Kerf channel and thermal bridge
I am working through a shed roof design for a small shop and I have always liked protruding rafter tails. Obviously, I know these days they have been entirely eliminated due to the thermal bridging.
I will ask one question though and show a couple drawings. What if one were to cut a deep enough channel or kerf (may not be the right term) along the exterior face of the envelope (in my case, a SIP)? And then, if that channel (all the way around BTW) were filled with a foam of some kind.
I guess what I never understood about thermal bridging is what about the skins of a SIP that protrude on an overhang? I definitely agree that thermal bridges should be eliminated but I wonder if there might be a way to reduce it so that one could achieve an architectural aesthetic (exposed rafters). Also, don’t factor in the labor required to do this… I think it would require a few jigs and a router to achieve the result. Structurally, the SIP can hold its own and I am less interested in using the fake exposed rafters.
Here are the drawings. I know there are a lot of innovative pro’s here so I figured I would throw out the idea.