It started out as a simple blocked gully, then it was a silted and blocked soakaway and now it's a cracked foul drain as well.
In digging up a concrete path to expose the surface water drain that goes to a soakaway, I discovered that a separate (but nearby) foul drain is leaking.
I need some advice about how best to fix it. I've attached some photos (hope the links work OK!) rather than trying to describe what's going on.
The main leak is just at the collar of the 90 degree clay bend where the cast-iron downpipe enters it. I think it had been cracked in a minor way for a while, but wasn't leaking much because it was encased in the concrete of the path. In breaking the path away, I've just made it a lot worse.
There's also a couple of hairline cracks around the flange of the join that's in the middle of the main picture showing the downpipe, the manhole and the interconnecting pipe. It's not clear whether or not these cracks are actually leaking.
What's the best way to fix this?
As I see it, there are a number of choices:-
Presumably I could cut out the damaged area of pipe and repair the breaks using one of those flexible (rubber?) joints that are clamped to the pipe using stainless steel jubilee clips.
I'm a bit concerned about taking this approach because the joint between the clay and the cast-iron downpipe is above ground, so will be visible. The second concern is that, although this drain is close to the house, it's actually under a driveway, so technically could be driven over. Also, the drain is only about 150 mm below the surface. That sounds too shallow to be able to withstand the weight of a vehicle, even relatively infrequently.
I could also replace most of the pipe, but use a flexible joint so that I don't have to break into the benching in the manhole itself. If I go for replacement presumably I could use plastic or clay.
I could also replace the whole downpipe, but I don't really want to do that right now because it will affect the bathroom decor. I'd rather keep this as an 'outside only' job if I can.
So, given factors like a cast-iron downpipe (4.5 inch external diameter) and clay underground (approx 5.25 inch external diameter), the need for a connection between the cast iron and clay above ground, the shallow depth of soil cover, it's driveway location, etc, what's the best way to fix this?
Are there rigid fittings available that enable joints to be made between cast-iron and clay or plastic without having to resort to flexible connectors and jubilee clips?
Given the minimal depth of soil coverage, should I be protecting the pipe? If so, how's the best way to do it?
Any guidance and advice would be most welcome.
Thanks,
Mike
[Edit] I've just noticed that I've been promoted from 'apprentice' to 'digger'. Most appropriate, under the circumstances
Renew in plastic because it is easier to cut/play with and it won`t break when you drop it.
You are right about using flexi/band seal couplings above ground, you need a solid plastic adaptor.
Off the top of my head a plastic to modern clay adaptor is a AD400 special, a plastic to older thicker walled clay is a AD400, (at TP that is). You will need to mix and match as cast iron pipe sizes vary so much.
A properly bedded pipe will withstand vehicular movement but you could always encase in concrete if required.
you need 1ac400 adaptor for clay to plastic,the cast iron is thinner than you think and 1 plastic to cast
and a rest bend and about 1 m of 110 mm platsic orange pipe
LLL
Gonna display my ignorance now... Which manufacturer do those ac400/ad400 part numbers relate to?
Is there any one manufacturer who has the best range of drainage fittings and adapters, or are they all much the same? I know my nearest builders merchant does Hepworth stuff, but I haven't had to do much drainage work before, so I'm not familiar with what's available.
I'm still a bit unclear about the ability of plastic to withstand the rigours of being under a driveway. Given that there is literally only 150mm of soil coverage, and the top surface is just small chippings - not paved - is it OK to use plastic at that depth?
Now that I've cut out the old pipework and cleaned-up the end of the cast-iron downpipe I've found that the levels work such that I would need to cut back a few centimetres of the cast-iron in order to be able to use a 110mm plastic rest bend. This would mean that 15-20 centimetres of the rest bend would be exposed above ground. On the other hand, if I were to use a short bend instead little, if any, of it would be above the ground. All that would be seen would be the black Hepsleve cast iron to 110mm adapter.
Two questions, then.
First, is there any reason why I shouldn't use a short bend instead of a rest bend? The original clay fitting provided a very tight bend - nothing like the profile of a rest bend. As a short bend doesn't have a 'rest' fitting, I presume I'd have to set it in a bed of concrete to keep it in the right position.
Second, I already have a couple of these fittings available in the usual brown plastic. If some of the brown fitting shows above ground, can it be painted without risk to the integrity of the plastic or the (neoprene?) seal? If they can be painted, can any normal exterior paint be used, or are there any paint types that must be avoided?
You could try a different pipe manufacturer, the radius of rest the bend is not a fixed/specified thing, it is only the fact that it has some legs for support (and bedded on concrete) that is required for building regs.
