I need to route a 110mm drain pipe accross the entrance to a lockup garage. I can only dig down 200mm, owing to the wide footings. So I envisage embedding the pipe in concrete, perhaps with some steel reinforcing mesh for good measure, but if the pipe ever got damaged in any way - say, where it exits the solid concrete, it would be extremely difficult to remove and replace it. So I'm thinking of embedding a slightly larger diameter pipe in the concrete (say 130mm dia), through which the 110mm pipe can be pushed.
Yes, I *could* bury the pipe deeper, beyod the reach of the footings, but it would be a big hassle, and would get untidy, as the pipe really needs to stay as close to the wall of the garage as possible, with no sharp bends.
It appears that the next size up from 110mm in foulwater drainpipe is 160mm - but that would be too big for my purposes, as the maximum depth I have to work with is only 190mm, and some of that (say 50mm) should ideally be concrete covering the pipe.
Can anyone suggest where I can get 3 - 4m of 130mm dia pipe (cheaply)?