Can I install Hardiplank siding over T111?

I plan on replacing the LP siding on the front of the house with Hardi planking and adding Hardi planking OVER the existing T111 on the remaining three sides of the home. Questions: 1 - Should I include a moisture barrier over the existing felt for the front of the home prior to Hardiplank install? 2 - Should I add a moisture barrier over the existing T111 siding for the other three sides of the home? I have been reading various opinions on this topic and hope to generate some conclusion on what is the right choice.


Nichoel Farris

Answered by Nichoel Farris

Auburn, CA

Concept Green

February 26, 2010

If possible, you should remove the T111. It can rot under the Hardi, and there might be additional issues that need to be addressed. Better now than later.

An air barrier is installed on the warm side of the exterior wall.

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