Rafter Tail Removal for Home Performance Upgrade – GWC Mag

This old farmhouse is typical of those built in the 1800s in Upstate New York. Its character is enduring, but when our clients bought it, the windows and doors, siding, and roof were all in need of replacement. It’s a timber-frame house with the siding nailed directly to the studs. There was no sheathing or water-resistive barrier (WRB). The roof had the original plank sheathing nailed to the rafters, and at some point a metal roof had been installed. The interior has original wide-plank wood floors and all the character you’d expect from a house of this age. The clients were looking to maintain that farmhouse charm inside, but the exterior needed new siding, new windows and doors, and a new roof. The results of a preliminary blower-door test easily exceeded 10 ACH50. This building clearly needed some air-sealing.

Farmhouse before, farmhouse after

Adding thick exterior insulation can make for a roof with a thick fascia and awkward trim proportions. Cutting off the rafter tails helps in two ways. It makes it possible to have a continuous air barrier from the wall sheathing to the roof without finicky details, and it allows the builder to shift the entire cornice upward to maintain the correct proportions.

We love the idea of deep energy retrofits but are keenly aware that they do not typically pay for themselves in energy savings. We smile when a project comes across our desk that has a large enough scope of work that energy upgrades are easily implemented as part of the larger process. We have found that to be the sweet spot, allowing us to achieve big performance gains at a low cost.…