Most of the deck remodels will require you to remove existing decking material, and then install new decking after the framework is complete. Imagine that the deck you are about to remodel has 2×4 decking material fastened with 16 penny non-galvanized nails. If the deck is more then a couple of years old then you quickly discover that you can not pull out a single nail. All you end up doing is popping off the nail heads, but the rest of the nail stays embedded into the joist. This is not a problem if you are planning on removing all of the joists and installing new ones. But if the joists are sound, and you are planning on re-using them then you will find yourself spending quite a bit of time on every single nail trying to pull it out.
This little trick will save you a lot of time!
Enjoy