I'm looking for information on rotting sheathing around windows where self adhered flashings (SAF) are used. I've heard of this on a few projects I've had some proximity to and could swear I've seen information online, but I am coming up empty handed. Can anyone point me in a good direction?
The latest project this happened on had the following wall assembly:
Interior to Exterior:
Latex paint
1/2 gypsum
5 1/2" studs filled with dense packed fiberglass
1/2" OSB
Tyvek Drainwrap wrapped into rough opening
Finned Vinyl window
~6" wide Peel and stick (unknown manufacturer)
1x SPF trim and horizontal Hardi siding
Project was sided in February of last year. New build was completed in the spring/summer. Project is in the Portland, OR area.
Rot was limited only to areas behind SAF and ate through to interior side of sheathing.
From what building science tells me, the interior relative humidity during the various stages of construction would be drying outward. SAF is vapor impermeable and thus the vapor gets trapped. Add winter environment and the sheathing doesn't get warm enough long enough for moisture to migrate around the SAF.
Thanks for any direction to studies or articles on this.
The latest project this happened on had the following wall assembly:
Interior to Exterior:
Latex paint
1/2 gypsum
5 1/2" studs filled with dense packed fiberglass
1/2" OSB
Tyvek Drainwrap wrapped into rough opening
Finned Vinyl window
~6" wide Peel and stick (unknown manufacturer)
1x SPF trim and horizontal Hardi siding
Project was sided in February of last year. New build was completed in the spring/summer. Project is in the Portland, OR area.
Rot was limited only to areas behind SAF and ate through to interior side of sheathing.
From what building science tells me, the interior relative humidity during the various stages of construction would be drying outward. SAF is vapor impermeable and thus the vapor gets trapped. Add winter environment and the sheathing doesn't get warm enough long enough for moisture to migrate around the SAF.
Thanks for any direction to studies or articles on this.
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