I had a knowledge gap – another big gap that invites driving rain – and plywood from the formwork that I can reuse. How do these voids and sheets fit together? Here you go:
Part of our back porch will be enclosed. That includes the roof access and the basement level. And there are some code issues I had to contend with, namely fire rated walls. The roof access enclosure requires two-hour fire rated walls. The basement level also requires a two-hour fire rated wall on the west side, and one-hour fire rated walls on the south and east side.
I’d never built a fire rated wall, so I had a little research ahead of me.
That other big gap…
… was the currently wide-open roof access. It worried me a little because it allowed driving rain to pour into the porch and part of the south elevation. I needed some level of rainscreen until I figured out how to build those fire rated walls.
From formwork to rainscreen
How convenient that I still had the plywood from the foundation formwork laying around. They were perfect for a provisional rain screen along the north and west side of the roof access. But I first needed to cobble together the framing that would support the plywood, and later the permanent fire rated wall.
No easy framing! Because of the curb on the north and west side, I couldn’t pre-assemble the wall but rather I had to insert it bit by bit.
This was not a perfect rain screen, but good enough until I got to the fire rated enclosure.
Reuse versus new
Not only did I reuse the plywood, but all the framing lumber came either from the foundation formwork or another stack that I had saved.
But I didn’t have that much luck on the door, which was a spanking brand new steel skin door. I had searched the salvage and reuse market for exterior steel doors for a while, but was unable to get my hands on the right products. When I found good matches, they were more expensive than new doors, which also happened to be on sale.
The more specialized or specific the items you need, the harder they are to find on the reuse market.
Last but not least, I would like to thank Angelo and Rubani for their help with the framing and rain screen. I sure was glad to have those extra helping hands!
Building the porch roof followed a now familiar pattern: getting stairs and landings in place, putting up ledger boards, installing joists, covering everything with plywood and installing the roofing system.
What was much more interesting was the staircase extension to the roof level, because it was about the devil and the details. I wouldn’t have minded a little break for the few neurons I have left – some mindless work. SOL!
The roof access extension has a south facing sloped roof. This will be prime real estate for solar renewables. Solar hot water panels should be installed at a 55 degree angle. Photovoltaic panels are more fussy. They like a 66 degree angle in winter, 42 degree in spring/fall and 18 degree in summer.
Now think about these numbers for a minute. This roof could turn into a really interesting art project, making Frank Gehry look pale. But I don’t have a minute, and my neurons are not firing right.
So, how do we determine the roof slope? Not through solar angles, but by the means of dimensional facts. We can extend the roof access by ten feet above the existing roof, and we need to make sure we have enough head room (says the tall German).
End result: A 28 degree roof slope.
Drainage is following me around. It often dominates my professional life, which I don’t mind at all. And in a gravity defying stunt, it was following me all the way up onto the roof – which also has to drain. Surprise!
Whereas previously the entire south edge drained the roof, almost half of that edge is now blocked by the new roof access. I had to make sure we had a tall enough curb to direct roof runoff around the extension. The alternative was to have a waterfall feature cascading down the porch staircase … a charming idea with a lifespan of microseconds.
Redirecting the roof runoff by means of a two by eight, which we set on the roof deck between the two posts, sounded much less adventurous. Good – give boring a chance!
Ease of access was another issue. The options my porch builder and I discussed all involved a rather tall door threshold. The thought of stepping six or eight inches up and through the door generated mental scenarios of tripping and falling onto the roof. That’s not a place where you want to trip.
So, we built a little square landing atop the roof framing to get us to an elevation where I could walk out the door with a normal threshold and step down onto the porch roof. That stepping down seemed less of a tip hazard. Subjective? It is.
This all took some tinkering, because the roof framing has a slope while the landing has to be level.
Our porch builder finished his job by installing the gutters and downspout, and the last heavy duty hardware items. This porch is built so solidly, I could park my truck on it – if only there would be a way to get it up there.
This back porch is a head turner (just ignore the piles of construction materials). Cathy and I are very happy with the end product. Our porch builder, Espinoza Construction was very good to work with, easy to communicate with and Edgar and his crew were always thinking a step or two ahead. We are impressed with the quality of work they delivered. Not only that, but they also put up with me through the entire process, which is possibly their biggest achievement.
A staircase extension to the roof level to access the future vegetable garden and solar panels
… could be as simple as leaving the porch as described above, turning the 1st and 2nd floor level into a screened-in sleeping porch for the dog days of summer, or enclosing each level with operable windows and converting it into an unconditioned three seasons room.
The devil is in the details
Take the enclosed and conditioned basement level, for instance. How do we heat the space, and more importantly, how do we insulate it? But more about that later.
Because the 1st floor porch level will start as an open porch, I will need some level of waterproofing. Simply put, I need a roof over the enclosed basement level. Not only that, I also need a roof over the 1st floor porch level, because I don’t know if, when and how I may or may not convert the 2nd floor to a sleeping porch or three seasons room.
The practical part
The first floor as well as the second floor level was built with a two percent slope away from the building. Once the plywood was in place, we installed a torch down roofing system. That took care of the “roof” we needed at each level.
To accommodate the deck, we installed sleepers that followed the two percent slope, with a depth of half inch at the house and two and a half inch at the opposite end. That provided us a level deck over the sloped roofing.
Any driving rain will drain through the deck board joints and then intercepted by the roof below and drained out to the face of the porch.
We applied the same principles to the staircase landing between the first and second floor, which will allow us to enclose the basement level as planned.
Typical open porches are built without the in-between roofing systems. In our case, it seemed a good future proofing practice to take this extra step.
The old back porch left us with a few holes in the wall – the old joist pockets. Unfortunately, they didn’t line up with the new ones. In preparation for the 2nd floor porch level construction, my first task was to mix up some lime-based mortar, grab some of the leftover common bricks and fill in the old joist pockets.
Because we already had the post extensions in place, the second floor level went up like a breeze, including ledgers, joists and decking. The new back porch began to actually look like a porch, once the railings were installed. It’s curious what a difference such subtle things can make!
We also had some excitement with more post extensions, lapped scarf joints and heavy duty carriage bolts. The two shorter extensions will support the porch roof level, while two really long ones are needed for the roof access level. Those six by six posts weigh a pound or two, particularly if they are still wet from the pressure treatment. I was left admiring the calm and confidence with which the carpenter crew conducted these balancing acts.
And then there were the stairs — the good old stairs with post extensions and all. They had occupied my mind for quite a while.
From long landings to little landings
The stairs in the old back porch made the most of the available space. They had a short flight with four cross steps between the two long flights. The new porch plans called two long flights only with a long contiguous landing connecting them.
The proposed layout would take away 20 inches from the porch deck to make up for the four cross steps that had been eliminated. That didn’t sit well with me. I didn’t see the necessity for a contiguous stair landing, but rather was intent on maximizing the usable porch deck area.
I asked our porch contractor for advice, and he pointed out that we could bring back the four cross steps by adding two more posts. The extra posts would allow for the supporting joists for each of the two landings, one below and one atop the three cross steps.
One of the posts would be anchored to the foundation wall, but the other post would need a separate spread footing down at the basement level. Because I had that discussion early on, I planned for and installed the footing.
We were back to the same stair layout the original porch had, and with it we’ve made the most out of the space available to us. And I am still using that space daily, sitting in my rocking chair, sipping my morning coffee!