[doityourselfer]

I laid a flagstone patio in the back yard last weekend. Monday after all was laid in place, we hosed it off to clean it good. Tuesday after work, I swept in 5 bags of Polymeric Sand and followed the directions of slowly sprinkling water at intervals.

When I applied the poly to it, the flagstone was dry as per instructions but underneath was still moist in the sand bed. I figured that because the sand will stick to the surface of the flagstone if wet, being damp in the sand bed wasn't a problem.

Well, today which is 2 full days after, some of it doesn't seem too well set up. The surface feels like there is a hard crust and is soft underneath. I went back and re-read instructions and I guess I messed up. It says that everything should be dry and if there is moisture undeneath, the adhesive will rise to the top.

For you pro's who work with this stuff, is there a chance that this will in fact harden up or am I going to have to dig this stuff out and re- do it? If I have to do that, I may just put mortor in next time.

By the way, the product was Techni-Seal HP.

Thanks for any help or advice.

DIY.


Admin edit: This discussion has been included in the site beginner's polymeric sand page.

[bricknblock]

your "screw up" may or may not have been the "moist" soil beneath, but probably not... if you wet the polymeric sand immediately after you had it all installed my guess would be that you didn't wet if for a long enough period...sounds like you have some wide gaps, probably a lot of sand that needs a significant amount of water to be moistened to activate the bonding...if you only applied a minimum amount of water to the point that it appeared to be wet on top, there probably wasn't enough applied to soak through to the bottom layer of the sand...hence, the top layer is bonded as it should be, but that's as far as the water went...the only thing you can do is to remove all the "bonded, or hardened" sand, sweep more polymeric in, and made sure you wet the sand down good...even if it's a little at a time, let it soak down for a couple minutes, and soak it some more just to be sure

[skahuna]

what bricknblock says is true. if your base is sitting wet though the polymer wont set until it can dry. its a great product for pavers and bluestone but in my opinion it doesnt work as good with the wider gaps in irregular