Poly or resin joint sand
I had a patio installed 2 years ago and after the first (Chicago) winter there was some serious frost heave. Raising AND sinking. It was built on a standard open grade base behind a 12" retaining wall. The guy put in traditional poly sand, and that held its form, but since the pavers moved so did the hardened sand.
Should we be using poly sand since its nonpermeable? Or a permeable resin based product since the joints are wider?
u/Adventurous_Goose145 — 7 days ago