My final problem before I tackle the patio!! Ive attached a photo that shows the set up, but I have a decking sandwiched between two patio areas, and I plan to take up the decking and timbers underneath and replace with a patio. The finished level is at or above DPC do I plan to fit Aco drains to take away any water near the house. I suspect when I take up the decking I might also find an air brick below finished level. The door sill’s are also under the decking so my problems are:- 1. Do I:- a) run a border and bring the Aco say 6 inches away from the door, or b) fit the Aco flush to the door which would need me to cut off the sill to give clearance. 2. How do I deal with the problem of an air brick below finished patio level? TIA