Laying a concrete floor Drainage pipes, concrete, footings and foundations. Post your questions and find answers here

[Find_ben]

I am thinking about laying a concrete floor in my cellar to convert it into a utillity room. The current floor is made from brick and is far from level, it is higher in the centre than at the edges. This posses a problem as my head is already touching the celing. I understand I will need to remove the brick work and may have to dig down far enough to accomadate hard core through to a screen, depending what is underneath. This is shown in the ground slab project, however it doesn't give depths for each layer can anyone help, as I would like an idea how far I would need to go if I decided to contract a builder to carry out the work.

Many Thanks

Ben

[thedoctor]

You need to explore first as its vital that your new excavation does not go down further than the foundations of the property. If it does you need specialist underpinning. The sub base is usually 150mm thick and compacted to refusal, ie will not go down any more, the sand blinding usually 30-50mm and the slab 100-150mm. There are no dimensions on the project because they alter with ground conditions and its also vital that any Damp proofing is in place to stop water rising up between slab and walls.

[Find_ben]

Would I still require an underpinning expert if the finished level of the new floor was above the bottom of the foundations, but I had to dig down below that level to put in the sub base and sand blinding?