I am building a terraced patio. 2 levels with a stepped concrete footing and base built from blockwork. Base filled with hardcore and then slabs laid on top. Because surface water won’t be penetrating. Do I need a perforated pipe around the inside of the base walls with weep holes? I also have built a 4 course night 9inch thick brick walls up to the path which is lever with the house so the patio is lower. Should I put a pipe behind that wall also? As technically the surface water drains off into a drain so the soil underneath isn’t soaking. Any advice would be appreciated as I worry I am overthinking this