Results 1 to 7 of 7
  1. #1
    Join Date
    Jul 2005
    Location
    Toowoomba Qld.
    Age
    65
    Posts
    0

    Default drainage from roof

    Hi there,
    Looking at alternatives for where/how to plumb roof water drainage from guttering on the extension. Can't afford a tank which would be the best option, so I really need to plumb the outflow away from the foundations (stumps).
    The problem is the cutting made into the gradient, as this dictates how deep the stormwater pipe is put. The lower end of the cutting is not an option as there are too many other services to contend with. As I see it the possibilities are based around burying the pipe right under the cutting then bringing it up somewhere away in the original contoured ground...which means a section of pipe will always hold water, like an elbow under the sink (pictured).
    Any problems with this? Is it kosher, or should there be some valve or screen to stop mossies etc, or stale water?! Any thoughts welcome.

    Cheers,
    Last edited by Andy Mac; 9th May 2008 at 02:41 PM. Reason: picture
    Andy Mac
    Change is inevitable, growth is optional.

  2. #2
    Join Date
    Aug 2003
    Location
    Pambula
    Age
    59
    Posts
    5,026

    Default

    I don't think there's any problem with it. All of my storm water pipes are permanently full of water (I hope). Mossies can't get in because it's sealed to the tank but there's nothing stopping you putting a flywire vent over the end of it.
    "I don't practice what I preach because I'm not the kind of person I'm preaching to."

  3. #3
    Join Date
    Jan 2007
    Location
    Adelaide - West
    Age
    43
    Posts
    311

    Default

    It's done all the time,

    • Use 100 pvc (heaps tougher) and leave an open junction up high on the d/p to act as an overflow
    • Put an inspection fitting at the lowwest point in the path around the building so you can open it and clean out any muck that might get in there.
    • You should use mozzie wired vent caps at entry and exit (mesh screen)
    • You should seriously consider the use of gutter guard type product for the roof, this will help prevent the inflow of rubbish.
    Do not use the aggregate pit as the water will try to run under ground and will probbably end up back at the footings anyway.

    Cheers

    Any more questions just ask

    Bricks
    If you dont play it, it's not an instrument!

  4. #4
    Join Date
    Nov 2003
    Location
    Australia and France
    Posts
    2,869

    Default

    I know you've said the lower end of the cutting is not an option, but I'd have to see it in plan before I believe you!

    Hopefully you've got enough fall in the cutting to drain surface water away?

    As you have drawn it, you will have two problems in extreme conditions, the gutters will overflow earlier than they would otherwise because of the head that the downpipe has to overcome, and at the same time, when the pit is fully charged, it's on the high side and you'll have to ensure that water doesn't flow back against the house as well. You could also find that you have a spring appearing out of your batter!

    Have you thought of running a simple spoon drain to the ends of the house and disposing of it from there?

    Cheers,

    P

  5. #5
    Join Date
    Jan 2008
    Location
    Brisbane
    Posts
    7

    Default

    Can't afford a tank which would be the best option, so I really need to plumb the outflow away from the foundations (stumps).


    You would still need to install storm water drainage even if you had tanks because when the tanks are full the subsequent water will have to go somewhere.
    If you are not part of the solution then you are the problem

  6. #6
    Join Date
    Jul 2005
    Location
    Toowoomba Qld.
    Age
    65
    Posts
    0

    Default

    Thanks for the replies! I may be on the right track afterall.
    I didn't think of water soaking back through the ground to the cutting/batter, which will be a fairly steep retaining wall on each side. And the whole idea of head to overcome...certainly didn't think of that! All I can say is both gutters run along verandahs, so if they overflow its not a great concern! And I know tanks need an overflow, our small one is so fitted. Would be simpler if there was only the one to consider...
    The low end of the cutting is where the original house is, the new one is 90* to it. There is some fall around the new house, but still some levelling to do, and a small spoon drain to take any buildup away. It will come from under the deck of the breezeway between the houses, I just don't want to overload it with full flow from the gutters.

    Cheers, thanks once again.
    Andy Mac
    Change is inevitable, growth is optional.

  7. #7
    Join Date
    Feb 2003
    Location
    back in Alberta for a while
    Age
    69
    Posts
    1,133

    Default

    Andy
    as I interpret your cross section, the house is in a hole
    you have to drain the whole hole to somewhere, and slope it away from the building (otherwise your house will end up sitting in a bog hole)
    drains around the top of the hole wont be good enough
    so run the gutter drainage out the same discharge points you use for the surface drainage (maybe on the same line as your proposed dish drain but underneath it — any other services should be much deeper than the 100mm or so cover you will need to the storm water pipe)



    ian

Similar Threads

  1. pergola roof over tile house roof
    By Lbudgie in forum PERGOAS, GAZEBOS, STROMBELLAS & ROTUNDAS
    Replies: 3
    Last Post: 24th March 2006, 05:58 PM
  2. Drainage
    By normc in forum PLUMBING, ELECTRICAL, HEATING, COOLING, etc
    Replies: 19
    Last Post: 28th November 2005, 04:07 PM
  3. Drainage Help
    By jasonbrisbane in forum PLUMBING, ELECTRICAL, HEATING, COOLING, etc
    Replies: 10
    Last Post: 14th August 2005, 10:48 PM

Tags for this Thread

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •