Gutter issues

FuzzyGirly

Hi all. Just want some advice. Last summer, I took part of my downpipe out to clear some blockage but there was none. However, when it's heavy rain the downpipe overflows at the top as the surface water can't drain too quickly and will cause water to flow down the house wall. I have a Waterbutt connected to the downpipe and it is full as well. The downpipe connects underground and there is a bend so I'm not sure if I need to slowly put a drain rod through to see if it is clogged? I have standard drain rods so perhaps not as bendy as they should be.

Any advice much appreciated as my walls have water marks since this issue has been persistent over the last 2 years if I actually need to call a professional to investigate any ideas how much damage this would be?! Thanks in advance.

FreeBear

Do you know where the underground drain pipe goes to ?

It could well be clogged, so a super bendy drain rod may help to clear it. Failing that, a pressure washer with a drain cleaning nozzle might do it.

Jeepers_Creepers

Wow - that's really blocked!

If you are certain that the downpipe itself is clean - and you seem to be - then obviously the blockage is somewhere underground. This will either be feeding into a sewer (which is generally dependent on property age but is no longer permitted)  or else feeding into a soakaway, which is a hole in the ground filled with rubble.

For the former, there's clearly a blockage somewhere so you'll need to locate an inspection manhole or else get some rods in there somehow, and for the latter it could be the same issue, or simply that the soakaway has become filled with sediment and can not longer soak-away. These can be back-washed, I understand, but I know nothing about this.

Could you add a photo showing the downpipe at the ground level? Are there any other drains around that area?

grumbler

FuzzyGirly said:

 The downpipe connects underground and there is a bend so I'm not sure if I need to slowly put a drain rod through to see if it is clogged?

If it's a P-trap like this, you can try cleaning the bottom with your bare hand

twopenny

How carefully have you checked the area where the waterbutt is connected?

There must be a slight incursion into the pipe and it's possible that some of the crud off the roof is accumulating there during heavy downpours.

And the last two years have been unremittingly wet.

FuzzyGirly

Thanks to all who have responded for your helpful feedback. I attach a few more photos. So last year I removed the connector pipe to the water butt and the downpipe was clean up to the point where you can see it, and then it bends underground. At that time, I wasn't sure if I was able to lift the patio slabs to investigate further. I wonder how easy it is to access the P trap without much tools if there is indeed one underneath...
 

FreeBear

Downpipes disappearing in to the ground like that is bad news. Any blockage, and you have to go lifting slabs and start digging unless there is a rodding eye close by.

As it looks like you'll be lifting slabs and digging, I'd strongly recommend fitting one of these - https://www.screwfix.com/p/floplast-d94-debris-gully/25121 - You may need to lift several of those slabs in order to modify the underground pipework (watch your back, they will be heavy).  Once fitted, the trap will intercept much of the debris likely to cause a blockage.

If the downpipe goes to a soakaway, there probably won't be a P trap underground - Most of the time, a basic 90° bend is fitted. Same if you are discharging to a watercourse.

Only time a P trap is used is when connecting to a foul water sewer (and yes, you can still discharge rain water into a sewer legally as a last resort).