Before you start building your Buffalo deck, the lumber must be allowed to adjust to your local climate for several weeks in conditions comparable to where your deck will be built. A finished deck will be subjected to the weather, and the acclimation process will get the deck boards used to those circumstances. You wouldn't construct your deck in a shed or smother the completed thing with a tarp, so it makes no sense to do those things to the boards. Instead, stack your decking outdoors with spacers between every level, allowing for adequate air flow across every side of each deck board. If you don't allow your wood to acclimate, your deck boards will warp, buckle, and check.