Drain flies - Revisited

[Rod]

A while ago I posted about a problem with drain flies that my mother has.

Well - today a major unheaval took place as an investigation was done by some professional drain people. Seems there was an object partially blocking the stack pipe/drain. Use of camera, all sorts of special tools, cutting the cast iron stack pipe, etc. resulted in the object being retrieved. After 3 men working for a most of a day - it was a piece of copper pipe. (No - I don't know what size.)

Trying to work out how it could be there, I can only come up with a builder accidentally (or even on purpose) dropping it down the stack pipe when the house was built - around 40 years ago. Seems more feasible than it coming from a pigeon or a low flying aircraft...

They also identified severe damage to the drain and a lot of stoney mess down there. (This is very much in line with what I thought was there when I tried rodding up that bit of drain.) It appears that, at the very least, the copper pipe has been slowing up the flow for many years.

I suspect that the drain was surrounded by loose fill gravel/ballast (not solid concrete). Damage (possibly caused by the copper pipe) has allowed effluent to escape into that and formed a hugely nasty undergound pond.

I am amazed at the total lack of any smell.

The drain people are hoping to come back tomorrow to install a new stack and drain. Hopefully all of this will be covered by insurance - seems that they are playing ball. (When they confirm that, I might mention their name.)

[Mary Fisher]

That's very interesting, I was wondering what had happend about it, thanks.

Mary

[Aidan]

Thanks for having the courtesy to post feedback. I've learnt something from the threads. . The problem turned out to be similar to that in the link you'd posted in the first thread.

've got a boggy bit of back garden, in line with the S&V pipe (enclosed in an extension) that I have to investigate. The garden slopes down towards the house, so it could be surface water.

The original 1930's cast iron inspection covers are hidden under floors and paving. Spent yesterday excavating one on the drive, to install the right cover, after Thames Water's contractors had lifted the cover & chucked paving back. They had promised to re-instate it; they lied.

[The Natural Philosopher]

Oh yes. Its dead easy to lose a bit of pipe down a hole.In my last house I walled up a large bottle of PVA glue in a stud wall, and Ive dropped a hole cutter ring AND a magnet retrieval device behind some cupboards this time...I know, because I saw him do it, that the brickie who built this one has peed in some off the brickwork cavities..what else might be in there (its a long way up the chimneys...

That is as it should be.

Why? underground is where all pongs stay unless disturbed.

I've got an old septic tank now completely buried under a few inches of soil

Absolutely the right thing, when its all been lifted and exposed.

Now is the time to add a manhole cover and an inspection chamber ready to run a new branch to that extension you always were going to have..