Our patio was made of concrete 8 metres wide by 5 metres long and 0.2 metres deep.The concrete was laid 50 mm below the DPC.
I have removed the concrete and a further 0.2 metres of bricks,paving stones used as hardcore.
I intend to replace patio with decking.
My problem is there are 2 manhole covers in the area.These were raised by 450 mm above the original ground level by oversailing 5/6 courses of house brick and concrete to reduce the opening from 1200mm x1000 mm to 650mmx450mm.
I need to reduce the height of the inspection covers by 400mm.
Just taking of 5 courses will get me to level ground but I then have a 1200x1000 opening that needs an inspection cover.
The chamber is 1.5 metres deep.
I presume I could take a further 5 courses and oversail with engineering bricks up till I reach ground level or take of 2/3 courses and use a biscuit to reduce the opening but I am really looking for advice on whether these options are correct or there are better alternatives.
Any advice would be gratefully received