Insulation Under Hardie Siding

I ve become a big fan of utilizing outsulation on all my houses over the last 2 3 years.

Insulation under hardie siding.

The insulative capabilities of our three siding materials are as follows. Exterior rigid foam w modern hardie plank siding details. My research seems to indicate that the foam board product is waterproof. Would it be better insulation if i remove the celotex and use a 1 foam board instead.

Of the three materials reviewed james hardie has the worst insulation. Method 1 james hardie siding installed directly over continuous insulation c i and other non nailable substrates e g. 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. 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.

Hardie plank recommends a maximum of 1 of foam board celotex type material under their lap siding so the 1 2 foam and 1 2 celotex would be fine. The building codes are all headed the way of requiring exterior rigid foam the 2012 iecc will require 1 2 foam to boost overall. The insulation is then behind the tyvek. When it comes to siding insulation is important.

How to install rigid foam under siding. Over the span of a year a good siding material can save you thousands of dollars in energy costs.