Hip & Ridge Ventilation

I’ll preface this by stating this may sound like a ridiculous question, but I have zero roofing experience. I have ridge vents with with about 3,000 sq.ft under the attic. I have soffit venting around most of the house (where possible) and I’m guessing about 38’ of ridge venting. I had a contractor come by to give a quote on the roof who wants to add static vents in addition the ridge vents, which I thought would short circuit the flow from the soffit vents to some degree.

If more ventilation is necessary, is it feasible to add hip ventilation with a new roof install to supplement the ridge venting or is that too much and/or does it negate the ridge vent?

Thanks

No you don’t want to add additional vents when you have a ridgevent.

38’ is a lot of ridge for a hip roof, you have a large house.

How steep is the roof and do you get ice build up along the eaves?

With that much ridge it is probably fine unless it is a low slope, lower slope = less attic volume.

Thanks, I was thinking the same. I don’t know the pitch, but I’d say it’s a moderate slope. It’s not a low slope but also not a steep slope. I’ve never had any ice build up on the eves.

No ice build up,open soffits and lots of ridge vent.
Don’t mess with something that works

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I have to respectfully disagree. I don’t think 38 ft of ridge vent is adequate

Sorry hit reply too soon. I am guessing if you did the calculations you could get more venting by properly placed RVOs. 38 ft of ridge vent is not very much. It’s easy to do the math on it and there are calcs available on line.

Thank you Tileman. Actually, I missed calculated. It’s at least 50ft if ridge (possibly slightly more). I had somehow overlooked forgotten one ridge. Still not sure if that’s enough. I had looked at the calculator online and if my numbers are right, I’m still short approx 120 sq inches on the ridge.

 The previous owner (2002-2010) had very little exhaust ventilation. He had one power vent (not sure how many cfm it moved) but it’s a large attic space. It burned out years before he moved. He subsequently added 3 small static vents over the mbr. When that didn’t work, he bought a 23 SEER Lennox about 4 months before selling (which was good for me). I had the ridge vents installed after moving in coupled with radiant barrier foil beneath the rafters and attic heat has always been very tolerable (whereas before I couldn’t be up there more than 2-3 minutes without sweating profusely). 

I’ve read that if there’s going to be an imbalance, it’s better to have more intake ventilation at the soffit than at the ridge. Is that correct?

What is the ‘free air’ aperture of the ridge vent
What is the ‘free air’ performance of the eaves vents.

Those ventilation calculations don’t take into account attic volume.

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