Here is a common question posed by one of our clients and answered by Phil Brooks:
Question: The siding contractor was worried that the clapboards would not hold well into the OSB of the sips. Over time he says that the clappords will shift if they are not nailed into studs.
I'm glad to hear that he is concerned because it shows me that he is conscientious. My experience with the thirty year old panels on our kitchen addition is that they hold nails as well or better than on the main body of the house which has studs and 1" boards. I replaced some cracked clapboards on the kitchen panels last year and only about 1 in ten nails did not have the head pull through the clapboard. The were a few loose nails, but actually less than on the main body. We also have several 20 plus year panels sided with shiplap boards which are much heavier and expand and contract more than clapboards.
The exterior sheathing is not standard OSB. It is rated as "SIP grade" which has been specifically engineered for this application with more resin for nail holding ability. If you use stainless ring nails you should not have a problem, especially if you follow our spes and use 30# felt and homeslicker under your siding and trim boards.