Soffit situation – vented or unvented
vitamin
| Posted in GBA Pro Help on
Zone 2
Phoenix, AZ
Question about soffits—I have a flat roof with trusses that have heels, and the attic will be conditioned from the heel inward.
The eave portion of the trusses will be 2×6 or 2×8 and sit outside the thermal envelope.
Do I need a vented soffit under the eave, or is an unvented soffit an option?
(see image)
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Replies
How will you be insulating your walls?
There's no need to vent your soffits if your roof is an unvented roof as seen in the image. Soffit vents are used to allow air into the attic for a vented attic but since you don't have a vented attic you don't need vents in your soffit.
Thanks. The wall will be of 8x8x16 CMU (Omni Block). The block is engineered in such a way to include thermal breaks and filled with expanded polystyrene inserts.
https://www.omniblock.com/products/#system-eight
Is this “conditioned” in name only?
Will it really have any supply or return vent? Will the temp and humidity be the same as the rest of the house?
With vaper open insulation like rockwool against the roof you will you will need a vapor port
Walta
my bad with the term "conditioned". So yes, "conditioned" in name only. Thank you for the clarification. I should have said "unvented" and within the thermal envelope.