[djs26]

I have a 1928 house with the original insulation mat in the attic. A portion of the attic has been floored over with plywood. I was thinking of pulling up the plywood and adding layers of polystyrene sheets for increased R value and then putting the plywood back over the XPS to maintain surface to store stuff on. Is this a feasible solution?

 

[Gary in WA]

Welcome to the forums! I would not use the attic as storage. Gary

 

[joecaption]

That would also form a vaper barrier on the wrong side which can trap moisture and cause mold.

 

[Gary in WA]

If you must, and in a heating climate: pp. 24 and read the article, air seal first, etc.; http://www.buildingscience.com/docu...aluation-two-advanced-weatherization-packages

Gary