Polymeric sand not holding down

About 10 months ago had a professional crew do my backyard - they placed blue stone pieces and polymeric sand - overall I'd say they did really nice job....
However, recently I noticed, especially after a heavy rain that the polymeric sand is eroding - it gets washed away and seems to be crumbling or forming even some gaps.

As of now it's only few spots here and there.....

Not sure what to expect from it..... shouldn't the polymeric sand be more like cement and really lock in and form solid barrier that can't be washed away...even under heavy downpours ??

Anything I should / could do to "harden" it ? Reinforce in some way ?

Thanks !

 

How big are the joints you're asking the sand to hold?

 

Polymetric sand is intended for small gaps between pavers (around 1/4")!

But I recently installed a new slab for my spa and we had a 3" gap due to the forms between the slab and paver patio.

It was late last year and I had some remaining product so I put it in and am still surprised it's solid even now.

It may just be the product that was installed!

 

Polymeric sand is not great in large gaps like I assume you have with a blue stone patio. Second, it sounds like it may not have been installed correctly. If the polymeric is worked/broomed around too much the adhesive binder separates from the sand. This causes poor adhesion like you describe.

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I have pavers in the walkways of my garden. In some areas I have some odd areas that I filled in with polymeric. Those areas are much larger than the manufacturer recommends. It remained solid and looked good for several years. After 3 or 4 years it did start to break down and erode away but still is mostly solid but it is wearing down at a faster rate than where I used the polymeric properly.

 

adding few pictures just to show the details.... this is almost a year after the job was completed - you can see the sand / particles washing out...

 

I've got polymeric that's been down for over 6 years and it's nowhere near as bad as yours. Judging by the inconsistent appearance I would say they over worked the polymeric when installing it.

 

Over worked, old, cheap, whatever it's an easy fix.

Just need to get a screw driver and scratch it up (we just did a 20x20 paver patio a few weeks ago, took 3 of us an hour) vac up the sand and put down some high quality sand!

 

A high powered pressure washer can also be used to blast out the polymeric. Then when installing make sure you follow the directions.