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I'm looking into buying a new house here in Wisconsin that has soffit vents, ridge vents and some additional static roof vents installed. However, when the home inspector came through he said that combining ridge vents and roof/static vents is a problem because it can cause the air to short cycle and the attic won't vent properly, leaving moisture trapped. He said ideally you should have one intake system (the soffit vents) and one outtake system (the ridge vents).

The builder told me that the reason the static/roof vents were added was because the carpenter had made a mistake cutting holes for the trusses (or something like that, I'm not a handyman so didn't totally understand) and to fix it they just decided to add these roof/static vents over the holes, thinking that it would simply improve venting for the attic.

My question is, is the home inspector right and I should be asking for the roof/static vents to be removed/closed, or is it fine to leave them in?

Inspector's report (ignore stuff about baffles):

Inspector's report

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Your inspector is correct. Air should enter at the soffit, and exit at either roof vents or a ridge vent. With the current setup air could be entering either the soffit vents or the roof vents, and exiting either the roof vents or the ridge vent. Since your soffits are covered with insulation (because there are no baffles), I'd guess that air is entering the roof vents and exiting the ridge vent. This means only the air near the top of the roof is cycling, which can lead to problems with the roof including a shortened roof life.

In my house there were originally roof vents in the roof above my garage. When they did a reroof they switched to a ridge vent, and as you can see they covered over the old roof vent openings.

Covered Roof Vent

On a side note: Inspectors are hired by you, and work for you. They have no reason to lie or mislead you, since they will not gain in any way from it. In fact, you can probably trust an inspector more than a random person on the internet. Seeing how you paid the inspector for advice, while I'm doing this for free.

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  • Thank you for your detailed response. I didn't mean to imply that I didn't trust the home inspector; he did a great job and was extremely knowledgable. I had actually called the top-rated roofer on AngiesList for my area and he said that he wasn't familiar with that issue and he's never had a problem mixing the vent systems. Various Google queries had also turned up a mixed bag of opinions on the issue, so just wanted to check. Also, the baffles were actually there, just couldn't see them from the angle of the photograph (I should have edited the photo before posting). Thanks again! Mar 27, 2013 at 15:24
  • Have you encountered cases where inspector is "recommended" by the seller? I think this is supposed to be illegal. In this case the inspector may try to downplay things due to the side deal he's got going on... Mar 27, 2013 at 16:44
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    I am also a home inspector and unless the soffit vents are blocked, multiple vents higher on the structure are not usually a problem. Since ridge vents often get covered by snow, gable end vents are also added and don't cause short cycling. If the soffit vents are blocked or too small, yes, there will be air flowing from one upper vent to another. But hot air rises, and as long as there is air supply from below, it will vent. The fact that there are vents a few inches below the ridge vents is not going to stop convection from the soffit vents. Mar 27, 2013 at 20:17
  • BTW, your home inspector comments that there are no soffit vents, or maybe covered with insulation. I think that is why he suggested the short cycle. Mar 27, 2013 at 20:22

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