[johnkeegan]

I have an irregular flagstone patio that we did over a year ago. I put polymeric sand in the joints as I've successfully done before but this time there seems to be a problem in that the mix doesn't seem to ever dry. It stays in that "gooey" stage. Perhaps a bad mix? Or maybe the larger joints require a different mix.
Anyone have a similar problem or ideas on solution.
P.S.- The patio pretty much gets full sun.

[Stonehenge]

Which type of polymeric sand did you use? Organic binder or synthetic?

[johnkeegan]

I've been using "Paverlok," an organic polymer.

[Stonehenge]

I haven't heard about that sand staying gel-like when in full sun, so I can't say why it's happening. Maybe it is a bad batch. You might want to try the synthetic binder types of sand - we've had more consistent results with it.

[johnkeegan]

I think I'll try Unilock's premixed blend for larger joints. Perhaps I mixed the polymer and sand wrong. Maybe too heavy on the polymer.

[Greensmith]

I was thinking that as well. To much polymer and it melts to elmers glue consistency during the heating of the sun?

[Keith N]

My father in law is pulling all the polysand out of his flagstone patio we did last October and mortaring the joints. I'd say 30% of the joints stay soft. I used Techniseals HP grade. I've read about Alliance Gator dust for joints up to 4" but I have never used it

[johnkeegan]

I talked to a guy at "SandLok" and he said their testing has shown that in larger joints it's best to fill the joint 1/2 way with the largest aggregate that will fit in the joints and do the other 1/2 with the polymeric sand.

[HRLand]

I was planning on picking up some techniseal hp tomorrow to fill the joints on a patio we built at my house this week. Now what do I do? I don't want to mortar dry laid flagstone.

[Stonehenge]

Go ahead with your plans - we've had success with big joints in flagstone, doing nothing differently than we would for pavers.

[und3rd06]

Hi,

I have read a lot on the subject on this board. As usual the search tool was my friend ;-)

I seem to have the same problem ...my poly sand won't stick !!! it stays in the "goey" stage. Here is more information. Hopefully someone can pinpoint the problem ? Or it might be a bad batch

Here is the info.
Please note that I am starting landscaping purely for the fun of it. I bought a house 3 years ago and the front and back was a mess so I removed everything and rebuilt everything with my own hands. Since I am new the terms or definitions might be off. I'll try my best here goes....

Product: Synthetic Sand Polymer.
Company: Permacon - PermaPro SP - Permapro | Sable polymérique SP

Temperature when installed was 15 Celsius, no sun.

2 years ago I went and put in some square 1 1/2 patio stones next to my pool. I have 3 inches of 0 - 3/4 and on top of that I have 3 inches of dust
I did not put anything in between the patio stones (i.e.: nothing in the cracks)

Now last year I had a lot of weeds in between the cracks so this year I wanted to add polymer sand in the cracks.

I took a steak knife and removed the sand and and organic matter that was in the cracks. The Cracks are 1 1/2 inches deep and are 1/4 inch in width !
After removing all that stuff I put the polymer sand by hand in all the cracks. I did not use a compacter to push in the sand because I am scared it would break my patio stones. So I proceeded to push in the sand by hand using the same knife.

I then gently added some water and then it started to rain so I stopped. It hasn't been sunny for 4-5 days and it has rained every second day since the installation. My polymer sand is still in that gooey stage.

Now here are 2 things I would like to point out.

I didn't sweep the excess poly sand from my patio stones. It didnt' rain the next day and I didn't have any problems removing the excess poly sand I didn't remove the day before...It was far to easy to remove unlike the statements I have read here :
the 'sticky' side to polymeric sand

Now the other important thing to point out is that this is a pre-mixed bag and I think it caught humidity. I found that the grey colored sand was very dark at the top of the bag and it was a lot lighter colored in the bottom of the bag. I also found a 5X2X2 chunk of solid poly in the top of the bag...did I get a bad batch ???

it's supposed to be sunny and in the 24 celsius for the next 3 days will this tell me if my installation was success or should I start all over right now since it's going to be sunny for the next 3 days !?!?!

thanks for your time.

[natural12]

Are you an engineer by trade?

[Stonehenge]

Steak knife, huh? Must be a glutton for punishment.

For premixed bags of poly, there should never be clumps - it should be as dry as table salt. So that might be part of your problem. 15 degrees celsius is 59 fahrenheit, which might be close to the lower temp limit for that sand (check the bag).

[und3rd06]

Thanks that answers my question it's a bad batch. and 55 Farenheit was the minimum temperatrure to install so I am ok there. And yes it was a long task but sice the cracks were so narrow I couldn't find anything else to remove the earth and vegetation that was between my stones. I should have put poly right after I finished laying down the stones 2 years ago...lesson learned the hard way ;-)

Thanks for the reply. IT's supposed to be hot for the next 3 days so if the poly finally "settles" I will put a reply to this thread.

[johnkeegan]

I see that this thread was opened again. I removed all the original polymeric sand from those joints and then used a premixed version. It's the same one we've used on all stone and paver patios the last few years with no problems. But that patio which sparked this thread still seems to have a problem even with the new sand.

I think I know the problem, however. That house was built into a side hill that seems to have been home to alot of underground springs. We did all the normal base preparation and had even installed some "French drains" to redivert surface water. And when we did the inital prep work for the patio it had been dry for awhile, so I did not notice or suspect any unusual wetness.

But, I believe alot of that ground water from down below migrates upward after heavy rains and it stays damp under the patio (the surrounding soil is fairly clay-like)...and the polymer keeps absorbing that moisture and never drys out completely. There's never been any movement in the patio but I believe it's "damp" enough, at times, to keep the polymeric sand "gooey."

...this is my theory.