Being that the roof is one of the most critical areas of the house envelope in terms of heat and energy loss, the insulation detailing is of extreme importance in the overall performance of the ELEMENT. The roof insulation is also made of polyurethane and is beneficial for several key purposes: One, roof penetrations can be more adequately sealed and insulated to avoid rapid heat loss when compared to standard practices. Two, rain, snow and other debris is much more easily displaced when compared to a standard flat roof system. Three, the obvious shape for filtering water and other debris off the roof is also the optimal location of insulation. More precisely, heat and energy loss will occur through the roof most rapidly at the corners where the roof meets the wall.
Roof parapet without insulation
The 2 x 6 studs used in the exterior walls also provide several advantages when compared to standard construction practices. For example: a 2 x 4 stud (actually measuring 1.5” x 3.5”) provides only 3.5 inches of depth for insulation and the studs need to be spaced at a distance of 16 inches on center (in other words, measuring 16” from the center of one stud horizontally to the next stud). However, using a 2 x 6 stud (actually measuring 1.5” x 5.5”) provides two more inches of insulation depth and the studs can be placed 24 inches on center. This, on average, leads to a 5% increase in insulation. In other words using 2 x 4 studs spaced at 16 inches on center, on average, 12% of the insulation area will be lost to the studs. Whereas, using 2 x 6 studs spaced at 24 inches on center, on average, 7% of the insulation area will be lost to the studs. As mentioned in the posting “Construction Progress: Week of Mar 11” this loss of insulation area can be reduced to almost nothing (on average 1% - 2% because of support needed at the corners) using Structurally Insulated Panels (SIPs).
This week came to an end with the professional insulator coming to the construction site. All three modules were pulled out from the warehouse so that the insulation could be sprayed out in the open air and also so the process could be viewed by the interested public. Unfortunately, rain put the insulation installation on hold after only a portion of one module could be completed. The insulation should be completed by the end of next week.