Good Afternoon All,
Wondered if anyone might have some input on this, I've just replaced a short section of drain at the side of the house for the soil stack. The estate is circa 1930's onward combined sewer with original drains using VC pipe.
This was the original situation, at some point in the past someone has undertaken a pretty shoddy partial conversion to PVC, No proper rest bend at the foot of the stack and poor support.
However the join to the VC was not clean, they just bunged the adapter over a section which had a piece cracked out.
As is frequently the case with these old VC installations the only support for the length of VC was some bits of half brick underneath. The soil is very clay rich and the long term slow leak from the union appeared to have resulted in settling of the upper VC section leading to cracking of the socket on the next VC section down.
I've removed the top VC, dug down and cut of the cracked collar of the next VC section flush and put a new PVC to VC union there.
My intention was to install a small inspection chamber howevr the job was complicated due the unearthing the MDPE gas pipe which I presume was renewed by mole at some point in the past without consideration to what else was in the area.
As you can see the situation is now as illustrated. The plastic follows the same angle as the existing VC down to the sewer and a branch has been made which I will be extending to fit a rodding eye.
I'm now after advice regarding backfilling, I have read through the advice at Paving Expert and Drain Domain. It would seem to indicate that at the proximity and depth relative to the foundation I should be looking to encase overall in concrete to protect the foundation against settling of the soil.
I would appreciate any thoughts on the best way to backfill this properly including if concrete is required.
I had considered close wrapping the run in a geotextile and then back filling progressively with concrete to support the pipes with flexible boards at the unions as suggested in the above sites. Is this overkill or best option?
I figured the geotextile would not impare the ability of the concrete to support the pipe but would make excavation easier without damage if future repairs were needed.
Thank you in advance for any thoughts!
Wondered if anyone might have some input on this, I've just replaced a short section of drain at the side of the house for the soil stack. The estate is circa 1930's onward combined sewer with original drains using VC pipe.
This was the original situation, at some point in the past someone has undertaken a pretty shoddy partial conversion to PVC, No proper rest bend at the foot of the stack and poor support.
However the join to the VC was not clean, they just bunged the adapter over a section which had a piece cracked out.
As is frequently the case with these old VC installations the only support for the length of VC was some bits of half brick underneath. The soil is very clay rich and the long term slow leak from the union appeared to have resulted in settling of the upper VC section leading to cracking of the socket on the next VC section down.
I've removed the top VC, dug down and cut of the cracked collar of the next VC section flush and put a new PVC to VC union there.
My intention was to install a small inspection chamber howevr the job was complicated due the unearthing the MDPE gas pipe which I presume was renewed by mole at some point in the past without consideration to what else was in the area.
As you can see the situation is now as illustrated. The plastic follows the same angle as the existing VC down to the sewer and a branch has been made which I will be extending to fit a rodding eye.
I'm now after advice regarding backfilling, I have read through the advice at Paving Expert and Drain Domain. It would seem to indicate that at the proximity and depth relative to the foundation I should be looking to encase overall in concrete to protect the foundation against settling of the soil.
I would appreciate any thoughts on the best way to backfill this properly including if concrete is required.
I had considered close wrapping the run in a geotextile and then back filling progressively with concrete to support the pipes with flexible boards at the unions as suggested in the above sites. Is this overkill or best option?
I figured the geotextile would not impare the ability of the concrete to support the pipe but would make excavation easier without damage if future repairs were needed.
Thank you in advance for any thoughts!
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