1997 UBC/IBC Exterior siding Question?

[Terry Sandmeier]

In these codes at this time was there a requirement for moisture-resistant protection of structural sheathing (OSB and plywood). I know 2006 IRC did expand on this requirement but I am doing some back tracking for a house that was built in previous code requirements. I do not have the resources at hand to check. I inspected a house that did not have a moisture barrier under ruff hewn wood lap and some sheathing is visible. Any insight would be appreciated.

[Fred Weck]

The 1997 UBC Section 1402 (IBC didn't exist until 2000) required a weather resistive barrier with the same basic language as the 2006 IRC but with 6 exceptions as opposed to the IRC's 3 exceptions. Exception 4 allowed it to be ommitted "Over water-repellant panel sheathing", which is probably what you are seeing.

The 2000 IRC Table 703.4 would have also allowed the wood siding to be installed with out the weather resistive barrier.

[Terry Sandmeier]

Thanks Fred, the sheathing was OSB and the county were this house was built does not need an building inspection for exterior sheathig is it is completed with OSB or plywood. I was looking for more info.