For new projects OSB is used almost exclusivly. If I spec plywood, I am
chastised by the contractors for wasting the owners money since OSB is easier
to obtain and signifficantly cheaper. Inasmuch as our climate is dry and hot,
OSB does not have the problems that is assoicated with the coastal areas
where if left to exposure will cause it to discolor and deteriorate much
Therefore, I am forced to comply with the code allowable for OSB and allow
the contractors to use it whenever they want.
I allow it also for reroofing. Here it is not so big an issue since the
perfered method is to apply it over the 1x space sheathing. Again, I am
chastised if I suggest removing the skipsheathing and apply the OSB or
I try to warn the owners that this method creates a problem in the
possiblilty of nail bending and unnecessary weight. The homeowner or HOA
representative is more concerned about cost than the potential damage and
will almost always take the contractors experience over the more complicated
choices I would suggest.
Where existing sheathing is retained, I find that it is almost always
Plywood. Obviously due to the age and newness of OSB.
Sorry if this seems evasive, but in most cases my hands are tied by cost and
I make it very clear in the report that I have discussed the options in depth
with the owner or owners representative and list the decision they have
chosen. I also require the owner or owners rep and the contractor to initial
the report prior to submittal to the building official so that they
acknowledge that they have read and understand the report.