Every site's different so we recommend your engineer designs your frame. It's the specifier's/user's responsibility to make sure the hoarding and supporting framework meets structural requirements.
Here are a few tips:
- Seal or topcoat your edges and fixing holes that are treated with putty.
- To protect from the elements, leave some expansion gaps to allow for stretching; 3mm gaps between panels are standard.
- If the fence abuts a rigid upstand or a wall, leave 10mm.
- OSB will give you a good paint finish and using the appropriate finish will make your panels last longer.