Insulation Under Hardie Siding

Exterior rigid foam w modern hardie plank siding details.

Insulation under hardie siding. Many houses built today have a double wall type of insulation with fiberglass batts fastened between the studs on the inside and rigid foam board over. The building codes are all headed the way of requiring exterior rigid foam the 2012 iecc will require 1 2 foam to boost overall. My research seems to indicate that the foam board product is waterproof. I ve become a big fan of utilizing outsulation on all my houses over the last 2 3 years.

Of the three materials reviewed james hardie has the worst insulation. When it comes to siding insulation is important. Over the span of a year a good siding material can save you thousands of dollars in energy costs. Method 1 james hardie siding installed directly over continuous insulation c i and other non nailable substrates e g.

The insulation is then behind the tyvek. And other non nailable substrates e g. February 13 2013 exteriors insulation air sealing siding. Gypsum sheathing with combined thickness of 1 inch or less method 2 james hardie siding installed to furring strips that are attached through the c i.

Behind the 3 8 strapping is the tyvek creating an air cavity and drainage plane directly behind the hardie which prevents any moisture that penetrates the hardie and it will from deteriorating any of the other building elements. The insulative capabilities of our three siding materials are as follows.