drainage... what would you do

Discussion in 'Hardscaping' started by woodlawnservice, Jan 26, 2018.

  1. woodlawnservice

    woodlawnservice LawnSite Bronze Member
    Messages: 1,180

    new patio off back of the house... grade drops 5" over 25' and then a big concrete retaining wall with a french drain that runs along it and dumps out on the ends.. house was built into side of the hill... they want the new pavers to run all the way up to the wall and maintain a slope away from the house. how would you handle the drainage here. They want a new french drain installed under the edge of thw new patio...ekkk
  2. Junior M

    Junior M LawnSite Fanatic
    Messages: 13,686

    We call them deck drains. Or trench drains. Install them where ever you feel necessary.

    They’ll carry a bunch of water.. I can’t think of the manufacturer right now but they make different colored tops and some with designs.
    hort101 and woodlawnservice like this.
  3. Mr. Jon

    Mr. Jon LawnSite Member
    from Jersey
    Messages: 161

    Yes, trench drain or channel drain. Set it in concrete with the concrete 3" below grade so you can run the pavers up to it. Drill holes in the side of the drain for any water in the setting bed and cover with fabric.
    Not sure by reading your post, is it a cut wall of a fill wall?
  4. TPendagast

    TPendagast LawnSite Fanatic
    Messages: 15,185

    Can’t you install drain grates in the paver patio?
    They make parts/accessories just for this reason.

    I deliberately look for reasons to use them... I dunno it’s like a power window button, it’s there so I have to play with it.
    woodlawnservice and knox gsl like this.
  5. woodlawnservice

    woodlawnservice LawnSite Bronze Member
    Messages: 1,180

    problem solved, opted to keep pavers 24" off the retaining wall and install a french drain in that void, up top will be a decorative rock landscape bed with some plant work.
  6. visionscapes35

    visionscapes35 LawnSite Member
    Messages: 7

    Maybe im confused but a french drain will do nothing for surface water, af french drain is used to capture and direct sub surface water, aka water that comes from the ground out because of a perched water table
  7. woodlawnservice

    woodlawnservice LawnSite Bronze Member
    Messages: 1,180

    combination of a french and trench drain did the job
  8. JimLewis

    JimLewis LawnSite Fanatic
    Messages: 6,890

    The channel drains are always a good idea. But we've also installed a lot of them in this situation where we install a really small French Drain in between the edge of the patio and the wall. Often times what's seen at the top is just a 2-3" section of the French Drain system, but the drain system itself is actually more like 6" wide or so. It's just that the last pavers hang over the edge of the french drain a little, to minimize it. Which, I know, doesn't sound like it would be stable. But we've done it many times and it is very stable, as long as the rest of the paver is on a firm standard paver base then if a little hangs over the drain and if the rock inside the drain is compacted down so that it doesn't move, it will work. I've attached a diagram and a few photos of patios where we've done it this way and I've been back to these patios a year or two later and they're still solid. DrainageBetweenWall&Pavers.jpg DSC_0421.jpg FrenchDrainInPatio1.jpg RafBest14.jpg
    hort101 likes this.
  9. Mr. Jon

    Mr. Jon LawnSite Member
    from Jersey
    Messages: 161

    What do you use for an edge restraint?
  10. JimLewis

    JimLewis LawnSite Fanatic
    Messages: 6,890

    Snap Edge. The spikes that hold Snap Edge in will go right down into that drain system just fine. With the stone pavers that you see in two of those photos, we use the low-profile snap edge. The French Drain has Perforated ADS pipe in it. So if a spike goes through the pipe, it isn't a problem. It's perforated anyway.
    Mr. Jon and hort101 like this.

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