Semester in Sustainable Design - Progress Report

-Written by Shannon

November 26th. Two weeks to go. Time is running low but with things moving so fast let’s take a look back at how we got here.

After completing the floor in mid-October we’ve been moving quickly. The next step was raising the south wall, which we framed out of 2x6s and a strong header since it will be holding a significant amount of weight. To create our newly designed roof, we created a series of trusses which we lifted into place- one end landing on the northern edge of our platform, the other landing on the south wall.

Once those were secured, the next step was attaching Zipboard for the base of the roof. The Zip system is quick to install as it acts as both structural sheathing and housewrap. To install, two of us climbed a series of scaffolds and moved each piece into place, nailing it down and taping the seams to prevent leaking. The next step after that was to add strapping, which is thin strips of wood which run horizontally along the roof. The strapping is mounted to the Zip system by a series of small blocks which are positioned so that the screws will sink into the rafter below. This system of strapping is important so that when the roof goes on it is slightly elevated from the Zipboard, leaving an air gap so that any excess moisture or rain can escape.

Once those were secured, the next step was attaching Zipboard for the base of the roof. The Zip system is quick to install as it acts as both structural sheathing and housewrap. To install, two of us climbed a series of scaffolds and moved each piece into place, nailing it down and taping the seams to prevent leaking. The next step after that was to add strapping, which is thin strips of wood which run horizontally along the roof. The strapping is mounted to the Zip system by a series of small blocks which are positioned so that the screws will sink into the rafter below. This system of strapping is important so that when the roof goes on it is slightly elevated from the Zipboard, leaving an air gap so that any excess moisture or rain can escape.

Once electrical was in it was time to insulate. In the walls we used Roxul batt, which is a product made from spun rock. Installation was relatively simple: cut pieces down to size, create a slit for wires to tuck into, and fit the piece into a stud bay. We chose to use Roxul for a variety of reasons, some of the most important being efficiency and ease of installation, what it is made of, and its safety while handling.

For the roof and floor we chose to use dense pack cellulose, which we chose for its price, insulation value, product make up, and safety. Installation was a more challenging process, as we had to install insulweb (a kind of fabric mesh which holds the cellulose in the roof bay) and add strapping so that the cellulose wouldn’t bulge into the space too much. To install, the cellulose was run from a truck in the driveway, down the hill in a long tube which was fed into the floor and roof cavities to blow in the cellulose.

The exterior of the building was covered in a type of housewrap called Slicker HP, which helps to shed water and keep the building dry.

Now we’re racing to get final projects done- adding window trim, installing the siding, drywall, and floor. Two weeks to go, let’s see how far we get.

 

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