Need to clear blocked downpipe

[iburnell]

I am trying to replace old cast-iron downpipe with plastic. It is concreted in the ground but I found it lifted out from the lower bracket leaving about 12-15" above ground. What's left is completely full of gunk - earth and rusted iron. I have removed out what I can to ground level but it is still not clear. How do I know whether this exhausts out into the main drainage system which is close by or just goes to a soakaway - I read some articles saying that downpipes should never be put into the mains drain??. I had a plumber round and he said you'd need to get a drainage company to look at it - which costs a fortune. Is there anyway I can hire something to clear it out myself ?

Thanks

 

[footprints]

Might be worth trying a wet & dry vac if you have one, to see if you can get any further.

 

[Hugh Jaleak]

Age of property is usually a clue, anything built prior to the 1960's often has a combined system of drainage, whereby all sewage and rainwater goes into the same drain and finds it's way to the works for treatment. After that separate systems were introduced whereas foul water goes for treatment, surface water from paved areas and roofs drains into a storm sewer which often discharges into a watercourse or soakaway.

Possible to hire a pressure washer with drain clearing attachment (messy!), try shoving a hosepipe down to loosen up and wash out any muck, but if pipe is pretty badly blocked underground, professional help (or excavate and replace) may be only option. Unless you can get some water through it (and possibly dye test) it'll be virtually impossible to ascertain where it goes.

 

[iburnell]

Thanks Hugh - house was built in 1956 I believe. As I said it is very close to the main drainage from kitchen so I had always assumed it just fed into it. I do suspect the sewage also joins into it since the toilet downpipe is also on the same side of the house

 

[Hugh Jaleak]

Quite possible, unfortunately there's no hard and fast rule how rainwater was connected. Could be direct to drain (although not ideal), could be to a soakaway or could even be a gulley pot buried under the concrete. Found a buried pot under some paving slabs that had been down since year dot the other week..... Cleared umpteen years worth of debris out and it flowed away like a good un.

 

[iburnell]

Just to update this I had another go at this today - scrapped out as much earth as I could and then used a long stick to push down - I was surprised to see it go down at least another 2 foot below the ground - I then poured about 1/2 gallon water from watering can and I could hear it gurgling like going down a drain - but it all disappeared ok - retired this about 3 times so I'd says its all clear to go !