Blocking is endless

This deck design, with its clever angles and "picture frame," is a blocking hog. It's never enough for this deck.

Basically, with a bunch of parallel joists 16" on center, you lay the deck boards perpendicular to the joists and you're done. The ends of the deck boards rest on the outer, or rim joists. With my deck, I started adding blocking (mentally) last week, because I was imagining what that "picture frame" would rest on. Across the front (south), the joists support the frame every 16", so the frame is just like a deck board. On the sides, however, the frame needs help, so I installed blocking every 16".

Stupid me. I failed to consider that the deck boards need to land on something at each end. More than that, in theory--they can't just land on a half a joist. Sheets of drywall or plywood sheathing do that all the time--they end on the centerline of a framing member. But I'm using hidden fasteners (for the deck boards) with a center screw that wants to be screwed to the center of a 2x joist. That's where the fru-fru angles really make things tough.

The deck boards (purple) rest on the half the joist, but we need a sister joist to mount the hidden fasteners.

Next to the stairs, my weird 14-degree deck boards are left in mid-air, and blocking to support them will have to contend with the Simpson DTT1Z.

I'm handling the picture frame miter just fine, but not the deck boards.

Remember, we want the deck boards to use the hidden fasteners except for cases like at the house. Things would be easier if we could just use exposed screws, which is how we'll attach the picture frame. I don't think we'll need another block to handle the picture frame miter where only a corner is supported, but I'll reserve the right to cut a quick 45-degree block if it feels needed. (Just looking at the marked up photo, it looks needed.)

The final problem area is the west side.

The existing blocking supports the picture frame, but new blocking for the deck boards is required

In the west side case, the new blocking (in the two voids behind the girder) needs to ignore the picture frame and be solidly under the deck boards. Say it with me now--the hidden fasteners don't like to share a joist.

Did I factor in the need for this many linear feet of 2x8? Of course not.

To end on a positive note, the joist tape I found is perfect! TrexProtect tape comes in 1-5/8" and 3-1/8" widths. Home Depot sells the narrow for 35.54¢ a foot (in 50-foot rolls) and the wide for 80.26¢ a foot. (I think Trex is like Bose--they charge a lot to pay for the advertising that makes them so well-known.) Another aside: Dunn Lumber charges 36.76¢/foot and 67.76¢/foot for the wider.

The solution that I found is Nichigo G-Tape. It's 4" x 65' for 46¢ a foot. I used the full 4" on my double 2x8 beams, and then used scissors to cut the remaining 48 feet or so into two, 2" strips. The tape has paper backing, so this was easy. If it was just adhesive, like a roll of masking tape, it would have been a mess. I paid 46¢/foot for the beams, but just 23¢/foot for the joist flashing, and it's 2" not 1-5/8", so it folds over the sides for more protection.