[Greenbuilding] Another debate rages on Vapor barrier or not in 8700 hdd

[George J. Nesbitt]

Robert Tom wrote:
> the poly sheet needs to be fully supported to prevent damage due  
> to changing pressures as a result of wind, something that is not  
> accomplished with the 3/4" furring on the interior.
>   
:-) Thanks for making that point, I was also going to. ;-)

> In single family residential structures , moisture migration into the wall  
> materials as a result of vapour diffusion never has been and never will be  
> an issue and two coats of a suitable vapour diffusion-retarding paint on  
> the drywall will adequately deal with the non-existent issue.
>   
Couldn't have said it better myself, but I tried.
> However, in an 8700 HDD/yr climate, an effective air barrier strategy is  
> of paramount importance.
>   
Since almost all insulation materials are not air barriers (rigid PU 
foam the exception), and they work by trapping air, I would say that 
effective air barrier*S* are important in all climates.
> Hanging 1" thick wood siding on 1x4 furring that is fastened via fasteners  
> cantilevered through 2" of styrofoam has not in my experience, been very  
> satisfying.
>   
Can you expand on what your experience has been??

> I would look at pre-fabricating the siding into demountable panels that  
> would be clipped to the building.
>   
The kind of off the wall thinking I have come to respect from Tom. :-)