Insulating a 100-year-old barn roof
Hello all – My wife and I are in the process of restoring and insulating a 100 year old timber frame barn in Climate Zone 4a.
The barn has a 10:12 pitch metal roof over 1x skip sheathing. With the goal of installing a new insulated roof while keeping the framing exposed to the interior, one suggestion proposed to us is to leave the existing metal in place, and to install vented nailbase roof insulation directly over top of the existing metal. New metal panels would then be installed over the nailbase. The interior would be unvented.
Is this a viable approach or should the existing metal be removed? What additional control layers, details and/or precautions would be important? Moisture and condensation management are my primary concerns.
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