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TOPIC: Installation Process

Double layer of tar paper.

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Starting with a completely stripped roof, right down to the shiplap. Can anyone see a problem with laying down a layer of 30# ASTM tar paper on the shiplap, adding a layer of 0.5" CDX plywood, then another layer of 30# ASTM tar paper? The issue is the extra tar paper near the house. Thank you!
Guest User

10/1/2004
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I have no idea what you are trying to accomplish with the second layer. Underlayment is designed as a moisture barrier. That is to catch any condensation under the roof covering and to act as a secondary protection. Instalation in this manner could under certain circumstances trap moisture and cause rot.I would not recommend it.
Allan Reid
Dura-Loc Roofing Systems, Inc.

10/4/2004
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