When roof protrusions such as eyebrow roofs and porch roofs are installed prior to sheathing or around partial Sheathing they inadvertently allow cold air to leak into the building’s interior in heating months and cold air to escape during the cooling months. When the areas around these roofs are not sealed and insulated, air leakage and moisture reduce the effectiveness of the building envelope.
It’s best to properly seal and insulate while you are installing these roofs rather than trying to plug leaks after the fact especially if a call back is required. You can do so with the following tips:
- If you have a complicated assembly like a rim joist, its best to seal all of the joints for a more energy efficient building envelope.
- You can frame the roof as a stand-alone structure rather than framing the eyebrow roof with small rafter-tail pieces which creates irregular holes which are difficult to insulate and seal.
- Sheathe the wall prior to attaching the eyebrow roof.