determining pitch

Discussion in 'Hardscaping' started by tractrpowr45, Feb 13, 2006.

  1. tractrpowr45

    tractrpowr45 LawnSite Member
    from NY
    Messages: 32

    Hi, I am starting a landscaping business in the spring, and I was wondering how you set the right pitch for a paver patio. I know that you are supposed to have a 2% pitch, but I was wondering how you accomplish that? Do you just screed the sand slightly out of level before laying the pavers? I know a slight pitch is needed to shed rain away from the patio, but I'm just not sure how to do it. Any help is very much appreciated. Thanks headphones
  2. LandscapePro

    LandscapePro LawnSite Member
    Messages: 138


    Set your pitch with your base. Then screed an inch or so of sand evenly on which to set the pavers.

    1 inch fence rail works real nice. It doesn't take a whole lot of pitch to shed water. I usually go with an inch to an inch and a half for every 8 feet of run.

    Hope this helps...

    La. Landscape Contractor #2576

    UNISCAPER LawnSite Bronze Member
    Messages: 1,426

    I'll assume you know what 1,2,3% gradiations are and go to the methods.

    We usually set the grade in the gravel and soil excavation application. Since you are just starting out, you probably don't have a laser or site level, so, you will have to use string lines. You drive stakes every 8' in square box configurations and draw strings level across the gravel. Measure from the string to the top of the gravel, the end farthest from the house will have more distance between the string and the gravel.

    After you set the gravel base and compact it to the grade you want, just drop your 1" pipes on top of the gravel and screed an inch of sand over the base. Then lay the pavers.

    If you are yuppifying your operation with a lazer or site level, you won't need the strings, you can just shoot a 8' diameter grid pattern across the patio and your good to go.

    In weird applications we have had to keep both ends at the same grade and drop the center of the patio and set drains within. We tend to go 1% on those applications.
  4. PurpHaze

    PurpHaze LawnSite Fanatic
    Messages: 5,496

    Bill... Is this so you won't end up with a noticeable dip area in the patio, whether to the eye or the feet and balance of someone walking in the area?

    UNISCAPER LawnSite Bronze Member
    Messages: 1,426


    In Ca., it is illegal to dump water from your yard on someone elses yard, where in other states, it's acceptable to place it on the lot lines from both yards. So, when you have a 15' deep back yard that the client wants paved, the only way to keep the water inside the lot lines is go with a 1% pitch from both ends toward the middle and bring some 4" square brass topped drains to the elevation the brick sits at. Looks has nothing do do with it, it's something they need to deal with because of the codes. In all reality, it is only an inch low on center, so, it's noit as bad as it sounds.
  6. cgland

    cgland LawnSite Bronze Member
    Messages: 1,929

    Bill - Where do you take the water in this application? Into the rain leader system?


    UNISCAPER LawnSite Bronze Member
    Messages: 1,426


    99% of all yards built within the last 10 years have an underground system of drains. Typically, they install a 4" SDR-35 rigid pipe and place atrium topped drain grates in low spots the yard had been graded to. So, when we come in, we gauge where the pipe is, and many times we end up taking an ultrasound to find how deep the pipe is, set the lazer to the depth we need without destroying the pipe, and add as much or as little as we need. Most of the time, gutter downspouts are never added to the system, let alone if the builder included gutters on the house. So, the drains we place in a patio would typically connect to the main builder installed system.

    Then there are those which don't have drains. That makes for a nice $6-7,000 add on to the job, and many times I would just as soon do the drains myself. Open the trenches, set the pipe, back fill and wack the trench.
  8. neversatisfiedj

    neversatisfiedj LawnSite Bronze Member
    Messages: 1,028

    Have anyone ever installed a drain in the middle of the walk and drained into a gravel pit ? If you could not outlet water to lower elevation ?
  9. PurpHaze

    PurpHaze LawnSite Fanatic
    Messages: 5,496

    Thanks Bill.
  10. PurpHaze

    PurpHaze LawnSite Fanatic
    Messages: 5,496

    These are called "dry wells" in our area. We had one school built about 12 years ago that used these dry wells as a means of sending large HVAC unit's condensation lines to. They located the dry wells in turf areas only about five feet from drain inlets to the storm drain system. Before the school opened I was doing an irrigation system walk-through and asked someone what would happen when the irrigation water filled the dry wells. Answer: "Architects know what they're doing." This worked fine in the spring when the irrigation program times were minimal but the dry wells started filling up when we changed to hot weather programs. In turn the condensation lines stopped working. Within two years they had to go in and reroute the condensation lines into the storm drains. :dizzy:

    An afterthought. They do use dry wells successfully for smaller HVAC units on portable buildings.

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