Starting to excavate to extend existing patio. New top surface will be 50mm woburn rumbled setts, and only have foot traffic, no vehicles.
Have read that the sub base s/b 100mm MOT Type 1, but also read that 50mm would be sufficient. I expect to find hardcore under the existing patio, but what depth would be best for the new area - it has only ever been tarmac & gravel, and was previously a driveway.
Also, existing patio height is very close to DPC level, but never had any problems with damp penetration. Wall is roughcast, rather than brick. Should I consider leaving a 100mm gap for gravel, or can I lay the setts right up to the wall, givden I've not had a problem so far? (which I know doesn't rule out a problem in the future)
Many thanks for any advice
Have read that the sub base s/b 100mm MOT Type 1, but also read that 50mm would be sufficient. I expect to find hardcore under the existing patio, but what depth would be best for the new area - it has only ever been tarmac & gravel, and was previously a driveway.
Also, existing patio height is very close to DPC level, but never had any problems with damp penetration. Wall is roughcast, rather than brick. Should I consider leaving a 100mm gap for gravel, or can I lay the setts right up to the wall, givden I've not had a problem so far? (which I know doesn't rule out a problem in the future)
Many thanks for any advice