Month: July 2017

This was not my finest hour(s). The framing of the first floor of the porch consisted of a few steps: notching and putting up the three columns, adding the front beam, adding the side beams, then installing the floor joists. For starters, my original framing plan was bad. I bought a bunch of double joist hangers with the intention of putting the double 2×12 front beam between the columns on the front. Mike S said that the code requirement was to have the beam span across the columns, and used the back deck of the apartment a couple doors down as an object example of how it was supposed to be done. I was reluctant to do it exactly that way because I wanted the front of the columns to be proud of the deck for stylistic reasons. I eventually settled on notching the columns on the back side to the depth of one joist, then using brackets and through-bolts to hold everything in place. This required additional trips to the store for different (longer) boards, returning brackets, buying new brackets, etc.

Ship-lapped beam

Saturday, Mike (Sarah’s dad) and Rob came over to help me with the installation. I got the columns notched using a combination of circular saw and reciprocating saw. Next, after getting the three 6×6 columns stood up and putting the front beam on, we discovered the center column was closer to the house by a couple of inches, causing a banana effect. We took it back down and wound up cutting off the top of the j bolt embedded in the concrete, drilling in a sleeve anchor (which is not as strong) and securing the clamp much closer to the correct location. Apparently Sarah and I augered the footings even less accurately than I initially believed.

Aligning columns

With the center column back up and the front beam back on, we put the first side beam on and discovered my next mistake. I had carefully measured the height to notch the columns by using my six foot level from the top of the ledger to over the footing and the bracket and measuring with a tape measure. I was careful to have the level just break the line to account for slope away from the house. I somehow must have measured to the top of the level instead of the bottom, because the beam was actually over two inches higher than it should have been, meaning that it was sloping toward the house. At this point, we called it a night.

Columns installed (the first time)

Nicole and Rob actually spent the night so they could help us again on Sunday. We took the beam back down, took all three columns back down, cut two inches off the bottom of the columns (fortunately I hadn’t cut the tops down at all), put them back up, and put up the side beams. Sarah’s parents came back as well and we got most of the joists in place, however, there too we ran into some challenges. We were measuring the lengths as we went and fitting them snugly, apparently as we went it was actually pushing the column at the end out of plumb and a gap formed between the column and the side beam. We had to go back and remove several joists and cut them shorter, and get the column back to level. I went back to the store and got some more Spax screws which I put through the columns and into the side beams to hold them tight. I may add some additional bracing, since I’m still not 100% happy with it.

Rob installing joists

We put the joists on 12″ centers since we’re going to use composite decking and don’t want any flex. I ran into some issues trying to use the front beam as a guide for the top of the joists, since there was variance from one side of the center column to the other. I had to go back and adjust several joists to be higher or lower so that the level slides smoothly across the joists without gaps. Given they were already nailed with joist hangers, this was a bit of a hassle.

Floor framing complete

In short, this was a two steps forward, one step back project that took more time and effort than it really should have if I’d been more deliberate in planning. I want to thank Rob and Mike, as well as Mike S, for all their assistance.

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.