Decks, Patios, Porches and Docks - Decking pattern, 12 X 20

Building a 12 X 20 addition to an existing 8 X 20 deck. Joists are running out 12 feet, so decking pattern needs to cover 20 feet. One option is staggered 16 feet decking and 4 foot that will provide a nice 12 foot joint free area in the center. I had seen plans for notching a 5/4 piece of decking and installing it horizontal between two pieces of decking allowing a single seam with 10 foot deck boards on each side. I can't find it again. Any ideas.

Maybe I picked a slow week, but no replys thus far.

Lets try another route. What if any concerns should I have if I go with double joists in the center of the deck and but the 10 foot decking together at the double joist.

The seam it would create in the middle would look bad. Go with the alternating 4' pieces on the end. I would also make sure I had the 5/4 stock on hand and that it was actually 20' and not something less. You will lose some when you cut it and it may be short to begin with.

It might be cheaper to buy 16 footers and 8 footers and cut the 8 footers in half. I would also double up on the joists where they will butt to each other or at least sister a 2by4 on and caulk[silicone] the top jointwhere they meet to keep the water out.