I'm installing a gravel patio with a base of type 3 (improve drainage) and a stabiliser (core-gravel etc).
It appears the original bitumen DPC is actually level or slightly below the current concrete flag patio, with the brick course immediately above this showing significant damage. Where the render has its bell cast, immediately below, the final 2 courses of brick have had a light render coat. (this was all done way before we bought this place).
The bitumen DPC on the main part of the house (side return below french doors) is a brick lower than the kitchen DPC.
If I were to lay the patio at the recommended 150mm below DPC at the kitchen, there will only be 2 courses of bricks to the bottom of the footings (a number of courses more shallow than the main house.
Also, with there being a difference in DPC height between the kitchen and main house, there would only be a 75mm gap below the DPC below the french doors.
My questions are:
Should I be concerned with being only 2 courses from the bottom of the footings? Obviously I'd have to dig down at least a course to lay the sub base.
Although not ideal, is a 75mm gap to DPC acceptable in some circumstances? i.e. when using a gravel as covering?
I've got a short time to get this completed so hoping to crack on asap. I've attached some pics which my bring some much needed clarity!
hell boy with timber floors the dpc is often 2 course lower than you would expect because they laid the joist on DPC
you should work your 150 down from the finished floor height of the kitchen
dont forget gully surrounds to stop gravel getting into the gullies
LLL
So, that would mean me digging down and leaving only the final course of bricks (footings) not exposed. Is it then OK that I lay some type 3 only 75 mm from the bottom of the footing? Sorry for sounding like a novice, I'm just nervous about digging near the footings!!
The kitchen suspended floor was removed in the past sometime and replaced with concrete. However, I replaced the whole living room floor which is now independent of the external walls, so no joists in contact anywhere.
I've compared our drain to next doors and the levels are as expected, our patio was laid 150mm too high! No wonder the bottom course of bricks are fooked.
Thanks for you help mate, hopefully I can get cracking soon so as not to upset the missus, got a week left and counting!
