Surface water drain - Blocked?

[rubble2]

Hi,

We have a large semi about 100 years old, one of the drainpipes from the roof gutter is at the boundary of the two housess and takes water from the roof valleys of both properties.

I have noticed a small damp patch on the wall behind where the drain pipe runs and decided to investigate. The down pipe is plastic and undamaged but I found that the gully that the pipe runs into was completely blocked with soil and stones etc.

Dug as much out as I could get to and am now left with standing water in the gully which is still very slow to drain.

I tried to find where the drain ends up and it appears that the pipe runs under the garden at the boundary (under a 6ft hedge) and appears as an open 100mm pipe in the garden wall which then runs across the pavement via an open channel and hence into the road gutter.

I have tried filling the gully with water and as I said it drains out slowly but no water appears at the open pipe by the roadside, could it be designed this way as some sort of soakaway with the pipe there to handle excess water when required?

If not, then does this look like a blockage in the pipe run under the hedge and if so, what is the best way to clear it (rods?).

Also, is it still possible to get 8inch gully grates (round) no one seems to stock them locally.

Thanks

 

[Nick98]

Hmmm - do you get anything out of the pipe beyond the hedge to give you some confidence that the two are connected?

If not then either there is another pipe (the two pipes are separate things) - or you have a major breech in the pipe run. I know that sounds obvious but I have had friends who have spend hours digging to find out why something wasn't draining to find they were digging up a different pipe - admittedly that was on a farm but same principles apply!!

If there is a trickle then again either a breech or a blockage as you suspect. I would think though more of a blockage as the water is backing up in the pipe and coming out of the joint as you describe. With a breech or fracture it wouldn't back up but would instead drain away en-route without ever exiting the pipe beyond the hedge.

Talking of hedges when you say the pipe under the hedge is 4" is it a clay/saltglaze pipe or plastic? If salt glaze then I would start at the tree end as the roots may have fractured the pipe. You will get some idea by trying some drain rods from the outlet back up the pipe, if there are roots, or a fracture then you will feel it as a minimum. You will be able to work out where the break/blockage is from how many rods you put into the pipe.

As for a solution then you could get someone in to jet it as that often will cut the roots and unblock it (on the assumption the roots are that well established). Try and go by recommendation and not just pick a number out of the local directory as that can prove expensive and there are some cowboys about!

Either way that is really only a temporary solution as the roots will grow back again. The only real long term cure being to replace with plastic. To save cost you could just replace the fractured/breached section in plastic but assuming its not miles of digging and is accessible (no drives/paths/foundations in the way) it would be much better to dig out the clay and renew in plastic back to the downpipe on your house That will give you a few years of trouble free drainage.

A nuisance I know but better that you fix it rather that having water either spewing out down the side of the house leading to damp problems, or it seeping away underground possibly causing further damage that you don't know about.

Good luck and let us know how you get on.

 

[rubble2]

It requires further investigation but at the moment nothing appears to flow out of the pipe.

I am pretty certain that the pipe is connected to the problem gully as they are in a direct line with each other.

The hedge is the dividing border between the two properties and it runs directly above the pipe for the full length of the front garden from the gully to the front garden wall so there is plenty of opportunity for the roots to have broken through (pipe is clay).

Because it appears to be such a straight run, I think it would be worth trying some rods just to see if there is any obvious blockage, I dont fancy digging the pipe up as it would entail uprooting the full 20 foot length of hedge to get to it.