i have just dug a channel in my concrete floor, through the kitchen, lounge & hall, which is about 6 inches wide, 5 or 6 inches deep, and
10 meters long (sorry for mixing metric & imperial), in order to lay the downstairs pipework for my new central heating system (i don't want any pipes/surface conduit boxing visible), and i was just wondering if any experienced builders out there could tell me the best method to fill it back in again now all the pipes/conduit boxes etc. are in place. The original concrete floor is about 4 inch thick, so obviously i've broken right through this to the loose hardcore/earth below, etc., so do i use sand, rubble, hardcore, some of the old broken concrete, just new concrete mix, or am i thinking all wrong...............all i want is to patch it up as it was before, with no chance of it ever coming loose/rocking under foot etc.sorry if this is a bit long winded, hope someone can help. TIA