# exterior drywall?



## Gary in WA (Mar 11, 2009)

The plywood sheathing is for lateral restraint on the wall, required per code. The Gyp-board (exterior gypsum board sheathing) was used mostly on apartments around here from 60's-90's. You are missing the builders paper/house wrap required now per minimum code as a second line of defense against water intrusion. If it rains substantially per location and it is a (weather) wall; prevailing wind- IMO, replace and reside with a WRB (housewrap) as the gyp does mold easily. many of pictured Hardi fasteners are too high on the board; http://www.hardieinstallation.com/hardieplank-lap-siding.shtml

Tip; http://www.jameshardie.com/JamesHar...ments/TechnicalBulletins/9-joint-flashing.pdf

Gary
PS. As the top joints are open, water may be molding on the backside of the Gyp-board, repaired many apts. with same- the air doesn't dry it enough as the exterior side and it is papered on both sides.


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## shark_bait (Apr 28, 2014)

Thanks for your insight Gary, this house was built in 81 which at the time, was in a nice country club neighborhood so I'm surprised it was built like this.

I have a few questions on the repair.

OSB or plywood? Let me rephrase, I know plywood is always better but since I will be using a WRB and 6" joint flashing, I just want to redo this area of the house for now and keep cost to a minimum. Is it really that bad to use OSB for this kind of application? Anything is better than the gypsum board I guess at this point.

I have a siding/roofing nailer but only have 1 1/2" nails, the james hardie install guide says 1-1/4" but does that really matter? 

http://www.jameshardie.com/d2w/installation/hardieplank-hz5-us-en.pdf


Thanks


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## mako1 (Jan 7, 2014)

It may have to do with the proximity you are to your neighbors.Can't imagine that in a country club area.
Built some places back in the late 80's-early nineties which required 2 layers of gyprock on the outside when distances between properties were less than so many feet.This was for fire walls of buildings built within 10' of the property line.Did not make a difference how close the other structure was.


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