I've just dug the trench for my small front extension. My water pipe crosses the trench right where the concrete will go. My thoughts are a bit of waste pipe to sleeve it, or some insulation to allow a bit of movement. Any suggestions?
I think the waste pipe with insulation might be an idea, then you can always thread a new one through later if necessary. If you look in the approved documents there's a diagram in the drainage section which might give some suggestions.