Insulation Under Hardie Siding

February 13 2013 exteriors insulation air sealing siding.

Insulation under hardie siding.

When it comes to siding insulation is important. Moisture can get trapped between the siding and the foam leading to paint failure and causing clapboards to cup and curl. 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.

Exterior rigid foam w modern hardie plank siding details. Method 1 james hardie siding installed directly over continuous insulation c i and other non nailable substrates e g. James hardie is the world leader in fiber cement siding and backerboard. In the end the decision to install house wrap under your siding is a personal one that you should make after discussing it with your contractor.

Well call me half hazard. I m an architect in wisconsin climate zone 6b and am planning to build a 300 s f. However if you re interested a residing project offers the perfect time to examine your home s weather barrier and exterior insulation and improve it if need be. We ve been providing a better way to build for over 100 years.

Of course i did this all knowing my warranty would be void. Last year i installed lp lap smart trim shingles and the 4x8 sheets of lp with batts all over 3 of continous xps foam using fern strips. 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. Over the span of a year a good siding material can save you thousands of dollars in energy costs.

And other non nailable substrates e g. The insulative capabilities of our three siding materials are as follows. I did use larger diameter ring shanked nails than specified to fasten the. According to my calculations if i want to use rigid foam insulation on the outside of the 2x6 walls with r 21 fiberglass in the wall cavities i need at least r 11 25 in order to avoid condensation on the inside.

The building codes are all headed the way of requiring exterior rigid foam the 2012 iecc will require 1 2 foam to boost overall. Addition to my house. 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. How to install rigid foam under siding.