Excavation and existing concrete footing

[mcampster]

We are in the process of excavating our basement room - only to gain another 200mm but because we need to allow for 300mm of slab/insulation/screed we have had to dig down 500mm.

At 400mm we have reached to top of the concrete footings that the house is built on.

What are the regulations around this? Can I excavate the remaining 100mm knowing that we're then going to pour in 150mm of concrete? How far past the top of the footings can we excavate, if at all?

 

[mcampster]

We are in the process of excavating our basement room - only to gain another 200mm but because we need to allow for 300mm of slab/insulation/screed we have had to dig down 500mm.

At 400mm we have reached to top of the concrete footings that the house is built on.

What are the regulations around this? Can I excavate the remaining 100mm knowing that we're then going to pour in 150mm of concrete? How far past the top of the footings can we excavate, if at all?

...I will of course be getting the building inspector round to check up on each stage, I just want to get a head start on finding out whether I'm going to have to start planning for lower ceiling heights or not. I'll be a little gutted, but underpinning sounds expensive

 

[Phil189345985]

We are in the process of excavating our basement room - only to gain another 200mm but because we need to allow for 300mm of slab/insulation/screed we have had to dig down 500mm.

At 400mm we have reached to top of the concrete footings that the house is built on.

What are the regulations around this? Can I excavate the remaining 100mm knowing that we're then going to pour in 150mm of concrete? How far past the top of the footings can we excavate, if at all?

...I will of course be getting the building inspector round to check up on each stage, I just want to get a head start on finding out whether I'm going to have to start planning for lower ceiling heights or not. I'll be a little gutted, but underpinning sounds expensive

BCO chap will most likely want a trial pit dug to determine the foundation depth/makeup before making a decision.