Sulphate attacked floor. Survey needed?

[Steve]

I have what I suspect is a concrete floor that has been affected by colliery waste in the fill material and has suffered sulphate attack. It is extensively cracked and uneven, and where the hearths have been filled in the concrete has risen up by around 15mm.

Is it necessary to have a survey done on this or could I just employ a builder to dig it out and relay it? I have been quoted £1000 approx just for the survey and testing. Clearly the floor needs replacing, but do I need to find out whats in it?

As you can see the house is currently empty and undergoing significant refurbishment. This photo shows the living room but the kitchen and dining area and hallway are also affected to a similar extent.

 

[tomfe]

Why would you need to find out whats happening if you are replacing it anyway?

 

[Steve]

I guess the only benefit of getting the survey done is that it might not need replacing as such, and may be able to use a self levelling substance. What concerns me is that theres hundreds of these houses in the area and I've not heard sulphate attack mentioned. Though next door have said their floors are in a similar condition to ours.

I may get a local builder in to check it out and see if he knows of any cases locally.

If anyone will know they will. Ive read sulphate attack makes your house unmortgageable but we managed to get one and the valuation survey didnt mention anything.

 

[^woody^]

Surely you need to know whether to repair or replace just the slab, or if the fill below needs replacing too?

And also what has actually caused the slab to heave, and if the cause needs to be rectified too.

 

[tomfe]

Surely you need to know whether to repair or replace just the slab, or if the fill below needs replacing too

Why, at 1k you can get a brand new slab infill and insulation.

 

[^woody^]

Why, at 1k you can get a brand new slab infill and insulation.

Not done properly you can't.

The b/regs fee alone is a quarter of that, and the materials, hire and disposal more than the remainder. That's leaves the blokes not even working for nothing, but paying the other costs to work. Have you got their number, I've got lots of work for blokes like that.

 

[tomfe]

Going to take a guess at 15m2
100 for insulation 150mm eps
30 for DPM
120 site mixed concrete 150 ready mix(volumetric)
70 stone
Skip 120
270 2 labourers 2 days to remove concrete fill and sack stone DPM and insulation
200 1 labourer and a guy to lay concrete.

What am I missing?
BC, uhmm yeah right I'd just say it's under 25%

I bet you'd pay 150 in self leaving and you'd not have the benefit of a warmer floor.

 

[^woody^]

You wouldn't just do one room if the whole floor is experiencing sulphate attack.

And you would allow for removal of the fill and contaminated ground down to the foundation level.

The kitchen can be extremely costly.

That's what you are missing