Hardi Backer for exterior applications


New member
Aug 26, 2010
This is a quote from Hardi backer faq on thier site. "In accordance with National Evaluation Service Report NER-405, HardieBacker board is recognized only as an interior substrate."

Do not recommend Hardi Backer for exterior installs you are giving bad information.

I hate to see people miss led. Professionals should know better.


Well-known member
May 13, 2009
Topeka, KS
That is funny, Hardi backer makes siding that looks identical to the Board except it's about 1'x8' or so. I sold flooring at a national home improvement store. A guy bought a bunch of siding for his floor tile project, because it was much cheaper. I still wonder how his money saving project turned out.


LifeTime Supporter
Jan 21, 2011
Riverside, CA
You can buy 4x8 Sheets of the Siding Material. It comes with a 'stucco' finish and you can get it in a bunch of colors.

Hardie isn't going to warranty your home built BBQ anyway.

Someone should be able to find the exact makeup of the "Backerboard" and the "Siding" and I bet they are just about the same.