Repairing a Concrete Slab and Tying it to the Footings
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djlucashome
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Joined: Mon Oct 07, 2019 2:34 pm

Repairing a Concrete Slab and Tying it to the Footings

by djlucashome » Mon Oct 07, 2019 3:09 pm

I am having to repair or replace the concrete slab floor in some parts of my house and looking for some guidance to give the building control the right spec to do the job

I have a problem with the floor dropping in the Kitchen area approx. half of the Kitchen floor area approx. 1.7 mtrs x 3.1mtrs dropped by about 15mm at one end
And I have the same in the lounge area about half of the room area room size 4.4 x 4.9 mtrs so 2 mtrs x 4.9 mtrs has dropped by about 30mm at one side

We have not dug a hole to investigate yet, but have been in touch with building control to see what we need to do, they are reluctant to offer advice and have asked me to seek independent help.

The property is a detached House built around 1969. The house itself hasn’t subsided as there are no signs of cracks in walls etc.

The house is in what was a Forrest, when we moved in in the early 80’s there were 50 Fir trees in the back garden, I cut down all of those and the stumps of the one’s that were in the lawn have now rotted down, they have left big dips in the lawn area of the garden. As there are no pipes around the Kitchen area I am guessing that the problem is most likely caused by organic material rotting and compressing, probably not cleared properly when the slab was laid. The building control Department have suggested tying the floor slab into the existing footings

So I believe that I need a specification for repairing the floor, to what would have been the specification when the house was built in 1969, allowing if possible for a simple way of tying in the slab to the existing footings

We have been told that we can repair the floors if the repair area is around the areas we have but if they get to be more than 25% of the area of the house they will need to be repaired to the new standard.

So in case I need to take up more of the floor than has dropped, a specification to allow for the Insulated layer and if possible an option to allow for underfloor heating pipes at a later date.

My plan was to cut a hole in the kitchen first and to see what is actually under the floor, however it seems academic if we are to replace with a floor tied into the floorings of the property as the slab will be stopped from any future dropping.

Has anyone had this issue before and repaired it successfully? Any suggestions gratefully received.