Plywood Beneath Metal Roofing?

September 4, 2009 | Filed under: Misc, Roofing Answers, Roofing Installation

Q: We are getting estimates on replacing the tin roof on our house. One contractor has given us an estimate with a plywood sheathing base under the metal and another without. He said that adding the sheathing would enhance the wind resistance and leak resistance of the roof. (We live in southeast Louisiana.)Another contractor has given us a price without sheathing as he doesn’t believe it’s necessary. What would you recommend??

A: On residential applications experience has shown me to always have solid decking (plywood sheathing) in place.

In your case with an existing house that does not have decking but has a metal roof, and things have been okay, someone might argue that if it didn’t need decking before, why should it now? The issue is that, as time goes on, we tend to remodel our houses and do things to them that make them more airtight. As this happens, more moisture that originates inside the house is typically found to be migrating into the attic. In the case of a metal roof without decking, excessive attic moisture will result in condensation. That is not good.

So, in the best long term interest of the structure, I always suggest decking on residential jobs.

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.

Leave a Reply

Your email address will not be published.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

what's the real price

How Much Should a Metal Roof Cost?

Get My Answer

Before You Call a Roofing Contractor

dial cellphone

Unfortunately, most roofing contractors come in, measure, and simply give you a price. Learn more about what you want and what you need in a new roof, before you invite the contractor into your home. My Roofing Profile Selector is easy to use, and it will help you find the very best roofing solution for you and your home.

Get started