Installing the Shop Roof
Sometime during the planning of my shop build, it occured to me that if I wanted the interior wall/roof decking to match the framing members, it would make sense to order my decking at the same time that I ordered the timbers. Budgetary constraints being what they were, I was only able to purchase a handful of rough sawn, 16’ long green oak planks for my roofing. This turned out to be a blessing in disguise, as I later decided I prefered the two tone look of pine-on-oak, and I failed to realize just how green the planks I had ordered would be. In the picture below, the planks can be seen going on practically seamlessly, as tight as we could get them. Within weeks, they had shrunk to produce gaps in excess of 1/2” in many places. Had I more than two weeks to plan, order, construct, and raise, I would ordered my decking earlier and allowed significantly more time for it to dry. As it was, I took the advice of another timber framer and was sure to put down a layer of black tar paper over my decking: any gaps that opened up revealed only black.
Layer one: 4/4 oak decking. Layer 2: black tar paper. Layer 3: insulation. A friend of mine who works as a carpenter and timber framer in Maine recently built a similar shop, and told me that with 2” foil faced rigid foam on the roof and 1” on the walls, he could comfortably keep his shop warm through Maine winters with only a small wood heater. Winters in southeast Ohio are not nearly so frigid as they are in the northeast, so I happily went with the same products and trusted they would be sufficient.
I bought R-Tech foam board insulation from Menards and secured it to my rafters using 3” deck screws and plastic washers that keep the screws from tearing through the foam. Light as the boards are, installation was easy, and I finished by taping all of my seams with aluminum flashing tape.
The last step before installing the metal panels was to secure 2x4 purlins horizontally across the roof with GRK structural screws going into the rafters. Working from the bottom up allowed me to use the previously installed purlin as a step to support myself while installing the next one. This is also where my 1’ overhang was introduced, and I made sure that the overhang purlins were secured in at least two rafters.
Decking covered with tar paper and an OSB subfloor installed. My order of sheathing, flooring, and siding materials arrives.
“The Jetson’s” meets traditional building in this modern take on an old classic…
Purlins attached to the rafters with GRK screws. The metal roofing is then secured to the purlins.
The last step was to install the metal roof itself. The panels I ordered come in a fixed width of 3’, with custom lengths: my panels ended up being 10’ long. I also ordered a ridge cap, along with eave and gable trim.
I found the most difficult part of the roof installation to be setting the first piece. As each panel overlaps the previous panel, a little error in alignment on the first panel multiplies itself with each successive panel. I ended up resetting my starting panel three times before I was happy with the alignment, eventually using a large straight edge to held flush to the bottom of the panel to gauge where the following panels would line up. The rest of the installation went smoothly from there. Working alone, I was able to do the entire roof in a day, sliding the panels into place as I climbed the ladder and then securing them with an impact driver and roofing screws (color matched with rubber washers).
