I laid a patio earlier this year in my backyard and used polymeric sand to seal the joints between paving stones.
After a few months now, it looks like the ground on one side sunk slightly, and there are very narrow cracks in the polymeric sand joints (see picture).
I don't think the ground will sink any further, but before winter comes, I am wondering if I need to seal those cracks because I wouldn't want water getting in there and freezing, expanding and causing further damage.
How should I do this? What should i use for this?