Keep cartons stored horizontally at all times. Stacking them vertically will damage the click mechanism.
We recommend you store the flooring in an environment as similar to the actual job site as possible (in terms of both temperature and moisture-content). If that's not possible, try to have the flooring in a climate-controlled environment for at least 48 hours prior to installation to allow the floors to acclimate (acclimation). Although our vinyl is made out of virgin materials (and is thus extremely stable), very small movement can occur if moving the floors from an extreme temperature and installing immediately.