Experience with Polymerized Sand?

Hey Aladou,

It is not too clear what advice you want. Sounds like you put PS down under the flagstones to a depth of 1 inch. It is also not clear what your goal is. If you want to set the flag stones in PS to secure them, and fill between the cracks? Inhibit weeds?

To inhibit the weeds, first put down some Killzall by Hi-Yield. PS is intended to be installed on a drainage bed system (stone dust, crushed stone, sand. The following is from a PS pdf file (see the reference)

Poly-Sand™ is a polymer modified finishing sand designed to complement and enhance stone paver installation. Poly-Sand™ forms a solid, resilient joint material that stays in place, and provides excellent resistance to weed growth, insect mining and erosion. It will resist scouring caused by sweeping, water rinsing and traffic.

Poly-Sand™ has the ability to expand and condense. This elasticity ensures that the paver joints avoid cracking and are properly filled at all times. It controls erosion, is flexible, self healing, and reduces maintenance....

Poly-Sand™ should only be used when pavers or tiles are installed on a drainage bed system (stone dust, crushed stone, sand). It is not recommended when pavers or tiles are set above a concrete base. Poly-Sand™ is resilient and won't crack under paving stone or slab movement.

See the install instructions - this will help you get the result you want.