My back patio is made from closely placed paver bricks. Weeds and moss grow up from between the cracks. I've pressure washed the whole area off, removed all of the moss, and pulled out all of the weeds.

Should I replace the original paver sand that was between the bricks or try to use polymeric sand? I'm worried that, with closely placed bricks, I won't be able to get the polymeric sand down into the cracks.

It rains a lot here, BTW.


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  • 1
    Honestly, from the photo that looks like a pretty well done paver job.
    – Matthew
    Aug 24, 2020 at 13:55
  • Thanks. Do you think I should do anything extra to stop moss & weeds from coming up from between them. I pressure washed them all out. I scooped up about 2 gallons of wet moss muck and weeds. I could sprinkle in some Moss-B-Gone, but I was worried about it's corrosive label. Round up or similar would work, but again, I was worried about tracking it around. Aug 24, 2020 at 17:38
  • Do you know how old the patio is? And do you know how it was constructed? E.g. how many base layers, and of what type(s), were put down before the pavers were laid?
    – TylerH
    Aug 24, 2020 at 18:23
  • It is less than 8 years old and was done professionally. Unfortunately, I don't know what layers are underneath. It still looks good, though, and lets water drain effectively. The weeds and moss coming up made it look a little ugly and smell mossy. If you look closely, you can see how the bench has settled back a bit. This has pushed it's concrete slab base up a bit in front. The pavers on the left of the bench are pushed up as the slab rocks back. I'm not sure what can be done about this. It isn't that bad right now. Aug 25, 2020 at 0:00

1 Answer 1


I agree with Matthew; this looks like a pretty good paver job. Pressure washing probably did a good enough job, depending on how long it has gone from either being built or from the last time it was cleaned, til the next time it needs cleaning.

However, if you've got weeds coming up (the moss, by contrast, is probably growing downward from transplanted seeds rather than growing up from underneath the pavers), it could be that there wasn't a proper base layer or weed barrier put down. Or, this could just be an old patio; no weed barrier lasts forever,

I would recommend polymeric sand over normal leveling sand simply because polymeric sand is designed to go between the cracks of the pavers and then harden, which has two benefits:

  • makes the pavers move less under your feet

  • makes it more difficult for weeds to grow

When applying the polymeric sand, it is important to use a tamper or vibrating compactor so that the polymeric sand settles down fully into the cracks; you don't want air pockets in it when it is setting. After that, be sure to wet the sand per any provided instructions and let it set before walking around on it.

Also note that polymeric sand is recommended to be reapplied in a touch-up capacity every year or so.

  • OK. So if I do put down polymeric sand, I'll have to rent a tamper. With the pavers so close together, I don't see how I can get it to settle down and be effective. The Sackrete PS I almost bought said that it was only for 1/4" and above. The grain wasn't fine enough, I'd guess. These pavers are basically adjacent to each other. Aug 25, 2020 at 0:03
  • @DanielWoodward Yes, that's a valid point -- polymeric sand is usually for joints of a certain width. If they are adjacent to each other, e.g. not even 1/8" of space, then it's probably not worth putting polymeric sand down because the grain sizes will be so large that significant quantities won't be able to fill the gaps. For flush installs of pavers one usually wants to put down a couple inches of paver base (crushed gravel) and another inch of leveling sand before putting down the pavers to deal with weeds, since polymeric sand can't really fit in those joints.
    – TylerH
    Aug 25, 2020 at 0:52

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