Uneven solid ground floor - just level or dig everything up and start again?

[dave163]

Our Victorian terraced house has a solid Minton tiled floor in the hallway and dining room which presumably was laid straight onto compacted earth/ash/debris. Sadly over the years it has sunk unevenly, and the deepest bits are now several centimetres lower than the surrounding parts. Having been advised by a Minton restoration specialist that it's too badly damaged for him to fix, we approached a builder who we trust as he's done good work for us in the past at a good price. His advice was to rip up all the tiles then dig up all the compacted earth under them down to about 50cm and fill the void with concrete. As it's all indoors it will be a huge amount of manual labour, and it's coming in at well over £10,000 even before we consider the cost of a new floor (carpet, tile, wood or laminate).

As the floor is a trip hazard in its current state despite being carpeted, something certainly needs to be done. I originally wondered if leveling compound would do the trick but perhaps the builder is thinking that too would crack if put down straight onto the uneven earth. But the quoted price seems a lot to make a few (well, quite a lot of) floor floor tiles safe. I haven't asked for any other quotes as I'm thinking that if this really is the best solution, our man will do a good job, and if we get a much lower quote we may end up with an unsatisfactory repair. On the other hand maybe there are alternative options he hasn't thought of?

For what it's worth, other downstairs rooms have original floorboards that are around 50cm above a layer of soil/rubble. There is no basement anywhere.

 

[vinn]

So, do you have a solid floor across the front of the terraced house - which means you have no through ventilation, only whatever ventilation can be provided from any rear elevation air bricks to ventilate the suspended floor area.

Done slowly & carefully, lifting the tile should be a relatively straightforward job - which means the hall and front/dining room need digging out, compacting, DPM, insulation and concrete poured to the desired thickness and level.

110mm venting pipes, from the 500mm depth rear subarea to newly fixed front elevation air bricks, can be installed in the concrete. - they will provide the rear area with through ventilation.

All that can be done for quite a bit less than "well over £10,000"

 

[dave163]

Thanks for response. The front (living) room has a suspended timber floor (ie joists and floorboards) and having replaced a few floorboards I can say that there is dust/debris/topsoil about 50cm below the floorboards. Can't say I've noticed any external airbricks so I don't know whether the underfloor space gets any natural ventilation, but there is evidence of a dampproof course in the outside wall.

Running along the side of the front room from front to middle of house is the hallway which has the solid floor (presumably) on compacted earth, and it leads at the end to the dining room which also has tiles and a solid floor. In both rooms the floor has sunk in some areas, to a depth of several centimetres and a thick carpet and underlay can only go so far in concealing the fault. We haven't sought further quotes (yet) as our builder has done a good job at a good price several times before for us and is not the sort of guy that would take us for a ride, but in this case it just seems very expensive. If there's a cheaper way of getting the floor leveled that would result in a permanent fix (does he have to dig out 18 inches of topsoil for instance?) I'd welcome thoughts on what could safely be compromised.

 

[Tigercubrider]

What volume of spoil are you talking about?
Is some diy on your part a possibility?

I'd have a go at lifting some tiles to see how hard it is as the economics of near archeology make it more a diy task
It is possible as a mate did it . Loads of photos and try to find a source of genuine old replacements . Is the dining room all tiles? Use one as a donor for the other?
I love tiled halls

 

[dave163]

Volume of spoil would presumably be around 10-15 cubic metres as we're talking digging down upto 50cm and a floor area of 25 square metres. Seems a lot and I'm guessing the quote reflects the amount of digging - can't really drive an excavator into the house! If we asked the builder to cut the cost by not digging so deep do we run the risk of not having a thick or strong enough concrete base, that might sag over time? Don't mind DIYing but simply haven't got the time to dig out that much spoil.

Minton floors are stunning and I'm pained to see it go. I sought professional advice to be told the hall floor was too badly damaged (lots of tiles have cracked) to put back down again and he wasn't even interested in recycling it. Dining room has different type of tiles, 6inch square terracotta colour. Probably same age as the house as originally it would have been the kitchen, but they won't substitute for damaged hall tiles.