Cheap B&Q decking - how to store and treat

If these are the ones I'm thinking of, we store them at work (I work for BnQ) with a small packer between each board so that it leaves about a 1cm gap to let air circulate. We also keep them about a 4" off the ground covered with tarpaulin. Don't put the tarp on the floor but tuck it under the bottom board so that air can still get between the boards. We generally don't keep any in storage for more than two months but I recommend treating them like you would any normal installed deck which is usually just after the damp season. And you might want to treat them with your desired finish before putting them into storage.

Dunno about storage but get a Decking Installation Tool