Roofing/Metal roofing


I just had a metal roof installed on my cottage. They left the old shingles on roof & fired it out with 1x4's. They did not use any plastic, the guy said since I had a roof vent installed no plastic (vapor barrier)was needed. Is there any need to be concerned now that it's done & if so, what to do?? I'm asking because I heard of another installer using a bubble wrap under the metal. I just don't want a mess in a few years & correct it now, if needed.

Thanks John.

First of all, here's an article I have written on removing the old shingles or not:

Next, here is an article on whether battens are necessary:

Finally, in my opinion, the International Building Code would have required underlayment, not necessarily a vapor barrier, on top of your existing shingles.  However, not everyone interprets the code that way and there are many installations like yours.

The good thing is that with your roof on battens you do not have the old shingles rubbing against the back of the metal roof.

As long as you have good attic ventilation, and perhaps even if you do not, I think you will be fine with your roof as is.  I do not anticipate any problems.

Feel free to contact me anytime. My email is


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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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