Elegant Eaves for a Truss Roof
Cedar rafter tails and trim add a handsome touch to this roofline.
Synopsis: Architect Steve Baczek and Jim Wolffer of Shoreline Builders describe the process of adding an exposed eave to a sing-story, hip-roofed house. To add the eave without sacrificing energy efficiency, the authors used clipped heel trusses designed to drop below the wall’s top plate inside the house to make room for blown cellulose insulation and a vent channel below the roof deck. The article includes step-by-step photos of the cedar eave installation, and a drawing with details of the eave assembly.
Even as we develop more and more standard assemblies for tight, well-insulated building envelopes, there are always some details that require extra thought and ingenuity. Roof overhangs tend to be one of these details. Not only can continuous rafter tails cause a thermal bridge, but they can create a difficult area to air-seal as well. Of course, this all depends on where you locate your air and thermal barriers.
On this single-story, hip-roofed house on Cape Cod, we decided to use the eaves to add some character with exposed cedar rafter tails. Here in New England, eaves are more commonly boxed in with a fascia and soffit. So not only did we have to figure out how not to have this detail be a weak link in the building envelope, we had to figure out how to finish the overhang so the homeowners would be looking up at something more pleasing than the underside of the OSB roof sheathing.
With the ability to span long distances, roof trusses are an affordable way to create an open floor plan, but they aren’t the best option for an exposed eave detail. In this case, clipped heel trusses are used and the rafter tails are applied. Because the rafter tails are sistered to the trusses, the truss designer had to…