Head scratcher.

[Robert Jones]

New construction home. Soffit vents on the north facing side of the home. Roof vents on the south side of the home. One small gable end vent on the west facing side of the home. For some reason, the soffit vents on the south side of the home have been covered up. Am I missing something? I don't think is allows for sufficient ventilation of the attic cavity. Just can't figure out why the soffit(s) were boarded over.

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[Marc]

In my area, 1 SF of ventilation opening in the lower third portion of the attic space is needed for every 300 SF of ceiling area present in that attic. The same amount of opening is also needed in the upper third for a total of 1 SF for every 150 SF of ceiling. I doubt that the house in question has it. Also, those 1st story attic spaces over the garage, etc....are they well ventilated? Do they even have access?

Marc

[Robert Jones]

Hey Marc,

The typical venting requirements here are 1/150. There is no cavity above the garage, however, it does have soffit vents running along the front edge. This is a bank owned special that didn't even have insulation in the attic cavity! And people think that new construction homes don't need inspections. I hear people over and over again say, "but the county inspected it, right".

[kurt]

Don't forget, those ventilation ratios are not based in any particular science or calculative operation. Someone just decided that the 1:150 was about right a very long time ago, so that's what it is.

Every attic should be looked at within it's particular attributes. It looks like this one wasn't.

[Rocon]

The only thing I can think of is if the south facing rake was (lets say) 2x 12 with drywall attached to the underneath side, the bays may not be ventilated. Were the bedroom ceilings vaulted?

[Robert Jones]

The bedroom ceilings were not vaulted.

[Rocon]

You would have mentioned spray foam insulation in the attic, so...

Then the only thing I can think of is if someone read an article about venting that suggested that soffit vents on the south exposure will allow hot air into the vents. So they put all the vents on "cooler sides" of the building. If you draw in cooler air then you have greater cooling ability. But that is supposition on my part wondering what someone did.

So your fall back is the 1/150 venting rule. Does it have enough on the other side’s or not? Mention that it is out of normal standard building practices. Let the builder explain what he did.

[Robert Jones]

Will do. Thanks for the feedback.

[hausdok]

Hi,

The only possible explanation is that osmeone is a moron. They need to add venting to that soffit. The gable end vent is going to trouble. It won't show up now but it will years from now when some home inspector goes up in there and finds the underside of the roof all covered with fungi and explains that a gable end vent will short circuit the proper flow of air from the eaves to the ridge.

ONE TEAM - ONE FIGHT!!!

Mike