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Water butts, decking, diverters and overflowing


Another question about water butts I'm afraid!

Our builder has voiced concerns about having the water butt on our decking.  He said that even with a rain diverter, if we have torrential rain the diverter may not stop the water butt overflowing and this of course isn't ideal if the butt is standing on decking.  Can torrential rain really cause this problem with a rain diverter?

On a side note, I've also read that water butt lids should be a tight fit with no gaps, to stop bugs getting in and breeding.  Our water butt has four small holes (designed, not caused by damage) in the lid, all about 5mm wide.  Should I block these with something like silicone sealant?

This water butt feels like it's more hassle than it's worth... 



  • GardenmaidenGardenmaiden Posts: 1,125

    Hi Pariate

    we have three linked water buts down the side of our house and they sit on a deck that is 12 by 2 feet. We have never had any problems with heavy rain and our water buts have never overflowed. We also have two that take the run off from the greenhouse and again have not had problems with overflow.

    The water but lids are tight to stop mossies laying their eggs in. You probably need one of the holes to feed pipe/tubing into. I think ours have holes and we haven't blocked them up.

    I'm guessing the builder could be concerned that your decking may rot where your water but is, if the water doesn't drain away.



  • pariatepariate Posts: 77

    Thank you Gardenmaiden, that's good to know.  The rain diverter will be fitted to a downpipe which will in turn lead to our drain, so I hope that will avoid any problems with the decking. 

    I couldn't see any purpose for the holes in the lid because the hole for the input pipe (leading from the rain diverter) is in the side of the water butt.  Could you tell me what pipes/tubing I might need to feed into the lid please, or were you talking about the input pipe?

    Thanks so much for replying!

  • Singing GardenerSinging Gardener EssexPosts: 1,148

    Hi Pariate

    It may depend what area of roof the downpipe collects from. We have one downpipe for the whole house and the diverter does fail to cope when there is torrential rain but it's quite unusual only to have one so yours may get less rain.

  • BookertooBookertoo Posts: 1,306

    Water butts may overfill and thus overflow, but I've never heard of them causing rotting to decking - the water will just drain away.  We have several butts around the place, some of them there for many years, and all works fine.  They are not more trouble than they are worth once you get used to them, because your plants will love the contents so much more than tap water.  

    I have a jam jar in one of the unused holes in one of mine - from which all the birds like to drink - no matter how many water feeders there are about the garden!  I guess they are there for different types of fittings - I've never thought about it, but off hand cannot think of another purpose for them.

    You can stretch some old socks or tights over the holes to let air in and out but keep the insects and/or mozzies out. 

    We have a waterer diverter, and two butts linked together so that when one fills the other takes over - they're full now but will be essential later on - I hope. 

  • LynLyn DevonPosts: 17,598

    What a fuss your builder is making over this, is he hourly paid!!. maybe he doesn't really know. Did you really need a builder to put a butt in?

    The idea of the diverter is to catch the water in the butt, when its full it automatically goes down the drain pipe. Never had a problem.

    I have 12 various butts around, some are just big dustbins, anything that catches water. Never had a problem, if something has laid eggs in there they have never been a problems to any of my plants.

    Gardening on the wild, windy west side of Dartmoor. 

  • GardenmaidenGardenmaiden Posts: 1,125

    Hi Pariate,

    we've used ordinary garden hose to go from our greenhouse to the water buts.



  • Your decking will be wet or damp for long periods at certain times of year. The occasional heavy storm won't add significantly to this, so don't worry!

  • WelshonionWelshonion Posts: 3,114

    It is called a diverter because it diverts water into the butt, and if it is set up correctly when the butt is full the water is diverted into the downpipe.  This will not affect the decking in any way.

  • pariatepariate Posts: 77

    Singing Gardener - It will only be collecting rain from the guttering around our kitchen extension, so you may well be right!  The main guttering feeds to the downpipe which drains into our neighbour's drain, because this is a mid-terrace house.


    Lyn - The builder is here doing all sorts of work, renovating our 70' garden which, until a month ago, was covered in over a foot of concrete.  He's just altering the guttering to allow us to have the water butt as it won't fit anywhere near the current location of the downpipe.  That's the only reason he's fitting the butt and not us.


    Thank you everyone for your feedback.  I'll try stretching some old tights over the holes as suggested.   We'll just see how it goes, I'm sure if there are any problems we'll realise long before the decking rots away completely. image  All this gardening lark is such new territory to us that even little things leave us wondering if we're making horridly obvious newbie mistakes!

  • WelshonionWelshonion Posts: 3,114

    One newbie mistake is not realising that decking needs a coat of preservative every year.  The suppliers say it has been treated for rot, but they exaggerate!!

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