We had one last ground prep step, which was to grade out the dirt under the porch, extend the trench we buried the drainage pipe in, and cover it in plastic. We extended the drainage pipe itself and its “sock” and finally covered the whole thing in crushed stone. We need more stone, this was leftovers from the drainage project last year, but it’s enough for us to continue work. We want to put the posts on the footings we just poured, but before we can do that, we need to be able to brace them with some framing. That means attaching the ledger to the house.

First ledger board

We’re installing two inches of rigid polyisocyanurate foam on the outside of the sheathing to improve the R-value, reduce thermal bridging, reduce the temperature extremes the wood has to endure, and as an alternative to making the interior smaller with additional wall thickness on the inside. However, this adds complexity to how things like windows and the porch are constructed. The porch is attached to the house with a “ledger”, a board that is attached directly to the framing of the house with lag screws or bolts. Because of the exterior insulation, we need to attach this ledger a bit differently.

“Subledger” in progress
“Subledger” installed and wrapped

I referenced this image from Green Building Advisor which covers this, but it suggested using blocking around the bolts with aluminum flashing over the blocking. That was a bit more involved than I really wanted to get, so instead I built up two layers of pressure-treated 2×10 boards, sort of a sub-ledger. I installed the house wrap over this, wrapping tight to the boards so that the foam can sit directly above them. Keeping this inside the house wrap ensures that the drainage plane behind the foam doesn’t trap water against the house and instead channels it down and out. Wrapping a solid board is a lot easier than flashing around a block protrusion at every bolt hole.

Ledger attached

Since the ledger was being attached to the 6×8″ rim board through 4½” of lumber and another ¾” of sheathing, I used 12″ Spax structural screws. Around the bay, there was just a regular 2×10 rim board with brick behind it, so I used twice as many 6″ Spax lag screws. Sarah’s dad, Mike, helped me install the 2×12 ledger. With the ledger attached, the next step is the columns and the floor framing.