polymeric sand or pre emergent easily washes out of sloped driveway?

Discussion in 'Hardscaping' started by roody2333, Jun 19, 2018.

  1. roody2333

    roody2333 LawnSite Bronze Member
    Messages: 1,019

    650 sq ft paver driveway (regular size) with tight joints (pavers are tight to each other with only 1/32 or maybe 1/16" joints). Polymeric usually needs a minimum of 1/16" joints, some products need or suggest 1/8".

    Has some weeds but not too bad. I've sprayed it before and of course weeds come back a few months later.

    Am thinking prodiamine pre em would wash out if I try to do a cheap fix by spraying pre em after round up kills weeds and weedwacking what I can. I don't want to stain these pavers with pre em either. Unless it's a minor and equal discoloration that doesn't make it look bad or noticeable.

    It's not very sloped, maybe 2 feet over 25 foot but with a couple pouring rains I think pre emergent will just wash out. I know regular sand will also wash out. I'm guessing polymeric sand will wash out in one or two seasons but I'm not sure.

    I am/was considering Technisoil NanoPave JSS Ghost 2-in-1 Joint Stabilizer and Sealer

    it's meant for regular sand joints up to 1" wide, and if joints are 1" - 4" wide it should be a mix of crushed stone and sand -- it basically glues it all together and is okay to spray on paver surface (it's a sealer too) and lasts a few years then needs to be re sprayed the company has told me previously.

    Even if I just spray these weeds dead, powerwash the joints and put no sand (because the joints are so tight) this product might just fill the joints with glue and keep it weed free for a few years.

    the only goal is to prevent weeds, doesn't matter if joints have visible sand.

    Cost would be about $200 for 7 gallons for 650 sq ft driveway.
    would polymeric cost be about the same?

    What other options are there that will last a few years or more? Preferably cheap if possible. thanks
  2. Delmarva Keith

    Delmarva Keith LawnSite Senior Member
    Messages: 534

    For pre-m, I use dithiapyr on the hardscapes (same as the lawn, it’s in the tank, cheap enough and it works). Have not had issues with washout of effectiveness on tight pavers or loose. No stains. Only downside — it smells bad when you mix and spray it, like model airplane glue :).

    I’ve used the polymeric sand in a tightly jointed brick patio and wasn’t impressed.

    For wide joints, regular stone dust is my go-to. Compact it properly and it will last a decade or more.
    That Guy Gary likes this.
  3. That Guy Gary

    That Guy Gary LawnSite Silver Member
    Messages: 2,412

    I sprayed a lot of dithiopyr mixed with prodiamine this year for churches, treating beds and cracks in sidewalks and parking lots on the older sites.

    The prodiamine was visible on the concrete when applied but quickly wore off and didn't leave any permanent or even long term stains.

    It's been effective and these cracks see a lot of running water when it rains. If I could only choose one I'd prefer dithiopyr, it's got a much larger spectrum of controlled weeds.
    Delmarva Keith likes this.
  4. JimLewis

    JimLewis LawnSite Fanatic
    Messages: 6,890

    My reco would be to re-install polymeric sand using Techniseal NextGel. That's the hardest setting poly sand we've ever used and seems to outlast all of the others we have tried.

    It also depends a lot on the paver. If it's a paver that has a tumbled edge to it, there are going to be natural dips and voids in between the pavers, where it's just not feasible to fill those joints all the way. In that case, if the patio/driveway isn't kept clean eventually dirt and dust will settle in those joints and then eventually weeds will work their way in. The solution, IMO, isn't to install a pre-emergent. I think the solution is to keep the patio/driveway clean and then if needed, use a post-emergent like Roundup. And of course, a poly sand that will last.
    hort101 likes this.

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