carnett

Why bother with an unsightly and inefficient flat tar roof when you can look out the window at a teeming green garden? That's why I'm turning part of my roof green. I'll post more detail about what I'm growing and the DIY tray-based system I'm growing plants in, but before any of that can happen, the roof itself needs to be prepared to hold several inches of dirt without collapsing or flooding my upstairs. For that, I went with a multi-layer system: insulation, rigid roof board and a thermoplastic barrier.

Building this house has been a constant learning experience, and today was no exception. My original plan was to build the walls from special insulated structural panels from Kama-Eebs, add some simple "X" braces to control shear, and throw on some housewrap before attaching my siding. And that would have been the cheapest and most ideal solution, but the more I looked at the final Kama panels installed the more I began to question the wisdom of that idea.

We recently installed the panel roof system over the kitchen area and hit the first of our inevitable early-adopter glitches. The roof panels are 11 inches thick and much heavier than the wall panels, as they have much more embedded steel to carry both my green roof and the snow load here in upstate New York. The things are dense and required a serious effort for two to carry around. Even with all that beefiness, the engineer asked me to put a horizontal steel beam through the middle of the room for added support. The panels were supposed to meet at the beam and fit seamlessly together. The key words there: supposed to. Read on for the reality.

I’m standing on top of the third floor after a very productive day of putting the Kama Eebs panels and the upper joists in place. When the panels arrived, we had just put them in piles all around my site so it was a bit of work just playing the find-and-seek game to get the proper panel to the correct wall location. But then it was just a matter of gluing and screwing the track into place, spraying foam onto both the shiplap joint and the track and tilting the panel into place. Once you have a tight fit, you screw the track and the shiplap joint together and move on to the next unit.

One of the most unique things about my green home is the walls: instead of a standard "stick-frame" construction, I'm using special insulated panels from a company called Kama-Eebs, which have all sorts of advantages in efficiency and heat retention.

With the first-floor walls poured, it's time to erect the structure for the rest of the house before my panels show up. Does this look a little overbuilt? Well, there's a very good reason why folks don't build flat-roofed houses in the Great White North: It's called snow, and it's heavy. It makes little sense to design a house that would allow snow to sit on the roof, stressing the structure, instead of just sliding off.