sidewalks, going under

Discussion in 'Irrigation' started by The Grass Guy, Sep 27, 2007.

  1. The Grass Guy

    The Grass Guy LawnSite Member
    Posts: 69

    I figure you guys go under sidewalks on a regular basis, I want to run the drain pipe off of a down spout under my sidewalk. (currently dumps into a flower bed ) So it will drain into the yard, the yard slopes downward towards the road so the flower bed is higher than where I want it to drain. It currently washes all the mulch out onto the side walk. ( the prev. owner was an engineer ).
     
  2. turfnh2oman

    turfnh2oman LawnSite Member
    Posts: 127

    Suggestion without seeing the ACTUAL thing but, run the line under the sidewalk as you said. Have done this on many lines and works great. Depending how deep it is coming out other side of sidewalk will determine this but if you can't run it to the street curb because of long distance or will be too deep coming out from under sidewalk try this. Come out from under sidewalk and go a few more feet and dig a french drain. Use an auger 6" - 12" and go as deep as possible. Drop a 90 / elbow and short piece of pipe into your hole and fill it with 1" clean gravel [no fines / dust] 6" from top. Put a piece of geotextile cloth over it [staple to side of hole] and topsoil and sod / seed.
    Depth of hole and bigger diameter is the key of success here.
    If it's multiple downspouts running into this line or just a heluva lot of water use a bigger auger like what goes on a Dingo [2 ft. diameter or so] and do the same procedure.
    Breaking the soil hardpan is your goal with depth but if you can't a bigger hole will catch more, keep it off the surface and will eventually sub-surface drain.
     
  3. jeffinsgf

    jeffinsgf LawnSite Senior Member
    Posts: 641

    I did exactly what you're contemplating a couple years ago. I think your approach depends a great deal on your soil conditions and the fill under the sidewalk.

    In the irrigation section of your local big box you'll find a water jet that you glue to a piece of pvc and water blast your way through. This works best if you are putting in the pipe itself -- you just push it through and leave it. It can be used to make larger holes, but it is imprecise, and as you can imagine - MESSY.

    I rented a one man post hole digger. Dug an oversized hole on the outside of the sidewalk and a target hole on the inside. Then I got down in the hole, pointed the auger sideways and shot across. I would not recommend this. Everytime I hit a rock, I couldn't decide whether I was going to break the machine or go to the emergency room. I got all 4 of my drains in, got the machine returned without destoying it and did not actually break any ribs, arms or legs. But it was dicey.

    If you have gravel fill under your walk, and soil that is relatively easy digging, I would just do it manually. Same approach, though. Oversized hole on the outside, target hole on the inside, then attack it with a bar and a trenching shovel. Make sure you have some nice fine pea sized gravel to pack into the hole once you've put the drain hose in. You don't want your sidewalk to settle and crack.

    I ran 4 inch flex non-perf from the downspout, under the sidewalk and about 5 feet beyond. Then I joined it to 4 inch perf and ran that about 20 feet, with a gravel bed and socking on the pipe. Lowe's has a nifty pop-up fitting that I put at the end of each run. When we get a toad strangler, some of them run a fairly steady stream, but it is dispersed and mild, so it never washes.

    Good luck.
     
  4. Jeff those popups eventually cause backup and make for great misquito homes. Not a fan of them. I think it is always best if possible to empty the pipe completely.
     
  5. jeffinsgf

    jeffinsgf LawnSite Senior Member
    Posts: 641


    Hadn't thought about mosquito homes, but to run them to daylight would be a heck of a lot of pipe. And at this point, it would involve tearing up turf I have slaved over for 2 years. The ground would have to be super-saturated for any water to actually sit in the pipe -- since it is perf and laying on about a foot of coarse gravel. Thanks for the heads up, though. I'll watch them and make sure the lids are closing right -- and I'll replace the one I cracked. ;)
     
  6. PurpHaze

    PurpHaze LawnSite Fanatic
    Posts: 5,496

    How wide is the sidewalk and what diameter of drain pipe do you plan on running from the downspout to the "bubble up" in your lawn?
     
  7. The Grass Guy

    The Grass Guy LawnSite Member
    Posts: 69

    Residentual sidewalk around 2 ft wide, I have not measured the pipe but its around 4 inches, my guess is the concrete is around 4 inches thick also. I was thinking of cutting the concrete and just replacing it (my own sidewalk) I have heard everything from a pressure washer to rebar to get the hole going. Any ideas would be great.
     
  8. Mike Leary

    Mike Leary LawnSite Fanatic
    Posts: 22,076

    Getting anything above 1" under any hardscape is a chore....if the "patch"
    does not bother you, rent or hire the concrete cutters. Even at 2' the chance
    of cracking is there..with the cutting, you can water-backfill & the new conc
    will not crack.
     
  9. PurpHaze

    PurpHaze LawnSite Fanatic
    Posts: 5,496

    Heck... At only 2' wide you may just be able to dig under it from both sides with a shovel. We've done this before and been able to sufficiently compact the backfill and cracking never occurred.
     
  10. Mjtrole

    Mjtrole LawnSite Member
    Posts: 226

    Boring rods, over the many years we have aquired every size up to 4" back reamers and have found that sometimes boring under curbing instead of digging under them is easier when installing sleeving.
     

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