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TOPIC: Installation

Do I need Plywood under my metal roof?

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I'm about to replace my old cedar shake roof with a new one. If I can afford it it will be standing ridge metal (Westform Pro Lok 16 inch 26 gauge is on the offers). The offers vay wildely, the cheapest one has no plywood under will just put in UDL 30 Titanium, in the strapping. Should I be concerned inatalling without plywood under? I'm mostly concerned about Noise, it rains from October to April here very hard, other tings I should be concerned about?
Andreas Berglund

8/20/2011
I do not recommend residential installations without decking. Doing so dramatically increases the potential for condensation issues. Todd Miller
Todd Miller
Isaiah Industries, Inc.

8/20/2011
Thank you for the valuable answer. So the UDL 30 Titanium won't deal with the possible condensation issue? Any concerns about increased noise? BTW The roof is NOT vaulted celing it has an attic with insulation. Thank you for answering
Guest User

8/21/2011
The concern we're dealing with here is condensation from moisture that originates inside the house. While a vapor barrier behind the ceilings would be helpful, underlayment is the wrong place to provide control against such moisture. Sure, a lack of decking can also mean increased rain noise though if you have insulation and attic space it shouldn't be too bad. Todd Miller
Todd Miller
Isaiah Industries, Inc.

8/21/2011
Thank you, for your kind answers - it has been very helpful!
Guest User

8/21/2011
Seal up the building envelope at the attic floor level to mitigate any moisture and condensation issues. See the attached picture. Eric Novotny
Eric Novotny
An informed customer is the Best Customer!

8/21/2011

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