TOPIC: I Have An Existing Metal Roof and Have A Question
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We have a 2,000sqft double-wide mobile home with a 3/12 pitched roof. Interior ceiling have the same pitch, meaning we don’t have an attic, just an insulated gap between the ceiling and roof. A metal roof was installed August 2016 with the removal of the original shingles by a roofing contractor. Since the installation of the metal roof, every summer we experience a greater electric bill, heat entering from the center peak of the ceiling during 80+ degree temperatures, condensation on walls (only walls in the center of the house), and dirt and leaves entering the house between the cracks of the ceiling trim molding (underneath the ridge cap only)
I climbed on the roof and removed the ridge cap to inspect it. I found the metal panels touching and overlapping at the peak without anything to prevent dirt and leaves from entering vented gap (Pictures 2, 3, & 4)
I cut the panels to have a 3” gap for ventilation, installed corrugated vented foam closures under the ridge cap to keep leave out, and reinstalled the ridge cap (Picture 5, 6, & 7). I also noticed the sheet metal was installed on top of tar paper, and not a rubber roofing membrane.
Yesterday, I noticed the heat and condensation issue in the house again. Seems like cutting a gap for heat ventilation to escape didn’t work. I have contacted two roofing contractors for assessment, and both assumptions were that the bathroom fans were venting into the insulated gap between ceiling and roof. Though, the roof have the proper vents for both bathrooms, and the issue happens without the bathroom vents being used. What can be the causing this heat issue and how can I fix it?
Do you have any intake vents at all at the bottom of the roof, or is that possible? Bathroom vents do need to go through the roof, by code. I would search for anything that was done different with the new roof from the original. You have made some positive changes at the ridge though.
Thanks for your response Todd.
I do have soffits along the bottom of the roof, assuming they are the intake vents you mentioned. I have attached 2 photo).
I'm not sure what could had been done differently from the original roof. The only difference to my knowledge was the removal of the asphalt shingles and installation of the metal roof. The original roofing plywood wasn't damaged, which repairs or replacement wasn't required.
From what I have researched, metal roof should have an underlayment or some vapor barrier between the plywood and the metal sheets. If they installed tar paper instead, can this be the root cause of my issue? I am really out of ideas and don't want to pay another $10k for a new roof that may be done incorrectly.
Felt paper is still often used as underlayment. While it is the inexpensive way to go, I do not see where it would be involved with the heat gain. Those are vented soffits. Is there any way you can pull out a soffit panel and see if there is any airflow to the ridge at all, or if there is a way to move around the insulation and create a pathway? What we want is outside air coming in those vents, traveling along the underside of the roof deck, and exhausting out at the ridge, carrying gained heat with it.
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