Finishing the Yurt's Roof
Time to Insulate and Cover
The first step in insulating the yurt's roof involves cutting two inch thick foam to mate up to the underside of the plywood roof deck. Lots of careful cutting and measuring, and usually a trim or two anyway before the fit is just right.
Once the foam sections were cut, the next task was to secure them to the underside of the plywood decking in order to insure that no moisture could condense on the underside of the plywood. To do that, Jillian drilled a pilot hole up through the foam and then through the plywood deck.
Jannel observes where the pilot drill comes through the decking, and sends a three inch screw back down the pilot hole.
As the screw comes through the foam, Jillian meets it with a plywood square. As the screw bites into the plywood, the plywood pulls the foam up and secures it tight against the underside of the roof decking.
June 18: Now that the foam is secured in place, we can start the process of making the roof weather proof. The first step is to cover the roof with 30# roofing felt. In order to minimize waste, we're doing this in two passes. Roofing tar is used to afix the bottom edge of the felt to gutter frame, and to seal each piece of felt to the next, and of course, lots of staples to hold the felt in place.
While I was away fetching Vermadise's new contingent of rabbits, Emily did a great job finishing up the application of roofing felt, and I'm pleased to report that with the minor exception of the two foot round hole in the center of the roof, the yurt is now water tight :-)
In the meantime
June's a busy month as by then the ground's warm enough to do some serious transplanting into the gardens, and that involves a good deal of work getting the new plants settled in and properly mulched.
Thanks to the interns, especially Jacki and Jannel, we were able to bring the new two acre loafing pen on line, a happy step forward which allowed us to move the sheep completely out of the lower half of the main garden, and settle them in the shady oaks that will provide plenty of shade for them through the hot summer months. And while we were focusing on the sheep, we took out the time to hand shear the flock.
June was also the time to take Vermadise to the next level, and that involved acquiring and settling in our stock of breeding rabbits, as well as removing the 6 mil plastic covering and replacing it with shade cloth so that Vermadise doesn't over heat on hot, sunny days.
The upshot is that thanks to Emily, work has been progressing on the yurt, albeit slowly, while the rest of us attended to other parts of the system than needed more timely attention.
While we were awaiting the arrival of the special cut metal we'll be using to for the final layer on the roof, Emily started the task of installing two inch thick sheets of foam to insulate the yurt's walls.
Because the foam is flat and the walls are curved, it was necessary to use the batten technique to insure that the foam was pulled snug against the outer wall so that there couldn't be an air space between the wall and the foam. If such a gap were left unfilled, moist internal air could condense on the inner surface of the outer wall and cause problems later on. This way, no gap, no problem.
The metal roofing we're using usually comes formed into sheets with valleys and peaks that give strength to the metal and provide a way to line up each sheet by over-lapping the previous sheet. You can see what that sort of roofing metal looks like a couple of entries back where we're installing brown metal roofing on the new entrance to Vermadise. But pre-bent wasn't going to work in this case not only because our roof is a sloping curve instead of a flat plane like a standard roof, but also because of the rolled edge effect we were going for at the eaves. And so we ordered the metal plain without any of the standard structure and proceeded to cut each piece to fit;just another way this sort of specialty construction is labor intensive. We applied a liberal application of clear silicone caulking between the sheets, and screwed them in place using specialty screws that incorporate a rubber washer to insure a positive seal were the screw passes through the metal.
Mounting the metal roofing is a two step affair. The first step is to cut the sheets to shape and screw them in place, and the second step involves removing a portion of the screws in sequence so that the metal can be lifted up and a seam of silicone caulking laid down before the metal is screwed back into place. Once the upper tier of metal was caulked and screwed down, it was time to mount the flashing for the skylight. Lots of caulk and screws, and the yurt's roof is just about done. The only task remaining involves applying the metal to the dormer over the door.
The last bit was the slowest going, but that's the way these things go; when you're working with something new to you, it's best to do the parts you understand first thereby gaining experience with the materials and tools, as well as whittling the job down to a more manageable size. I'm thinking that we won't actually mount the skylight itself until closer to fall. Instead, it makes sense during these hot summer days to just place a screen over the opening to keep bugs out, and let the natural ventilation keep the yurt cool and comfortable. Well, that concludes this chapter of the yurt saga. Now the work will move inside as we start to work on floor, walls and ceiling.