Drainage Repair - question about underground pipes

[dormermike]

Is there any benefit to plastic over prefab concrete?

Access not great so will be a manual effort, being quoted 2-3 days so far

 

[Hugh Jaleak]

Fingers crossed then there is no old lead services merrily leaking away. I would expect the water to be running constantly if such a leak was present so hopefully it is down the the broken drainage. Excavating should prove how serious the water issue is, doesn't look ridiculously deep so if hand excavation is the order of the day then should be fairly straightforward, just labour intensive. Micro digger will fit through a doorway, so would have to be a very small space not to be able to access with a machine.

As to sorting it out, then plastic = speed. Existing chamber can be pulled out, plastic chamber base fitted and joined to existing 'through' pipework with Flexseal couplers, drain can be used straight away. Branches for ground floor WC and gulley(s) can be connected at leisure. The existing rainwater connection at high level could be altered to connect as required.

To use concrete sections would require a channel setting in a concrete base, this would need to be allowed to go off before adding the risers, and benching the chamber. Would be several days work, drainage would need to be bypassed (or not used) whilst concrete cures. Ok for 'new' work but awkward for a drain already in use.

I think you need to get this lot fixed and see what effect it has on your damp issues before looking further. Older drains were laid with mortar joints which offer no flexibility for movement, hence when slight settlement occurs over the years they can crack.

 

[ivixor]

Yep. I wouldn't bother with digging up your floor slab - just core drill a new hole for the soil from toilet, straight out wall, down into ground, then into new plastic IC. You can also add a new gulley into this pipe using a Y connector.

No messing about with concrete, benching, etc etc, and minimum of mess inside the house.

 

[dormermike]

I guess thats the bit im struggling with, to some degree - why can't the ground "behind" the IC (on the gully side) be excavated and a new entry, or even use the existing gully "hole" removing the clay existing if its broken, be used as an entry point into the IC, and convert the broken gully into a soil stub stack with the sink/shower plumbed into that.. in other words, why is a new IC needed? Brickwork looks OK, sure it could do with some benching maintainance, but a new IC altogether seems a bit extreme.

Like this, if i have my terminology right:

I guess if i cracked on and dug down, i might be able to answer that myself.

Or does the IC chamber really look well past its best?

EDIT: one of the quotes i'm waiting on will assess if a "no dig" patch is viable. Any thoughts on these, seems like the crack might be a candidate?

Also my insurance is a bit vague on whether any of this is covered or not, i'm sort of resigned to paying it myself as the toilet at least is probably wear and tear, though the gully pot itself is physically smashed and I think that could have happened during the laying of the block driveway in 2008 which is right on the edge of the damaged part.

 

[Hugh Jaleak]

Chamber is probably salvageable, but the postion of it from what I can ascertain from the photo's, in relation to the building may give rise to space constraints for accessing the pipework entering from the house side. I would also be concerned about the integrety of the connections into the chamber, ultimately it is your decision on how much you want to do above what is absolutely necessary.

Personally, I would be changing the lot, TBH any savings made by keeping the existing chamber would probably be lost in terms of extra man hours trying to work round it. Also depends if the current chamber can be broken into without causing further damage or if adequate pipework can be accessed outside the chamber to connect onto with the new pipework.

Patching/lining is probably ok for long straight runs, but i'd be unsure if it would be cost effective (or even viable) for short runs with several bends as in the gulley connection. I would see what the quotes are you receive, and go with what suits you best.

 

[dormermike]

Have had one quote so far - 1100 quid - and two others have looked at it and said they'd be interested in the work but haven't been seen since, not responding to calls, emails etc - highly unprofessional IMO but could look on it as a lucky escape.

Going to see about getting one other quote but also tempted to tackle this myself.

 

[dormermike]

Bit concerned about that Circumferential crack in the WC drain at around 2 minutes into the survey, does seem to be a lot of water getting in there. Appreciate the gulley and associated drain is in poor condition, but a gulley is only taking water when an appliance draining to the gulley is discharged. That water has to be coming from somewhere.

Drains need to be fixed, but it could also raise the question of a leaking water service pipe. Judging by the drainage, the age of the property would indicate a lead water service, (and even if the original has been replaced there's no guarantee the old service was disconnected before being abandoned.....) Think without digging it up to see whats going on and the amount of water involved then it's difficult to say further, but certainly wont be the first time an old lead service has been merrily leaking away for many years!

Funnily enough, as the job is currently in progress we have discovered the following:

- the soil pipe vertical drop was indeed inside the house, broken, and leaking
- the gulley clay pot and pipework were wrecked in several places
- alongside the soil pipe is the original lead incoming water main which disappeared right underneath the house. The old gas incomer was also found too, which disppears underneat the bathroom.

I suspect the lead pipe has been capped off in the hallway as the original plans show that a small cupboard was next to the bathroom of the original bungalow. This area has a small amount of damp in it.

The waste pipes very obviously needed replacing, but the builder is unwilling to cut into the lead pipe (which should be dead..) and frankly i don't blame him, i donly said it in jest.

Is there a way to see if it is live though?

Thanks.

 

[dormermike]

Bit concerned about that Circumferential crack in the WC drain at around 2 minutes into the survey, does seem to be a lot of water getting in there. Appreciate the gulley and associated drain is in poor condition, but a gulley is only taking water when an appliance draining to the gulley is discharged. That water has to be coming from somewhere.

Drains need to be fixed, but it could also raise the question of a leaking water service pipe. Judging by the drainage, the age of the property would indicate a lead water service, (and even if the original has been replaced there's no guarantee the old service was disconnected before being abandoned.....) Think without digging it up to see whats going on and the amount of water involved then it's difficult to say further, but certainly wont be the first time an old lead service has been merrily leaking away for many years!

Funnily enough, as the job is currently in progress and about 2 feet of foundations have been excavated, we have discovered the following:

- the soil pipe vertical drop was indeed inside the house, broken, and leaking
- the gulley clay pot and pipework were wrecked in several places
- alongside the soil pipe is the original lead incoming water main which disappeared right underneath the house. The old gas incomer was also found too, which disppears underneat the bathroom.

I suspect the lead pipe has been capped off in the hallway as the original plans show that a small cupboard was next to the bathroom of the original bungalow. This area has a small amount of damp in it.

The waste pipes/drainage very obviously needed replacing, but the builder is unwilling to cut into the lead pipe (which should be dead..) and frankly i don't blame him, i donly said it in jest.

Is there a way to see if it is live though?

Thanks.

 

[dormermike]

oops sorry - sent two messages by accident and doesn't seem to be a way to delete one.

 

[dormermike]

Fingers crossed then there is no old lead services merrily leaking away. I would expect the water to be running constantly if such a leak was present so hopefully it is down the the broken drainage.

Hi Hugh, as i mentioned in a prior post the excavation did uncover a lead water pipe heading off in the direction of the damp issue which was actually line of sight and about 2m from this area here:

Untitled

• dormermike
• 24 Feb 2012
• 3

This little patch was once a cupboard according to the plans and underneath the carpet in a area of concrete which was put down in 1994 when the new plastic water main was installed.

The damp is generally improving since having the soil pipe and drainage repairs done last week, but this area is still showing a little damp (its an internal wall) but i'm hopeful it will continue to improve.

If it doesn't improve after a few weeks, i'm going to lift the concrete, as I wonder if the lead incoming main is terminated beneath here.

 

[Hugh Jaleak]

There is an awful possibility that lead main is terminated under the floor by the usual method of bashing the end flat and turning it over 180 degrees.... Found rather a lot of water under a concrete floor once before, after digging up the area that was formerly an outside WC the source was located, old lead supply for the WC having been terminated as above. Goodness only knows how many years that had been leaking, it had a lump of limescale the size of a football that had built up around it.......

Maybe easier to locate and cap the pipe outside the building, it would be worth doing to prevent any possibility of a future problem, even if the wall is still drying out at present following the leaking drainage. If outside then job is somewhat easier, assuming pipe is still live, bash the lead flat to reduce pressure leaving sufficient pipe to be able to cut and attach a suitable leadloc and cap to seal completely.

 

[dormermike]

Good idea about doing it outside, keep wife happier too !

Will dig up front garden for a look.

Cheers!

 

[dormermike]

Oddly following the inspection chamber dig out and excavation the damp got markedly better but gradually after about 2 weeks it started coming back and is now back with a vengance. Almost as if its filled back up under the slab.

Havent had chance to locate the pipe yet but am in the process of blocking up external vents as they may be letting water into cavity (they are cavity vents only).