Dual Slope/Laser Level

Discussion in 'Hardscaping' started by bt99yz125, Nov 13, 2007.

  1. bt99yz125

    bt99yz125 LawnSite Member
    Messages: 29

    I was just wondering if any body had any good techniques or reference books on setting up the slope for patios/walkways? I have searched on the lasers website site but have not found any good info to keep with the laser at all times. I have single slope down but dual slope seems to be confusing me mainly bc of were i should have the laser positioned or if it matters? I would love to here your setup styles/preferences. Correct me if I'm wrong I have not seen to much info on the forum about the subject beside if to buy a dual slope laser was worth the money. Also i have about a $1200 spectra laser that self levels and has the dual slope function. I figured the manual that came with the laser would shed some light but basically it only tells u how to turn it on!
  2. AWJ Services

    AWJ Services LawnSite Platinum Member
    from Ga
    Messages: 4,281

    Ignoring the grade in percentage terms just draw out the patio and reference the 4 corners.

    Say 2 corners are next too the house and they will be level.
    You take the 3rd corner and determine the fall too it.
    Say you want 4 inches of fall too that corner just raise yor reciever on the stick 4 inches from the level of the first 2 corners and set your first grade too it.
    Then move too the fourth corner wer you will want 6 inches and repeat above process.

    The grade is done in percentages which is confusing.
    A 10 percent grade will be 1 over 10 foot.
    A 5 percent grade will be 1/2 foot over 10 foot.

    Most people use terms like 1/4 inch per foot.
    This is very hard too convert too percentages of grade.
  3. ChampionLS

    ChampionLS LawnSite Bronze Member
    Messages: 1,066

    You should place your laser where it's not in the work zone. You will need to manually determine your slope first. Example: Your doing a driveway and the street is 6" lower than the garage. You will first determine this by using the laser set to level. Next step is to angle the beam on the X or Y axis. A single slope laser will only adjust in one axis, while a dual slope laser will adjust in both. It is important to set up the laser so it projects in the right direction- in this case, up and down the driveway. Set up the laser for grade and press up/dn or +/- (you may need to press and hold, or press to fine adjust) and take a reading at the garage and street. Check the differences. You will need to keep adjusting the laser until the readings are 6" apart.

    NOTE: As the beam goes up on one end, it goes down on the other, so you must take two readings each time.

    When it reads 6", set your receiver to the desired height at the lowest point (street) which is where you should be starting and work your way up to the garage. Anywhere you take a reading from now on will have the perfect 6" slope along the entire driveway.

    The only drawback is, make sure you have fresh batteries, or if possible a AC adapter. If you move the laser or shut down for the day, you will lose your settings. (at least with mine) Newer ones may be different.
  4. bt99yz125

    bt99yz125 LawnSite Member
    Messages: 29

    sounds good keep it coming
  5. Captains Landscape

    Captains Landscape LawnSite Senior Member
    Messages: 333

    Good thread. I have yet to purchase a laser. I've never used one before and it doesn't sound like something you take out of the box and your good to go. I hate working around string lines & line stretchers. What would you suggest for someone who has never used one before? Do the manufactures put on demos anywhere, or is it easier than I think. I always counted on a friend of mine to use his transit if I ever contracted a driveway, but now it time to purchase one.
  6. bt99yz125

    bt99yz125 LawnSite Member
    Messages: 29

    Put it on ur xmas list bc they r the best thing ever! It does take a little math when you use the slope functions. But for level retaining walls it has been the best 1200 i spent yet! I do wish i paid a little more attention in math class though. I highly recommend the self leveling and dual slope for hardscaping.
  7. pls8xx

    pls8xx LawnSite Member
    Messages: 64

    All sloped plane surfaces can be defined as a single slope. Some plans define a plane with a running slope and a cross slope, or two items of data that could be converted to a single slope. Thus a dual slope level can be handy for these projects, but with a little math a single slope level can be used just as well.

    I did a sample of this in the following thread ...

  8. ChampionLS

    ChampionLS LawnSite Bronze Member
    Messages: 1,066

    I'll try to make this sound easy as possible. First came the string line. String lines are great for establishing a straight line between two points.. A string line is best used in hardscaping for keeping your bond lines and lines of reference optically straight. :waving:

    Next came the clip on bubble level. You know...that little two pack..one red one black, which seems like the easy way to convert your string line to a perfectly level plane (or one with a slope). The biggest problem is GRAVITY! I'll say it over and over and over. You CAN NOT pull a string line tight enough..even if you had two army tanks playing tug-of-war with it. Once you hang that 1/4oz plastic toy on it, the line will sag. This only worsens when suddenly your string line gets wet and it loosens (that mid afternoon rain storm, or the sprinkler going on) Then there's the common "oops" I tripped over it or bumped it with the wheelbarrow. So much for that. :cry:

    So lets say you DO take the time to get that string line nice and tight. Hang that thinggy on there and now what? Which end do you level? ok ok start on one end...loosen the string..tighten the string...do it again over and over. OK it's perfect now- We got the string line at the exact height of our finished patio. We know this because we put the string lines right over our work area, so as we excavate, and bring in base material, we gotta watch out for that string line. I've seen jobs with so many string lines you'd think there was a mine field under there!. UGH!. :hammerhead:

    Next, you have your Transit. This is supposed to make the job go quick and easy. First you gotta set up the tripod. Get that somewhat level, and then mount the scope and level it too. There are two screws. One to level your "X" axis and one to level your "Y" axis. Just fyi- this is a two person deal.. one person to hold the ruler, and somebody with a good eye to focus in and see where the cross hairs read. This is about as quick as photographing a wedding with a camera that doesn't have auto focus. :laugh:

    So one day the Laser was invented. A laser emits a intense beam of light over a very long distance, without bending. Most simple lasers are accurate to +/- 1/8" over 1000 feet. I can't think of anything that needs to be that flat. Anyway, you still set one of these up on a tripod and level the unit in the "X" and "Y" Axis. Cheaper lasers are fixed- they don't rotate. This works fine for indoor work or working in a small area. If your one of us and you do Hardscaping, you need a rotary laser to cover a larger area. When your using a rotary laser, the intensity of the beam is spread out over the entire work area, so you'll need a laser detector on your ruler. Cheap detectors have a small receiver optic while better ones have a longer receiver optic, and usually a digital read out display on both sides. The taller receiver allows for you to visually see how off your grade is and make adjustments. The double digital display is helpful because the operator can stand in front or behind the ruler to take a reading. Hint: IF your standing in between the laser and the receiver, the laser is on your back, so your better off taking your readings from behind. :dizzy:

    Now came a time when the self leveling laser was invented. This is better than sliced bread. There is no guesswork involved. Open up your tripod (Or not... you can place the laser on anything.. a BBQ, a pallet, wall, car etc.) Turn it on and in about 10 seconds, it will self adjust and start emitting the beam. There is no guesswork involved here. Nothing to go wrong. It's a one man operation. You can take readings anywhere, and mark your grade. (usually with a DEE stake and ribbon) I like to map out a grid in 5' x 5' increments. Once all the stakes are in, I set the grade by tying a ribbon to the stake and level it using my ruler.

    Now comes the fun stuff. You can excavate, or bring in base material and there are NO STRINGS to trip over. We simply start the furthest away from the load of material, and level it with base rakes. It's all eyeball work from here in. We use the ribbons as a guide to get it right. It's like over sized graph paper. If your crew has trouble leveling the base between the stakes, they need to hit the road. :dancing:

    If you want to go one step further.. get a grading laser. You can adjust the "X" or "Y" axis (depending on features). This is great for sloping driveways, setting pitch on a large patio or lawn area. The only tricky part about any laser is to understand how the beam is projected. You don't need a super expensive laser either. Usually you can get a kit, which is a Aluminum tripod, Self-Leveling rotary laser in a hard carry case, Double sided laser receiver, and an Aluminum telescoping ruler. Average about $1,000. :clapping:

    SOUTHERNGREENSCAPES LawnSite Senior Member
    Messages: 763

    good information here. Isn't it great how technology helps us out so much. I understand how the grading laser works, but couldn't you use the same technique with a long driveway as you are talking about using on a patio, but just use longer distances between stakes. Say 10 feet. or just do the math on the stick. I guess i am just not sold on the dual slope laser yet. I still use the single slope kit that i got from Home Depot for about $350 that came with the laser, glasses, receiver, stick and wall mount all in a nice little case. The only thing i do wish mine had was the self leveling.
  10. Captains Landscape

    Captains Landscape LawnSite Senior Member
    Messages: 333

    ok Champ, that being said, what kind of laser do you have? Where did you get it? Are you happy with it?

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