Concrete around soil pipe needs repairing Drainage pipes, concrete, footings and foundations. Post your questions and find answers here

[Drumpowder]

Hopefully correct forum. The concrete around our soil waste pipe in the manhole is giving up the ghost. Its directly opposite where the waste water enters from the upstairs bathroom, so I assume over time it has slowly washed it away. Is it a case of just filling and finishing with quick drying cement? Any recommendations and any pre prep I need to do. Or is it a job for the professionals? Ideally needs to be pretty long lasting. We are not on mains seweage so need to try and avoid new concrete washing down towards the tank after only a few months. Will obviously block drainage entrance to avoid concrete washing down while working.