How to Check and Maintain your Guttering or Rainwater System

The best possible time to check your rainwater gutters and down pipes is….. drum roll please….

When it’s raining!

rainbowI know, crazy huh? But believe me when I say that nothing beats a proper ‘wet’ check of your rainwater system. You can look at your gutters all you like on a sunny day, but if you don your waterproofs and head outside after it’s been raining solidly for a couple of hours you’ll learn tons more.

Ignore the funny looks from your neighbours, tell them you’ve lost your goldfish or checking to see if your hat leaks. No, only joking; tell them you’re checking to make sure all the rainwater is going where it’s supposed to go, and that there are no leaks from joints in the guttering or downpipes unnecessarily wetting the wall. Tell them you’ll check theirs too… for a small fee of course (only joking, it’d be a big fee, think of all the money they’ll save not having to repair the water damage!).

But seriously though, the most important thing is for you get out there and take a good look whilst it’s actually raining. Properly raining, the harder the better. Think about it, if you take your car to the mechanic and say there’s a problem with the engine, the first thing he’s going to say is “lets hear it running then”. Yes? It’s exactly the same with your guttering and downpipes, you need to see them RUNNING!

There is only one problem, you’re going to get wet and wet can mean slippery. Now hopefully, most places you can see your guttering from the ground, so you just need the right clothes to keep you dry for a few minutes outside in the rain. However, if you suspect a gutter is not doing it’s job properly, you might need to get up close to see exactly what’s happening. And ladders and rain don’t really get along, so you’re going to need to plan ahead.

eye-bolts-webKeep an eye on the weather forecast and a day or two before a big rain is forecast, go to where you want to put up a ladder and install a permanent eye bolt high up and very securely tie the ladder to it. Make sure the foot of the ladder is secure and stable too; I like a bag of sand either over the first rung or laid across the foot. If you’re on grass/soil/gravel stamp on the first rung a little and get the foot of the ladder well rooted.

If the forecast is right and it starts to rain, wait until it’s really been going at it for a while (it takes a little time for everything to start running). Then don your waterproofs, plus a pair of good non/slippery boots and head outside. Take a walk around and have a really good look at each section of guttering and each downpipe.

Be super careful if using a ladder, BIG TIP: Only move one hand or one foot at a time when climbing ladders, (like mountain climbers do), then you’ll always have 3 limbs safe at any point). ***Warning, this advice might save your life*** (You’re welcome!)

Especially look out for…

  • Water overflowing the front edge of the gutter like a waterfall.
  • Water overflowing the back edge of the guttering and running down the wall.
  • Water overflowing at the end of the guttering.
  • Water overflowing at the downpipe outlet.
  • Water dripping from joints in the guttering lengths.
  • Water leaking from the downpipe joints.
  • Water pooling around the base of the downpipe.

Maybe you can tie in your annual guttering check with SPAB’s (The Society for the Protection of Ancient Buildings) National Guttering Day, which is a part of their campaign to get homeowners more involved in the maintenance of their homes. read more here…

How to Fix a Problem with Guttering

If you spot a problem with the guttering, the first thing to check for is blockages. Water might be overflowing a perfectly good guttering system because the water cannot get away quick enough.


  • The guttering itself might be full of moss, leaves or pine needles etc. (very, very common).
  • The downpipe might be full of debris that’s been washed down over the years, especially in any bends at the bottom (quite common in older properties).
  • If there is a gully or trap at the foot of the downpipe it might be full of debris (very common).
  • It’s also possible for soakaways to become full or silted up and need digging out (quite rare).

If nothing looks blocked, then you’ll need to look at how well the system has been installed to find the problem. Lets go through a few of the more common problems…

(NOTE: the following advice relates mostly to the sectional plastic or cast iron systems common in low snow level countries like the UK.)

Check the guttering is not too far down from the roofing material allowing rainwater to overshoot. If repositioning start at the highest point of the run just underneath the bottom edge of the roofing material. Don’t push the gutter right up around the overhanging roofing material as this limits access for future cleaning.


Also check  that the roofing material is overhanging the guttering properly. If the overhang into the gutter is too much, rainwater will end up overshooting the gutter, too little and it could run behind the gutter. If repositioning your guttering,  aim for the roofing material to project over the gutter width by about a third and no more than half way, or you’ll struggle to get into the gutter to clean it out. Put spacers behind the brackets or double up part of the fascia board if the roofing material overhangs too far.


Although not technically part of the guttering, the roofing material needs to be in good shape too, broken tiles can cause water to pool around the bottom of the roof/ guttering area causing extensive damage. Ideally, the roofs properly supported membrane/system should run into the gutter.

Check the guttering has a slight run, fall or slope towards the outlet. Technically, a perfectly level guttering system will work as the lowest point is the outlet. But in practice you’ll find a slight fall is better, because  it can cope with a larger water flow, plus it drains quicker, there’ll be less water sitting/ freezing in the joints, it will also leave less sediment to build up in the bottom.

If you need to reposition the guttering, aim for a fall about 1mm per 300mm (you can go a little more or a little less depending on the room you have). Fix the highest bracket first followed by the outlet, the correct distance down to create the right fall and then use a tight string line between the two to show you exactly where the other brackets go . Be careful to position each bracket a hairs breadth underneath the string line and ‘pling’ the line after each bracket to ensure it’s still ‘free’ and thus accurate. If the pling stops suddenly it means a bracket is touching it and pushing it out of line…

Dripping gutter joints are extremely common and can usually be rectified by replacing the rubber seals on most sectional plastic systems. Unclip the joints and remove if possible. Clean very thoroughly (they’ll be gritty or slimy depending on the gutter location) and replace the seals with new ones. On obsolete systems you’ll have to re-use the old cleaned up seals and add a quality sealant as well. Success varies with this repair as guttering moves around a lot from thermal expansion and contraction which can ‘unstick’ sealant. Still it’s worth a try if you can get everything clean and dry enough. Gutters are supposed to move around a little and joints installed properly allow for this. If the gutter ends are touching each other in a joint, buckling is likely (there should be a small gap).

Similarly, repair cast iron guttering leaks by cutting off (it will be rusty, trust me!) the connecting bolt and gently separating the joint (start at the top edge, very gradually tapping a slim implement a tiny way into the joint and remove, repeat a little further around and work around the joint; NB, cast iron cracks extremely easily).  Very gently prop the guttering joint apart with a small block of wood to create working room, supporting any other stressed joints on timber wedges inserted between the brackets and underneath of the gutter. Clean out the old putty from all parts and preferably repaint before re-sealing with a low modulus silicone sealant. Gently tighten a new stainless guttering nut and bolt and wipe away any excess sealant inside and out.

Also check there are enough downpipes. Long runs of guttering might struggle to empty before the far end becomes full and overflows. Consider ‘breaking’ up long runs to two or more downpipes. An additional downpipe is also a possible solution for sections of guttering that overflow because the building has settled creating a ‘low spot’. It’s better for the water to run into the garden than down the wall…

Downpipes shouldn’t leak as they are installed ‘one into the other’ or ‘male into female’ (don’t you hate that expression these days?) always following the same direction (so check for this). No seals are usually necessary. Leaks are often caused by a blockage or a cracked pipe.

If your downpipes don’t go straight into the ground /pipe, ensure the water spilling out from the bottom of the pipe or shoe is all going into the grate and not spilling around the edges as this will erode the surrounding area and find its way into the wall. Most grates need a brick or concrete surround with raised edges to achieve this.

B&Q have an extensive range of guttering systems including square line, half round, mini-flow and hi-capacity ranges, plus of course all the accessories you’ll need to install and maintain them. Check out B&Q’s guttering and drainage stuff here

Ok, that cover the main culprits, but feel free to let me know if I’ve missed one you’ve experienced. 

Stay well


p.s. sorry this turned out so long, the tip I originally want to say to you was “go and check your guttering when it’s pouring down with rain! lol!!

p.p.s. Don’t forget you’ll be helping fund more articles like this is you use the above links as I’ll receive a small commission (at no cost to you) from B&Q, Amazon etc.





Comments 2

  1. I’m so pleased I happened upon this website. Clear and straightforward advice and explanations…brilliant!

    1. Post

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