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TOPIC: Ventilation

Metal Roof over Old Bermuda Roof

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We have an older Bermuda roof (2'X 8' plywood, overlapped). There is some rot on the old roof in various places. Can we install a metal roof over top without removing the old roof and expect a ridge vent to effectively dry out the old roof underneath? Also, would it help to drill multiple holes through the old roof to improve airflow up from soffits, through roof and out ridge vent?? thanks -Ed
Ed Sanden

10/30/2006
Rot never goes away. You can dry it out but the moment it gets any moisture it comes back to life. Next comes the building codes in FL. If you are in a high wind area, they require that the sheating be a certain thickness with fastening requirements. Check with the local building department. My recommendation would be to remove the old roof covering and install new to the code. Chooses a metal roof system that stands off the decking and vent the air space at the eave and ridge. Choose a light colour and combined you will save big on your energy bills and have a home that is a lot cooler in the summer months.
Allan Reid
Dura-Loc Roofing Systems, Inc.

10/31/2006
Thanks. btw, do you know how long "peel and seal" the black tar paper like stuff can last exposed to the elements before the final roof material is put on top? Will the peal and seal deteriorate over time? quickly? thank you.
Guest User

2/4/2009
The time you can wait until installing the panels depends on the brand of peel and stick. Some recommend immediate installation, while others say you can leave it on up to 6 months before putting down the metal. Check with the manufacturer of your particular peel and stick.
Nate Libbey

2/4/2009
Thanks Todd Miller
Todd Miller
Isaiah Industries, Inc.

2/7/2009