The process of sheathing the tiny home was conducted with material optimization and ease of construction as top priorities, using full OSB sheets where possible and minimizing cuts on all other sheets. We used 48"x96"x.4375" OSB sheets and secured them with 1.25" drywall screws.
The exterior sheathing brought an impressive level of lateral stability to the tiny home structure; the tiny home now has no sway or deflection, as it did before the sheathing was applied.
Panels on the walls were staggered and oriented horizontally in order to 'bind' 4' framing modules together, giving added stability to the wall framing. The same principle was applied to the roof, with panels staggered and oriented in the long direction of the roof to 'bind' framing modules together; however, we used .5" thick panels as we rafters were 24" on-center. This logic breaks occasionally, such as at the South wall, where the panels around the window were sized to line up with the clear opening, using the largest panel sizes possible and avoiding complicated cuts.
At the perimeter of each sheet, screws were applied on 8" centers, while screws were applied on 12" centers in the middle of the sheet where vertical studs were located.
Smooth face of OSB oriented to the exterior face was a mistake but not a fatal one. The other side of the OSB is rough and has vertical and horizontal lines for nailing and screwing lines (we now know that).
The exterior sheathing for the walls and roof was applied in a single day with three people. The use of ladders and scaffolding were essential to the safe and clean installation of the wall panels, while a forklift was very useful in getting OSB sheets safely onto the roof.
The installation of the sheathing gave us the first sense of interior enclosure within the tiny home. The space was surprisingly much as we had imagined it, and the amount of light permitted by the window and door openings seemed highly conducive to the sense of openness and natural lighting we had intended.
For the roof sheathing, we used sheathing clips. They helped in aligning the panels in both direction and maintain consistent expansion gaps. In hindsight, using clips on the walls would be a highly recommend process. The clips also help secure on panel to another for added wind assisted panel tear.