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Roofing/ventilation issue


QUESTION: Hurricane Sandy blew a tree on our roof and we had it replaced.  The roofer suggested we put in a ridge vent although we already had 3 gable vents (one of which opens or closes depending on whether or not the attic fan is on). We do not have much soffit venting, and he did not add any.  
Since the new ridge vent was put it, our house feels suddenly drafty, and the heating bill has gone up tremendously.  After doing some research, I think this is because we don't have adequate soffit venting, and the conditioned air is being pulled out of the residential part of the house and being sucked out the ridge vent. (Our walls, etc. are not super tightly sealed).

When I complained to the roofer, he offered to close up the ridge vent.  Is there a proper way/ best practice for sealing a recently cut ridge vent?  I want to make sure he does it right.


ANSWER: Good question. You're very smart for asking this.

My concern is that warm moist air will rise in the attic and, if the ridge vent is somehow closed off but this air reaches it, it will condense on the underside of the ridge vent metal.

Therefore I would suggest sealing with a closed cell spray urethane foam.

I hope this helps

---------- FOLLOW-UP ----------

QUESTION: thank you for that foresight!! would we be putting the spray foam on the underside--i.e. in the attic--or on top?  also, would we be re-sheathing, and re-underlaying and re-shingling on top?  if so, what would that entail step by step?
thank you so much for sharing your expertise with us!

What I was referring to was foaming from the inside.

I also assumed they would replace the ridge vent with a non-vented ridge.

The other option is to tear off, replace the decking and underlayment, and install a non vented ridge. In that case you would not need to use the spray foam. However, doing all of that would be a major undertaking!


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Todd E. Miller


I am available to answer any questions pertaining to residential (or other sloped) metal roofing. I have knowledge of most available products but I like to approach projects from a "needs" basis and analyze them individually. Additionally, I can answer most questions about building ventilation.


I have worked for a manufacturer of residential metal roofing since 1980. I currently serve as President and have been involved with a wide variety of projects of all types across the world.

I am a board member for Metal Construction Association, Metal Roofing Alliance, the local United Way, our church, and our son's school.

Over the years, I have had articles appear in several trade journals including RSI, Remodeling, and Qualified Remodeler.

I have a B.A. in Communications and have also completed three years of training with the E-Myth Academy.

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