The Brew Cabin

Hi - I have a basic guttering question. After cleaning out my gutters this weekend (as a result of water pouring over the centre of a run of guttering when it rains) I have discovered that one of the downpipes is blocked. I have pulled a load of leaves and gunk out of the top 3" (as far as my fingers will go),
but think that the whole length of the downpipe is blocked. The downpipe goes into the ground into a soakaway, my question is - can I cut off the bottom 6" of downpipe (2.5" x 2.5" black plastic pipe) which will allow me to force all the gunk out of the bottom of the pipe from the top. I could then fit a 90 degree elbow to direct the water into a flower bed - OR - should I replace the whole length of downpipe, if so, how deep would I need to dig to enable the pipe to be removed ? and is there any special preparation I need to do to the soil before burying the new downpipe ?? - great site by the way, will definitely be returning for info when I lay my drive later this year.

Tony

Hi Tony,

I'd be tempted to saw through the downspout 100-150mm or so above ground level just to see if the downspout is blocked solid or whether it's just blocked at the top end, where the gutter hopper is. Then, if it's not as bad as you think, the downspout can be jointed back together with a coupling (if you can find one for that range of above ground pipework) once you've cleared the obstruction. Alternatively, use a shoe and discharge into a Hopper or Gully (see below)

However, if the blockage is below ground, causing the detritus to back-up, then you're going to have to dig down and follow the pipework until you find the cause and then fix that according to what you find. If it's just silting-up through years of use, you may be better off replacing the entire pipe run rather than trying to salvage what's there. If it's a broken/collapsed pipe, you might be able to repair. If the soakaway itself is choked.....uh-oh! Time to start again. :(

Whatever the cause, you might as well take preventative measures to avoid this happening again in a few years time. Fit a litter trap into the hopper of the guttering to keep out leaves and mosses. Consider fitting a P-trap and hopper or a yard gully at the foot of the downspout to act as a catch-pit for any bulky crap before it gets to the soakaway, rather than piping straight through, and, if you do end up having to re-pipe the drain, incorporate a rodding eye or access chamber so you can get at the underground pipes without having to dig everything up.

I can't tell you how deep the soakaway will be, or how far the downspout will travel beneath ground level before it meets the drainage system, as each situation is unique and there are no set standards. I can tell you though, that discharging onto a flower bed is a very, very last resort. If the roof area being drained is greater than 10m2, I wouldn't even consider it unless the house was built on sand/gravel and know to have excellent groundwater drainage.

Let me know what you find.

Tony,

Thanks for the comprehensive reply - I was getting myself pumped in the week to start hacking through the downpipe, when I spoke to the maintenance guy at work over lunch about my weekend job. He said that all the private work he had done on problems with blocked gutters had been caused by a blocked downpipe right at the very top of the downpipe (the bit directly under the gutter that goes vertical then 45 degrees in towards the wall then vertical again to align with the downpipe). He said that these are a push fit so should be easy to disassemble once the gutter is unclipped from the supports and the downpipe to wall brackets are loosened. So I did this and to my relief found that the short angled section that I had removed was solid with hard dark brown gunge, leaves and the skeleton of a small mammal, and that shining a torch down the downpipe revealed that it was clear. After a 1/2 hour soak in hot water, the gunge was flushed out no problem. So it looks like I'm sorted !
- while I was up there I fitted litter traps to the openings on both downpipes (front & rear of the house) so should not get the same problem in the future.

Thanks again for the advice, I hope it rains hard soon to make sure that was the problem .

Tony

Good to hear you got it sorted, Tony. :)