How your attic breathes

Your attic spaces need to breathe to get rid of excess heat and

I introduced this idea in Part 1 – Can your attic breathe?

For air to flow through your attic, you need balanced




Two biggest mistakes I see:

Poor intake

  • Not enough soffit vents — Re-roofed a house recently that had 7
    soffit vents. They needed 27!
  • Blocked soffit vents — Usually happens when insulation is blown
    in and soffit vents aren’t protected
  • No intake at all — Some homes don’t have soffits and require
    special intake vents.

Mixed exhaust

  • You only need 1 type of exhaust.
  • If you have turbines, DO NOT add ridge vent without blocking
    the turbines.
  • If you add a power vent, block all other exhaust vents.
  • If you have a gable roof with gable vents, these must be
    blocked when adding different exhaust.

Why all the fuss?

Excess heat and moisture lead to higher summer electric bills,
premature damage to shingles, and a variety of damage caused by
high humidity.

For your Smart Homeowner list

  • Walk around your house and identify your intake and exhaust.
  • Use the vent calculator to see if your ventilation is correct.
  • Still not sure? Shoot me an email. I can help.



P.S. I love power vents — BUT — before you add one, make sure you
have enough intake. The house that needed 27 soffit vents has
turbines. If we went with a power vent, they would need 48 soffit

P.P.S. Inspired by my conversation with Kurtis last night … if
you’re adding blown in insulation, make sure to install baffles
to keep the insulation from blocking the soffit vents.

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