Insulated Wall System
The Government of Canada introduced new energy efficiency requirements for houses and small buildings in 2015, which now also include log houses and log cabins. The change in the Building Code demands a minimum insulation value of R-20 for outside walls for any log structure, including cabins and cottages.
Softwood, such as spruce, has a mathematical R-value of approx. 1.2 per inch thickness. The thermal mass of softwood (e.g. spruce) is very high, which means it stores the heat for a long time in its system while it slowly travels through the log. This thermal mass of a 3+ 1/8” thick milled spruce beam is approx. comparable to an R-12 to R-15 conventional fiberglass insulation.
To meet the new energy efficiency demands of the Building Code, we offer our insulated double wall system for a mathematical R-29 insulation value, including the spruce log wall (illustration at left).
Reference: BC Building Code, Part 9: housing and small buildings, Section 9.36: energy efficiency
How It’s Done
The finished insulated wall system has the exact same appeal as the inside log walls, but with an R-29 insulation value. Considering the thermal mass factor of softwood, realistically the insulation value of the outside log wall is between an R-30 to R-35.