Raised heel on a standard sawn stick?
cutdude2
| Posted in Green Building Techniques on
So it’s a 12 pitch roof with a full dormer. Can we build up a regular sawn stick, (2X10) to make more room for insulation above the wall? I recently saw….(guru, here) saying that we ought to have at least as much insulation above the wall as is in it. The plan is for a 12 inch wall, It is the dormer rafter that I am getting at. Could we make a birds mouth by adding material, rather than the usual removal? Like someone might make nasty to a stringer.
Whattaya think?
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Replies
Dave,
People do it all the time. Put your ceiling joists and a rim joist on top of your double top plates. Then stack some flatways 2x4s at the perimeter of your attic where the bird's-mouth wants to be. You can still put a bird's-mouth there if you want.
Fill the ceiling joists with insulation, and pile it above the top of the joists too, and as high as your stack of flatways 2x4s, and then on up between your rafters, as deep as you want. Leave a ventilation channel under the roof sheathing.
Here's a detail from the GBA detail library that shows something similar -- a raised plate detail using a single 2x6 instead of a stack of 2x4s:
https://www.greenbuildingadvisor.com/cad/detail/vented-attic-siding-cold-climate-raised-plate-asphalt-roofing-fiber-cement-lap-siding-ove
Does this detail work with a non structural ridge board? Or only with a structural ridge beam?