I just finished inspecting a 1600 sqft house with a hip roof. The roof was metal and I could see light in the attic at the ridge so I know there was some ventilation there but the ridge was only about 20-25 foot long. The house also had ample soffit ventilation and the attic was not extra hot for Alabama. No fungal growth was visible in the attic but the metal roof was only installed about a year ago. The roofers to the owner that they always take out any passive vents when they install a new roof. (That didn’t sound right, I think they were too lazy to cut the holes.) Is this considered adequate ventilation?
Figure it up. Needs to be at least 12 square inches of clear vent per 150 square feet of ceiling. At least 50% needs to be upper venting. Not enough info or I would have figured it up for you.
How does that formula work with a 8/12…9/12. …10/12 roof? Seems it would be cubic feet as the roof gets steeper the air exchange requirements do so as well? This is a question not a statement as i do not say if the ventilation is adequate or not… Not my call as i see it.
George,
I thought about that same question. I came to the conclusion that with that the steeper the roof, the more the vertical distance and the greater the draw, kind of like a tall chimney pulls a lot more air. So that’s why it is halved when there are top and bottom vents.
George not sure about Kentucky but here’s what Indiana’s SOP states:
(l) Insulation and ventilation requirements are as follows:
(1) Licensees shall:
(A) inspect:
(i) the insulation and vapor retarders in unfinished spaces;
(ii) the ventilation of attics and foundation areas; and
(iii) the mechanical ventilation systems; and