manufacturing and assembly process. Using the  Spruce and White Pine logs, the panels are bolted together with foam  backer rods and ready for insulation. This system allows for exterior walls  to be erected within hours of the sub floor being in place, dramatically  reducing labour costs. A cross-section of the Highland Homes panelized  log wall system illustrates the different layers that make up this system:  Four by six inch kiln-dried logs,  pre-drilled and stacked. Our tongue  and groove logs include a foam  backer rod and are bolted  together. Next is two inches of rigid  insulation then building paper for  weather protection and finally,  Highland Home's six inch ship-lap  log siding.