[LongIslander]

I had my front walkway and driveway redone with Cambridge paviing stones. The contractor laid a concrete foundation for the pavers. They used fine sand for the joints and did not do any compacting. They said it was not necessary. Needles to say, the sand has been blowing away and getting washed away when it rains. I want to wash out the sand completely and replace it with Polymeric sand. The manufacturers of the Polymeric sand all seem to recommend using a compactor to make sure the sand fills in the joints before wetting it down. I was thinking of renting a gas powered plate compactor. However, I am concerned that because the pavers were installed over concrete rather than sand, that they may crack or get damaged if I use a plate compactor. Please let me know your comments. Thanks.

[AZTLANLC]

did they use any bedding material between concrete and pavers if not I'd suggest against compacting pavers.
And for some reason manufactures don't recommend to put polymeric sand when pavers were laid on top of concrete.
Unilock and other manufactures have a product that is called sand stabilizer you can use that on existing sand just apply some more where wash out has occurred at the same time it will seal the pavers too.

[Stonehenge]

If those pavers were laid right over concrete, then your contractor was correct to tell you they don't compact them. Unless the broken paver look is what you're after. Not to mention the challenge of just holding onto that compactor when run over a solid surface!

Silica or other sand will wash out in time, and polymeric sand has been our default for paver projects for the last 4 years or so. So I'd be in favor of that. But don't compact those pavers! If you really feel the need, go buy yourself a $15 hand tamper at the local hardware store and lightly tap those pavers to get the sand to settle. Or rent a hand roller and only fill it up partway - enough to jiggle the pavers as it rolls, settling the sand. Re-sweep, re-tamp, sweep one more time, then wet it down.

[Rex Mann]

Check with the manufacture of the polymeric sand you want to use, but
most DO NOT RECOMMEND their product be used in an overlay installation.

Peace,

Rex

PAVEREXPERTS.COM

[LongIslander]

Thanks for the quick responses! I did see them put a layer of some loose material (it looked like dry cement/sand mixture) over the slab so I assume that was the bedding material. I will contact the polymeric sand manufacturers and see what they say (they all have web sites with contact info these days). I will also take a look at the sand stabilizer products. Thanks again.

[AZTLANLC]

Rex I have read that before but maybe you know the answer about not using polymeric on overlay what is the reason?