Sheathing/Insulation/Moisture/Blocking
rabbitude
| Posted in Construction Techniques on
In the April/May Thermal Bridging article, and in a number of similar articles I have seen, no plywood sheathing is shown i.e. the rigid foam is applied directly over the studs. My project is in a 110mph wind load area. What about shear loads? Also, wouldn’t rigid foam insulation trap moisture in the wall? Further ,how would you block around windows and doors for flanges and trim and is tape or Ice and Water best flashing over the flanges.
Replies
Shear
is provided by e.g. the old fashioned diagonal bracing method. A colleague of mine did it this way. Diag bracing. 1/2" thermax over a 2x6 insulated construction to reduce thermal bridging. Then of course a vapor retarder on the inside and of course ... a good mech ventilation syste (i.e. exhaust fans properly controlled AND installed). He liked being able to locate a stud by poking a nail through the insulation. Don't know if that was truly how it worked or not. As for blocking around e.g. windows ... not sure ... assume he ran a full thick block around the rough opening ... but then his insulation may be hanging a bit; I don't recall if I ever knew about that detail.
Somebody posted this reference in another thread. I haven't looked through them yet, but there may be some info there you can use:
http://www.buildingscience.com/doctypes/primer
Why is it that sometimes the links don't get made "hot"?
http://www.buildingscience.com/doctypes/primer