This week we look at the internal wall assembly of our “green church” renovation. If you have just caught this article and wish to see the project from day one, go to to view our progress. In response to a number of inquiries, “Yes,” an open house will be held in the fall and everyone will be welcomed in to see the final result. It should be worth the trip to enjoy the fall colors, some cider and a chat with both of us, as well as the members of our crew who have taken this sustainable project to heart. We have a younger team and I am impressed with how they have grasped the importance of understanding how to make a difference in an older building.

   It was decided, as noted in earlier columns, to create an entire internal wall assembly to support an extra layer of insulation; a combination of Roxul and enclosed cell foam. Coupled with the existing wood chip insulation, we expect to bring the external assembly to an R 34 on the wall and to an R 40 on the angled portion above that. The difference here is that the angled portion is actually a wider frame assembly than the walls, hence the additional “R” factor.

   We began by setting a laser on the walls to see how out of plumb they were and found ourselves amazed at how level they actually were. We expected to have some considerable shim work to bring the walls in line, but, fact being, it took very little and in some areas, none at all.   Next, the floor channels were set with a string line, after which installation of the 12 foot high metal wall studs began. It was quickly learned that the use of levels with a magnetic side to them aided in the speed of assembly. Because this is a non-bearing wall system, the original wall was used for additional support and using round head particle board screws gave us a more stable wall, given the 12 foot height.

 After one wall of experimenting and noting that the steel studs have to be checked every 2-3 feet for level, 

Spar and John quickly picked up speed and all 140 feet of wall  assembly was installed in just over a week. No small task working off scaffolds and checking every stud at 2-3 foot increments. Getting the studs as close to plumb as possible is critical to holding the Roxul insulation firmly in place.

    The angled ceiling portion proved to be a little more of a challenge. The decorative trim was removed and we found that these angled sections have settled over time. After some discussion, it was decided to follow the line rather than shim out, as shimming would have created a considerable air space between the metal studs and the wood ceiling. The most time consuming part was creating the custom metal frame around every window. We were all amazed at the unbelievable skill of the carpenters who built this church. Incredibly, working with the tools of the day, all seven windows were within a quarter of an inch to square in the frames, 120 years on.

    Once the wall frame was up, I researched and found an excellent low pressure spray foam.  The area between the base of the floor plate and the old plaster wall was carefully filled. The removal of the wainscot left a void at the base that needed to be air sealed, as well. John then slowly ran a bead of urethane seal along the outer edge of the metal floor plate, completing the air seal of the base.

 In the frame of the windows, we soon realized that in order to get a “buck” opening, (more on this in future columns) the upper section would have to be separated and this meant that there is a small frame area that would be better foamed than trying to fit Roxul, so John carefully applied the foam in three applications to get a full foam infill.

    As we were finishing the walls, the electrical crew from Phase One Electric, one of our supporting trades arrived, and three skilled electricians installed the BX cable for the interior circuits. This metal clad wire, unlike regular romex, which cannot be used in metal studs without plastic protectors, is the best way to wire metal studding. Wood spacers were made up for the boxes and the electricians carefully wrapped the boxes with 6mil plastic; the first step in our complete air barrier, which will be done after the insulation is installed. All three of these young men quickly grasped the concept of this project and the importance of care in the air seal around the boxes.

    The project is moving forward nicely; we are just a bit over budget due to some unexpected demolition costs, but not unreasonably so. Once the plumbing is roughed in and the inspections are done, the insulation work is next.