Your Roof: To Vent or Not to Vent a Metal Roof

To Vent or Not to Vent a Metal Roof

October 2, 2017 | Filed under: Home Ventilation, Metal Roofing

Venting can sometimes be a good way to get things off of our chest but, when it comes to home construction, venting can be a great way to get hot air and moisture out of our attic. I had a homeowner recently send me this question about how to vent a metal roof:

Q: “I need a roof and would like standing-seam aluminum since I live on the water, on the coast.

The contractors seem divided as to whether we should install a ridge vent or some type of venting, or should the attic be enclosed and insulated? At present, I do not have soffit vents because a prior insurance company told us that would make us more vulnerable to high winds. A local engineer (PE) swears we need to fully enclose it and spray insulation. Two contractors say that’s dumb because it needs to breathe.”

A: There is indeed a real trend toward “conditioned” attic spaces which utilize closed cell foam sprayed throughout the cavity including floors, gables ends, and the bottom of the roof deck. When this is done, ventilation is removed. Metal roofing works well with this because the metal is unaffected by heat not being able to pass through it and enter the attic.

The other option, of course, is a vented attic which requires an equal balance of intake and exhaust vents. In many cases, for existing homes, this is the easier way to go.

Should You Vent a Metal Roof?

Both ways can work well. The question is whether, for your application, one is better than the other. Due to your potential for hurricane winds, I’d actually tend to gravitate toward the conditioned, non-vented attic. Unbalanced ventilation in an attic can contribute to wind damage.

Unfortunately, though, I am unaware of any actual research or study into this question and would love to hear about it if anyone is aware of any!

todd Miller

has spent his entire career in the metal building products manufacturing industry. He is president of Isaiah Industries, an organization recognized as one of the world’s leading metal roofing manufacturers. Todd is currently Vice President of the MRA (Metal Roofing Association) and a Past Chair of MCA (Metal Construction Association). Through his website, he strives to raise the bar on standards and practices to provide property owners with the best possible products for successful roofing projects.

You may pull quotes from this article provided you include a link back to the original article on this site. You may not reprint this full article, or even a significant amount of the article, without explicit permission. To gain permission, click here.

2 responses to “To Vent or Not to Vent a Metal Roof”

  1. Teresa Siebel says:

    We had a metal roof installed at our home. It doesn’t have a ridge vent. Since it was installed we have moisture in our home in the summer months, we live in humid conditions, and have to run a dehumidifier. We recently had the siding replaced on our gables and the contractor installed a smaller, octagonal shaped vent on each end of the gables. A few months later we have noticed that we now have mold in our attic. I believe that though the gable vents are smaller, if we had known to have the roof contractors to install a ridge vent, this wouldn’t have happened. Now we are out a lot of money to have the vent problems corrected and mold remediation costs.

    • Proper attic ventilation requires both intake and exhaust vents. Using eave soffit vents as intake and a roof ridge vent as exhaust takes advantage of natural convective airflow. Gable vents are much less effective. Do you have any intake vents in the attic at all, or just the gable vents now?

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

what's the real price

How Much Should a Metal Roof Cost?

Get My Answer

Sometimes finding the right roofing product is the easy part.

Need help finding a local, quality metal roofing contractor or supplier? I can help.

Find a Contractor or Supplier