Not many responses in the groundwork thread, so I'm trying here!
I'm currently renovating the basement, including lowering and insulating the floor. The house is from 1912 and the concrete floor was about 5cm without insulation underneath. Once in 5 years during very heavy rain, a little water came in one of the corners, so I thought of doing proper drainage. The builder has now drilled and snail-blasted rock to make room for my 5cm of gravel, 20cm of Isodrän, and then a 10cm slab. However, the slope of the rock was such that it tilted inward in the terraced part, so now the builders have done as shown in the picture. Is it normal to lay a drainage pipe, cast a slight slope towards the pipe, and then put gravel, etc., on top? It becomes a slab on a slab?
I'm currently renovating the basement, including lowering and insulating the floor. The house is from 1912 and the concrete floor was about 5cm without insulation underneath. Once in 5 years during very heavy rain, a little water came in one of the corners, so I thought of doing proper drainage. The builder has now drilled and snail-blasted rock to make room for my 5cm of gravel, 20cm of Isodrän, and then a 10cm slab. However, the slope of the rock was such that it tilted inward in the terraced part, so now the builders have done as shown in the picture. Is it normal to lay a drainage pipe, cast a slight slope towards the pipe, and then put gravel, etc., on top? It becomes a slab on a slab?
