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Disclaimer: I have no clue what I'm doing

Over the weekend, I replaced our mulch bed with some rock and a small paver path to our yard: enter image description here

I laid a thin layer of paver sand under the path, and scrubbed in some sand between the pavers. I sprayed a mist of water a few times over an hour or two to get the sand wet so it would settle. The paver sand doesn't seem to be strong enough though? When I walk on the path, the pavers still shift slightly (enough to make the sand dislodge from the cracks) and I have to refill with more sand, wet, let dry, test again.

Can I use something more rigid? Is there a trick to getting these to stay firmly in place?

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    +1 for the disclaimer! – Criggie May 2 '18 at 0:56
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Sounds like you need a firmer subbase under your sand to spread the load across a wider area.

I would follow the same procedure as for laying a wider area such as a patio. It seems like a lot of effort for a small area like the one you have but unless the ground underneath is already very hard and level, the pavers are going to settle unevenly and/or slide horizontally.

  1. Lay a subbase made from a mix of aggregate sizes several inches thick. This type of aggregate locks together nicely and spreads the load across a wider area so no single paver sinks more than the others.
  2. Compact using a plate compacter (tamping down with a large piece of timber or a cinder block would be ok for small areas).
  3. Excavate around the edges and bed the edge pavers in concrete. This prevents the edges of the subbase and sand from crumbling away. Make sure to "haunch" correctly, as shown in this great resource for paving projects.
  4. Lay an inch or so of sharp sand on top and level it off.
  5. Finally, lay the rest of the pavers.
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A couple things to add to the other answers and some other options:

You mention wetting the sand to make it settle. Think of building a sandcastle. If you put water in bucket full of fine sand, it's won't come out easily. It clumps. If you want to make it flow when wet you really need to basically have a pool or flowing water.

Fine sand, when wet or damp clings together. This brings us to the question of what is under the sand. If you put the sand on top of gravel and then wet it and put the pavers on top, this is exactly what happened to me when I built a patio once, just over a longer period. the wet sand clumps and will hold together on top of the gravel, even with a vibrating compactor. Then when the sand gets really dry, it will start to fall leaving voids.

Another option is stone dust. It packs together more tightly than sand. Otherwise, if you are putting the sand on top of gravel, it will continue to fall through until pretty much every void between the rocks has been filed in. If you don't have a border, it will move out of the sides and you will need to keep filling it in. Don't bother with polymeric sand until you get the settling issue solved..

  • "a mist of water" - Nope. Use a garden hose,+1. Legit jobs use a vibrating compactor +2, and stone dust ('fines') over large gravel that's there for drainage, under the topcoat of fine sand. All of which is above undisturbed soil <muy importante. – Mazura May 1 '18 at 23:42
  • When I helped friend’s successfully lay stones in sand, we practically floated the stones. Agreed that misting is probably not doing much, if anything. – Todd Wilcox May 2 '18 at 5:04
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Pavers take time and use to settle. The sand you applied probably has voids under it which are still collapsing, and you'll need to reapply it a few times. I tend to put a layer of sand over the pavers and let it fill on its own as I walk. You could also tap the pavers with a wooden post to speed the process.

Unless they're really shifting around, be patient. If you still have substantial movement after a few days of regular use, reconsider the base you built on. Soft organic soil below the "thin layer" will be a problem.

  • Somewhere I saw that leaving the sand on the pavers could lead to staining -- is that the case? – ctote May 1 '18 at 17:08
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    Clean sand doesn't contain anything that really could stain. – isherwood May 1 '18 at 18:15
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    The polymeric sand will stain the pavers if it is activated (gets wet). – jamesbtate May 1 '18 at 18:44
  • That's not sand so much as grout. "Polymeric" implies fortification with (presumably dyed) synthetic binders. – isherwood May 1 '18 at 18:55

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