirting board.
Thresholds might cause you difficulties - likewise cables and any pipes.
Ground level outside should be lower than your inside FFL.
Digging out is doable but pics & more info needed before advising you further.

 

[bluesteve52]

The tiles had been up for inspection so gap looks a little worse than it was.
Would concreting the sagging area and then laying some kind of insulation over the whole floor be an option ?
Thanks

 

[mrrusty]

It's probably not just soil - more likely sand/cinders over ground. It has certainly dropped. I think it depends what your plans are for the house. It really needs taking out and rebuilding, as has been said, insulated concrete slab is certainly an option. Unless you're looking for a quick bodge, get it dug out. It would be good to work out why it has dropped too, because there will be a reason.

 

[^woody^]

That's how old terraces are.

You can either repair it and forget it, or rip the whole floor up and put a modern one in.

Bear in mind that those old quarry tiles are the damp prevention layer

 

[tell80]

bluesteve52,

Thanks for the pics.
I'll advise you how to do a proper job, and you can use the advice to do a full job or take what you need from it?

1. You have damp in the wall.
2. Remove the skirting.
3. Knock off the plaster along the wall to 300mm above the last signs of damp.
4. Render back up with a 3:1 sand & lime mix render - dont use gypsum plaster.

5. Remove the doors and thresholds.
6. Open up the top surface of the floor.
7. Dig down deep enough to allow for Insulation, a membrane wrapped 125 - 150mm of concrete, & whatever will cover, eg tile, the finished surface.
8. Your FFL should be level with both adjacent rooms.

Search outside for any factors such as gutters, gullies, various pipework, & cracked or bulging brickwork or render etc that might have had a hand in why your floor slumped.

 

[^woody^]

LOL

 

[bluesteve52]

Thank you, all. Plasterer already booked so an additional job for him.