Chainsaw retrofit: rebuilding overhangs
brianvarick
| Posted in Green Building Techniques on
I am considering doing a chainsaw retrofit for a couple different reasons. The main one is continuous insulation but I am also worried about losing almost 4” of my overhang once I add my exterior foam and rain screen. I like the idea of being able to choose how big they are if I were to rebuild them. I am worried that they won’t be as sturdy as the original overhangs, especially if I just extend the roof sheathing instead of having 2x4s sleepers. I would love to hear from somebody who has experience with this on how it went and whether you would do it again. Thanks
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Replies
Brian, don't worry, they are sturdy. At least they should be. I've done ladder-style overhangs with 12" projection, using GRK screws, and it's been fine even in snow country. If your design allows for continuous roof sheathing, that becomes a very strong tension element and the overhang will be rock solid.
Brain - we added the overhangs after the house was sheathed so we could get a nice tight air seal between the wall and roof. The house has 3" of Comfortboard 80 on the walls, but I spec'd 3" 1.5lb density EPS for under the overhangs because I was concerned about compression with snow loads. We attached the 2' deep soffits using GRK 7" GRK lag screws that we embedded in each rafter. Between the raters we used Fastenmaster Thru-Lok fasteners. For the gable end ladders, we used just the GRK fasteners. Those ladders are 12" wide and like Michael said, they should not go anywhere. We even added nailing blocks on the end so we could finish with Azek crown so the the actual overhang on the gable ends is 18".
Very cool! I am planning on Zips for the roof and wall too, so it would nice to get a continuous seal. Have you done a blower door test?
Hi Brian -
If you build ladder overhangs, there is really nothing stronger than a closed triangle; probably less movement or deflection than the rest of your roof.
Peter