Originally Posted by
Robert Alexander
Good point and great picture! I have actually instructed my contractor to keep the skip sheathing in place for support and install the 7/16 OSB on top of it like your picture illustrates.
Robert,
Here is why that is not the best idea (the best idea is to take the spaced sheathing off and install the OSB/plywood directly on the rafters):
- The OSB or plywood would not be supported entirely along their ends, unless ... you went to the trouble to cut strips of the same thickness as the spaced sheathing and securely nailed those strips to the top of the rafters.
- The nails used would have to be enough longer to compensate for the extra 3/4" or more of wood thickness of the spaced sheathing.
- Even with the above being done, the structural panel sheathing will lose some of the load it is transferring to the structure (the rafters) with the nails through the spacers between the spaced sheathing and through the spaced sheathing (the sheathing now would have an indirect connection to the rafters).