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GreenGoddess User is Offline

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Posts:4

08/03/2008 12:55 AM
I have seen the Hardibacker siding which looks like conventional siding but I want to know just simple flat hung hardibacker used as exterior siding is acceptable. Aside from looking "cheap" I question that you just hang it like drywall as an exterior finish especially in a climate like the Northwest. Do you have to do anything special? Treat, etc or will that last as is?

Dave F

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Posts:3

08/05/2008 11:37 PM
Hardibacker is not rated for outdoor use - at least not as a tile backer. I believe the issue is freeze/thaw damage - which may not be a problem in your climate. My concern with fiber cement siding is permeability - the raw material soaks up water like a sponge. You would want to be careful about sealing (proper painting) the surface and edges. A building scientist from the NW told me that he has seen instances where the bottom edge of fiber cement lap siding was not well painted - water soaked in - and when the sun hit the surface vapor drive pushed it in to the sheathing. The result - rot. If I were installing fiber cement in your climate I'd being doing it as part of a rain screen system. Dave

ReadyToRetire User is Offline

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Posts:173

08/06/2008 4:19 PM
Dave, The Sept. 2008 Fine Homebuilding has an interesting article on "factory-finished siding: a paint job with a 25-year warranty." The author suggests that its available as a service through the siding vendor and can be either stock or custom colors. That then leaves the cut ends to prime and paint -- but they're out of the sun. Larry

Dave F

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08/06/2008 5:29 PM
Larry, You are correct about the pre-finished fiber-cement siding - and the need to follow the mfg's installation instructions by sealing cut ends. GreenGoddess was asking about HardiBacker - a tile backer board that is not normally used as siding and does not come painted or primed. Dave

GreenGoddess User is Offline

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08/06/2008 9:41 PM
I know about the pre finished siding.. this is not that.. it seems to be well hardibacker used as siding.. I could be wrong but I can't find anywhere or info about that... it just seems "wrong" and in the NW to use that without even a paint.. I just have a bad feeling about this choice.

Dave F

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Posts:3

08/07/2008 12:05 AM
Greengoddess - is this detail (raw HardiBacker as siding) something you plan to do - or something you have seen others doing? It's a bad idea - not because the fiber cement will deteriorate but because moisture will get behind it and rot the sheathing and framing. We're not talking about leaks at the seams - but moisture passing directly through the material because it's porous. There are fiber cement siding materials that comes in 4x8 sheets - but even that would have to be painted - not to protect it but to protect what's behind it.

ReadyToRetire User is Offline

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08/07/2008 8:02 PM
Ooops. Not even a close but no cigar. Larry

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