Uphill kitchen floor?

[ochickey]

Just got the keys to my next renovation project and the first obstacle is that the kitchen floor (concrete slab) runs uphill by about 100mm over 4metres. Its a damsight less worrying than if it was sunken by that much but it needs sorting.

Why might it be like it? Its in an old double storey extention at the back of a terrace... surely it wasnt built on the p*ss?

Sounds stupid but... How do I go about sorting it?

 

[noseall]

Uphill or downhill is subjective.

Could be clay heave or sulphate attack or poor workmanship.

What are the soil conditions?

Any history of red ash infill? I guess there is history of nearby coal mining...yes?

Heave problems can be equally as worrying as subsidence

 

[ochickey]

thanks for the reply and good point, it is subjective! The house is perfectly level until you step into the extention and over the 4m span away from the back of the house the slab goes uphill.

Coal mining report suggests no problems and the house is in the middle of a row of terraces, neighbours have no problems also. There are no cracks or obvious signs of movement on either storey.

The existing kitchen has had the splashback tiles cut to match the inclining worktops! (easily a 15yr old kitchen)

Should I be concerned? and what steps to rectify.

 

[joinerjohn]

I fitted a kitchen in an extension, built by a supposed professional builder. The concrete floor was 100mm out of level over 3m.
(BTW it looked dreadful ) the floor , not the kitchen.

 

[noseall]

Coal mining report suggests no problems and the house is in the middle of a row of terraces, neighbours have no problems also.

My reference to coal mining was more to do with red ash than to do with subsidence.

In our area (also a historic coal mining town) NCB purpose built housing used red shale as infill on a lot of the houses. The shale or red ash is a by-product of coal mining. The spoil from the pit would be piled on heaps and coal residue in the heap would combust producing red shale or red ash.

This resulted in sulphate attack to the floors in a lot of the houses. All have had to have their floors dug out, the shale removed and replaced.

 

[JohnD]

A kitchen is going to have water pipes and/or waste pipes under the floor. If one of these is leaking it will wash away the soil and make a large hole that the floor, or even the house, can fall into.

You know you've got to take up the floor, so you'll soon find out the cause.