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Fixing someone else's screwy flagstone job . . . Gator Dust and Flagstone

Discussion in 'Hardscaping' started by Century Landscape, Aug 17, 2011.

  1. Century Landscape

    Century Landscape LawnSite Member
    Messages: 87

    Hey guys,

    A few questions about a flagstone job I went out and looked at this morning. This potential customer had another guy who installed about 1500 sq ft of flagstone for him and man! is it screwy. The stone is completely unlevel, has 3 or 4 really large sunken areas, and the polymeric sand he used to fill the 1"-3" joints is washing out in a lot of places. In addition to the huge drainage problems, this guy has several gutters draining directly onto the patio.

    Okay, so I'm pretty sure I know all the things that need to be fixed and how to fix them, but just wanted to double check a few things and get some opinions.

    1. Do you typically install underground drainage for flagstone? This guy installed perforated pipe underneath his gravel base ( not even sure what kind of base he has right now, I have to check ) that all ties in to a sump pump. Some of his drainage pipe is not coming from any surface drains - it's kind of a French drain style where it would all seep in. This perforated pipe is buried in the base beneath the flagstone and polymeric sand, which the installer was going to seal again. If you install polymeric and seal it, would any of the water drain off the patio, through the sand, and into the perforated pipe anyway? It seems like it would just runoff - isn't that one of the points of polymeric and sealer, to keep water from seeping in? Which brings up my next question

    2. Does Gator Dust drain? Gator Dust is what I told the customer he would need to go back with due to his large joints, but I don't think the Gator Dust is permeable necessarily - is it? I planned on just re installing the flagstone with enough slope to facilitate runoff to the sump pump drain.

    3. Can you seal Gator Dust anyway? Won't Gator Dust be already sealed due to the polymeric in it?

    4. Shouldn't the gutters be drained underground to sump pump? I would think that it would certainly be best to close in the gutter system instead of having it spill all over the patio and then have to worry about draining it to another location or providing a piped open drain. Wouldn't you agree?

    5. For underground drainage, do you find that rigid perforated PVC works better than the corrugated stuff? I've never used either, but seems like in the long run, the PVC would hold up and drain better. A few thoughts and some experience on that if anyone could offer would help.

    In summary, I'm thinking I'll probably have to remove all the stone, or at least most of it, along with the sand. Then verify the base this guy used, grade and level it, then correct all the above listed drainage pipe and gutter drainage issues, and reinstall all the flagstone with Gator Dust instead of polymeric sand. Anything I missed? or any pointers?

    Thanks for all the input. You've just got to love cleaning up after other people:hammerhead:
  2. DVS Hardscaper

    DVS Hardscaper LawnSite Fanatic
    Messages: 6,576

    hmmmm......ok, let me get this straight. So you need to know how to build a patio so you can fix someone else's flawed patio????

  3. Century Landscape

    Century Landscape LawnSite Member
    Messages: 87


    No. What I was wondering about was if you typically install underground drainage other than having the proper base underneath. If I had installed this for this customer, I would have used 3/4" minus limestone or road base as a base, then some stone dust underneath the flagstone. I always understood that the 3/4 minus would provide the drainage underneath whatever type of patio you install. The person who did this install used some type of stone compacted with a hand tamper, and buried perforated pipe underneath. To me it seems unnecessary. If you have low spots or need the patio to slope to a drain, drain it there with a surface drain, piped underground to a sump pump. I just don't see the need for the perforated pipe generally spread out under the patio. Do you normally install that type of drainage? that's my question.

    I do appreciate the fast response.

    The drainage wouldn't be nearly so much of an issue anyway if he had installed the patio with the proper slope. This dude didn't grade or dig out any of the places he should have. he just put some perforated pipe in the ground and thought that would get the job done. Big surprise, it's not working out.

    It just seems strange to me, that's why I'm looking for a few other opinions.

  4. Bru75

    Bru75 LawnSite Senior Member
    Messages: 582

    I don't know why the perf pipe would be needed unless there is some sort of ground water issue.
    I would run the downspouts under the patio in schedule 40 pvc to daylight, never over it. I would also suggest that you don't drain the gutters to a sump pump, what happens when the pump is overwhelmed by a downpour or the power goes out?
  5. PatriotLandscape

    PatriotLandscape LawnSite Bronze Member
    from MA
    Messages: 1,209

    Who uses sump pumps outside?

    We usually use drywells.

    Chances are if this guy just paid to have it done he won't want to pay you to do it right the second time.
    Posted via Mobile Device
  6. Century Landscape

    Century Landscape LawnSite Member
    Messages: 87

    That's what I was thinking on the perf pipe. He's had the sump pump for years and loved it. His drainage problems now all stem from his really uneven patio. Big bellies and dips.

    I don't know if he'll want to pay to get it done right once I give him a proposal, but he pretty much can't leave it like it is and he told the other guy to not come back to his house.
  7. scagrider22

    scagrider22 LawnSite Bronze Member
    Messages: 1,272

    Lawnsite should take after facebook and add a 'like' button! :laugh:
  8. GroundOneMN

    GroundOneMN LawnSite Member
    Messages: 81

    Say what?

    I am going to go out on a limb and agree this HO will not pay for the proper installation as it is evident that he went with the cheapest guy who thought perforated tile under a patio was the correct thing to do. I do wanna see pictures though of this maybe it will explain things better.
  9. Century Landscape

    Century Landscape LawnSite Member
    Messages: 87

    I'll post some pics real soon. So far I just did an initial consultation, but have to go back in the next couple days to actually pull some of the flagstone up and see what I'm working with underneath. I'm sure curious to see!
  10. PatriotLandscape

    PatriotLandscape LawnSite Bronze Member
    from MA
    Messages: 1,209

    Why waste your time. Give him a ballpark and we if he is interested. Don't chase a job where the last guy got thrown off. It may be the customers fault not the contractor. Two sides to every story
    Posted via Mobile Device

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