replacing clay pipe into inspection chamber?

[ladwey]

I need to make a small change to the direction of a soil pipe as it enters a sturdy old brick inspection chamber (private sewer, on my property). I've dug down past the bottom of the pipe; it's bedded in a large bit of incredibly hard concrete on the outside where it enters the chamber. Unfortunately it's an old clay pipe that seems to have a fine crack in the underside that runs right up to where it enters the concrete, so I guess it won't work to cut it off around there leaving a stub long enough for a clay->plastic transition (as I presume it will be finely leaking under the femco coupling). I also doubt it will be possible to break up the big mass of concrete to reach an undamaged section of pipe to cut without also cracking the pipe in the attempt. Is the best thing to do to break it up and chisel it out right through into the inspection chamber, leaving a hole large enough to get a 110mm plastic pipe through instead, then fit that through and seal up and make good so there's no bump or gap at the transition?-- if that's the case, is there a particular sand and cement mix I should use (or would it be the stuff they call grano)?

 

[Hugh Jaleak]

Given your description, complete replacement into the chamber sounds like it will be the best method, hardly worth patching that small section of clay pipe if it is just as easy to replace. You may find breaking out the clay, given the width of the pipe walls, it gives you enough room to get the 110mm plastic through without too much ado.

Making good, fill in the big voids with concrete, then repair the benching with a strong sand and cement mix. It's hardly worth buying a bag of Grano dust if you're only repairing a small area, unless you've other uses for it.

 

[ladwey]

That's roughly what I thought, great to have it confirmed -- thank you.