Roof Ventilation

Originally Posted By: sbyrnes
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Anyone know the approx SF for ventilation in respect to the SF of the attic area?



All Corners Home Inspections, Inc


Serving Pasco, Hernando, N. Pinellas & N. Hillsborough counties

Originally Posted By: mboehmer
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Attic ventilation – Total net free ventilating area shall not be less than 1 sq. ft. for each 150 sq. ft. of the area of the space ventilated. (IRC 806)


Originally Posted By: Dan Leleika
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mboehmer wrote:
Attic ventilation -- Total net free ventilating area shall not be less than 1 sq. ft. for each 150 sq. ft. of the area of the space ventilated. (IRC 806)


I do believe that is 300 sq.ft and not 150 sq.ft and that would be floor area in the attic. And Twice the amount of vent area if louvers are present.

It is a crawlspace without a vapor barrier that needs 1 square foot of free vent for every 150 sq.ft.


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A. Dan Leleika
A-Team Home Inspections
dan@a-teamhomeinspections.com

Originally Posted By: Monte Lunde
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Dan, mboehmer


Let see IRC 806.2 says 1/150th of vented area OR 1/300th if 50% to 80% is >3' above eave vents OR vapor barrier faces conditioned space. So I would say that you both are right and both are wrong. I think that when a code is quoted, then use all of the code not just the part that fits your opinion.

sbyrnes

Spent less then $20.00 and get a code check book, it answers a lot of questions.


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Monte Lunde CCI, CCPM, CRI
Viking Construction Services Inc.

Originally Posted By: sbyrnes
This post was automatically imported from our archived forum.



not looking for code requirements since I’m not inspecting it for code. I’ll leave that to the county inspectors. Just need a rough idea of what’s usually required.



All Corners Home Inspections, Inc


Serving Pasco, Hernando, N. Pinellas & N. Hillsborough counties

Originally Posted By: Monte Lunde
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For a Rule of Thumb, I would use the 1/150th then, it is the same as a crawl space.



Monte Lunde CCI, CCPM, CRI


Viking Construction Services Inc.