Surfaces and subsurfaces are on the same team, remember?
Dan Whitmore of Hammer & Hand discusses a problem and solution found when installing the exterior insulation at a Passive House in Seattle, WA.
One of the homeowner's priorities was minimal maintenance. This is the last house they will live in, they do not want paint every 15-20 years. The main siding element will be a fibercement panel with an integral color that will never need to be painted.
Also, the vast majority of exterior detailing is being done in metal.
These materials are less forgiving to variation than wood, so the substrate must be exact. The house is wrapped with three inches of mineral wool for energy efficiency. One property of mineral wool is that it can compress. This can be good, such as where it needs to cover metal hurricane straps, and it can be an obstacle, such as when all the exterior trim is metal.
Hammer & Hand worked with the architect to design a window buck-out system that provides a solid and flat surface for the trim to fasten to and for the mineral wood to butt against.
—Hammer & Hand is a general contractor that specializes in high performance building with offices in Portland and Seattle