Hi
I'm undertaking an extension and am currently working on the internal foundations. I have a new pier to construct and have dug down about 500mm from finished floor level down to some really hard clay. this is about 200mm below the existing foundations. I will be replacing the floor in this room and will be digging out to 450mm deep with construction being 150mm hardcore 25mm sand, 100mm concrete, 100mm insulation and 75mm screed (with UFH). What is the best level to set the foundation at? I was thinking 175mm below FFL as this would tie in with the top of the concrete slab and the insulation would then sit on the slab and the bit of the foundation. However, I realise this would be a bit of a nightmare for coursing with bricks. What are your thoughts?
Thanks in advance
Ad
I'm undertaking an extension and am currently working on the internal foundations. I have a new pier to construct and have dug down about 500mm from finished floor level down to some really hard clay. this is about 200mm below the existing foundations. I will be replacing the floor in this room and will be digging out to 450mm deep with construction being 150mm hardcore 25mm sand, 100mm concrete, 100mm insulation and 75mm screed (with UFH). What is the best level to set the foundation at? I was thinking 175mm below FFL as this would tie in with the top of the concrete slab and the insulation would then sit on the slab and the bit of the foundation. However, I realise this would be a bit of a nightmare for coursing with bricks. What are your thoughts?
Thanks in advance
Ad