How to Acclimate Your Decking
Acclimation is a necessary first step in any deck installation project. Differences in moisture content between the air and the wood can cause new deck boards to contract or expand. If you do not give the wood a chance to adjust to your local climate and weather conditions, this can lead to issues like warping, buckling, or end checking in the completed deck.
To properly acclimate your deck boards and prevent all the problems mentioned above, you must store them in an environment comparable to where they'll eventually be installed. This means they have to be kept outdoors with plenty of space for ventilation on all sides. You would not smother your finished project with a tarp, so don't do it to the decking while it's acclimating, either. If you stack the lumber, make sure to use spacers between each layer to let the air flow around them properly.