Drainage

Hi all,

Not strictly on topic, but I'm hoping some of the experience here might shed some light on a drainage problem.

3 drains in the back yard used to be fine but now back up and overflow whenever we get a halfway decent rainfall. They feed into a common run that goes underneath a concrete slab and there are no plant roots in the vicinity that could be blocking them, and the problem seems to have started sometime after some work was done for a pergola. I suspect that either some cement has found its way into the drain, or it is simply blocked by dried mud after the long dry spells.

So called "experts" are saying it is insufficient fall, collapsed pipes, and other things that involve enough work to rebuild the pyramids. This just doesn't make any sense to me as they worked fine at one time. and the slab is still sound. If it is simply as I suspect, what's the best way to clear them, or at least eliminate the cheaper solutions before spending the superannuation on fixing the problem. I've tried a hose which seemed to alleviate the problem for a time but I can't get it down far enough to really clear it and now its back again.

Any ideas would be most welcome.

You could get one of those guys in with the cctv camera - then at least you know what you are delaing with.
Not sure if you can rent them......

Of buy an extension to your hose....
Geoff

Quote:

---

Originally Posted by normc

Hi all,

Not strictly on topic, but I'm hoping some of the experience here might shed some light on a drainage problem.

3 drains in the back yard used to be fine but now back up and overflow whenever we get a halfway decent rainfall. They feed into a common run that goes underneath a concrete slab and there are no plant roots in the vicinity that could be blocking them, and the problem seems to have started sometime after some work was done for a pergola. I suspect that either some cement has found its way into the drain, or it is simply blocked by dried mud after the long dry spells.

So called "experts" are saying it is insufficient fall, collapsed pipes, and other things that involve enough work to rebuild the pyramids. This just doesn't make any sense to me as they worked fine at one time. and the slab is still sound. If it is simply as I suspect, what's the best way to clear them, or at least eliminate the cheaper solutions before spending the superannuation on fixing the problem. I've tried a hose which seemed to alleviate the problem for a time but I can't get it down far enough to really clear it and now its back again.

Any ideas would be most welcome.

---

Quote:

---

Originally Posted by normc

Hi all,

Not strictly on topic, but I'm hoping some of the experience here might shed some light on a drainage problem.

3 drains in the back yard used to be fine but now back up and overflow whenever we get a halfway decent rainfall. They feed into a common run that goes underneath a concrete slab and there are no plant roots in the vicinity that could be blocking them, and the problem seems to have started sometime after some work was done for a pergola. I suspect that either some cement has found its way into the drain, or it is simply blocked by dried mud after the long dry spells.

So called "experts" are saying it is insufficient fall, collapsed pipes, and other things that involve enough work to rebuild the pyramids. This just doesn't make any sense to me as they worked fine at one time. and the slab is still sound. If it is simply as I suspect, what's the best way to clear them, or at least eliminate the cheaper solutions before spending the superannuation on fixing the problem. I've tried a hose which seemed to alleviate the problem for a time but I can't get it down far enough to really clear it and now its back again.

Any ideas would be most welcome.

---

Have you thought about hiring a snake to do the job? It sounds like a buildup of sediment to me.

I did enquire about hiring a snake and even they're fairly expensive. Something like $140/half day & $180 for full day. I've never even seen one used so I don't know how long I'd need it, how to use it, the possibility of damage without any experience, etc. Typically, the hire company was pretty unhelpful with most questions, as they are these days. From memory, they also use their own motor and need a trailer to transport, which we don't have.
If I had the confidence that it would solve the problem. we'd probably go ahead but without using one and knowing how well they work, I'm a little dubious.
Norm

Most snakes I've seen are electric and would comfortably fit in the back of a ute or even a biggish boot. I've not used one either, but the principle is pretty simple and I don't think they'd be too harsh on your pipe, but others might disagree so don't take that as gospel.

Get a longer hose. Sounds like something is partially obstructing it and crap is building up over time and blocking it. Get one of those male to male connectors and borrow your neighbours hose and shove it down there and give it a blast. You might find it gets to a point and will go no further. At least then you'll know what the problem is.

Where does the pipe under the slab discharge to?
How far is this point from the slab?
Does water ever come out of here?
Was the pergola work anywhere near the drain?

If you can easily access the end of the pipe in a fairly straight line I would be hiring a snake and feeding it up and see what happens. I think the prices you have been quoted are high so if possible try somewhere else. Kennards have them for $68 for 4 hours. They will fit into the back of a wagon or ute or maybe the boot of a largish car.
They have instructions on their web site www.kennards.com.au and even if you do not hire from them, at least that will give you some clues.

Jon

Already tried the hose thing but it goes so far and no further. Problem is, this could just be a right angle bend or a T junction in the pipes. No way of knowing.
Kennards just informed me that electric eels are no good for plastic drainage pipes as the cutters will cut through the plastic very easily. They are for clay pipes apparently. The place is only about 6 yo so the pipes are most likely plastic I would think.

Norm
Most plumbers have or have axcess to a snake
Check them out on a price , ie one day on the way home etc

Sounds a bit suss if it only started after work on a pergola, was this built over the drain, was there any chance some off cuts could have entered the drain
Can you axcess the drain just before it goes under the slab and where it comes out as you need to locate the blockage point , As silent c says get a longer hose etc and try from both ends if you can.
As the drain is pvc if you can axcess it you can cut a hole with a hole saw to inspect then glue a patch over the hole



Rgds


Ashore

Thanks a lot, Jon thats useful info. Any thoughts on the plastic pipes? Kennards also mentioned that licensed drainers use special gear for plastic pipes thats not available for hire.

We had this drainage problem in a rented house once. We had a downpour and it flooded the yard. I searched around for a drain and I found a 50mm pipe poking out from under the garage wall. I grabbed the garden hose and poked it into the pipe. A short way in, it stopped, so I shoved it a bit harder and turned on the tap. A small rubber ball about the size of a ping pong ball came out. One of the kids had put it down there.

Cost: $0. My point: try and clear it with the hose before wasting your money on something you might not need. If you can't dislodge it with the hose, then go hire the snake. From your description, it sounds as though something is stuck down there and when you shoved the hose in, you either cleared it or pushed it further down.

A hose connector will cost you a couple of dollars.

You need to try and access it from the other side. That's what I did. If there's something in there, it might be stuck in a bend. You want to try and blast it out the way it came.

Know the feeling silent , put the hose from the road drain end and got a nerf ball , 4" diam foam rubber, then put a grill over the drain.


Ashore

if you can only poke the hose in so far, mark how far this is on the hose and then lay it out on the ground and see how far you are and what may have caused a problem in that area.

Do you have any idea where the pipes may run and would you expect a 90deg bend?
I have used an eel on plastic pipes but was I fairly sure on which way the pipes were running and knew there was not a sharp enough bend that would cause the eel to dig out through the wall of the pipe.

If you jam the hose in (real hard) till it stops and then pull it out without turning the water on does it come out clean, muddy, wet or dry? The answer might help in working out what sort of obstruction you have got.

I should add that I have no proffesional experience but I am haunted by dodgy drains.

Jon

I couldn't get a plumber to use an eel on plastic pipe - they do have a habit to damage it.... having said that a mate of mine used one a couple of weeks ago and it seems to be fine.
The stuff they use is a high pressure water cleaner - the head has fine jets that cut through tree roots etc and is less damaging on PVC pipe. Never seen anyplace that hire these.

Geoff

Guys, Thanks for your help and suggestions. To answer some of the questions; The drain goes out into the gutter at a point about 10M from the edge of the slab, but very little discharge at present. The inlets are all just a metre or so from the slab. Tried the hose but it may be a little too soft & flexible and in need of a jet nozzle on the end. Problem is that prevents it from going round bends. The pergola work was nearby and in fact some mods were made to one of the drain inlets to accomodate the downpipe from the roof. I suspect some sloppy workmanship may be at least part of the cause, but if it is hardened cement it won't be easy to clear.

have you tried putting the hose in from the gutter end as well as the each and every drain?
It does sound like the problem is in the "main line". Would the pergola connection be the most downstream connection?

Actually, thats a good thought Jon. The pergola connection is the most upstream connection (wish we could draw diagrams here) which would indicate it is more likely a general build up of sediment than hardened cement. Would you agree?

If you can manage to get hold of a strip of yellow tongue (from yellow tongue chipboard flooring) it's a bit stiffer then a hose but still a wee bit flexible. It might help to illuminate if not eliminate the source of the blockage. If you get it to where the hose stops, jiggle it around a bit and pull it out you ma be able to determine whether the end is roughened like it's hit concrete, or even with a splinter in it.

Because of its dimensions, the flexi side of yellow tongue will allow it to go around a reasonable corner, but the stiff side won't. The stuff is also great for pulling cables through houses - that's how I found out about it, my electrician showed me and I've found marvellous uses for it ever since. Tapping the Mrs on the shoulder from 3.6 meters away over a fence and scaring her silly was a highlight.:eek:

I wouldn't be surprised if you found the pipe blocked by an off cut or a soft drink can etc from the pergola. You wouldn't believe the lengths necessary to try to stop people/workers/kids putting things down drain pipes because they're too lazy to put something in a bin or worse. Not long after moving into a new house a few years ago we eventually found the raw sewerage cascading from a vent over the beautiful turf I had laid a week earlier to be caused by a drink can. Did I mention the Mrs was preggers with our first at the time and paranoid she and the bub would contract hepatitus A, B, C and G plus AIDS and haemorrhoids etc etc and made my life an absolute mysery until it was fixed? - I s'pose she was right tho' somehow it MUST have been my fault. :D

Good luck with the investigation.

Normc,
Why don't you use paint or something similar to draw a simple diagram and then upload it as an attachment - use the paperclip icon on the message creation pallet.

Geoff