Leave Polymeric Sand Until Tomorrow?
The answer isn't quite straight-forward, but the tarp was probably the best option. When I lifted the tarp, half of the tarp had dew on the bottom o fit--the half still in the shade. So the other half may have had dew as well but dried out before I lifted it. Despite this, the bricks and sand were entirely dry apart from what drips fell when I lifted the tarp and the sand was definitely not activated. Results may then vary I guess, but it worked for me :-).