So what's with the random bits of plywood?

This is probably an obvious for people in the know, but I'll ask anyway. My frame has just been finished and I noticed there are a few bits of plywood around the place. I've seen this on other houses so I guess it's normal. It's obviously not load bearing so I can only guess that it's for bracing. But then there's strips of steel everywhere for that, so I'm baffled.

here's some pictures so you know what I mean:

bracing

The ply provides initial bracing to keep the frame square during assembly. The steel straps provide additional bracing once everything is erected.

more specifically plywood is used for wind bracing

Cool. Thanks folks.

I asked my SS the same thing - when they don't have enough room to angle the bracing framework or require extra strength for certain areas they use the plywood.

http://oak.arch.utas.edu.au/tbia/view_a ... icleID=127

“Buildings are vulnerable to wind damage at all stages of their life cycle. They are particularly vulnerable during the construction phase, especially if roofed with terra cotta or concrete tiles prior to the installation of wall linings or cladding, which is common practice. The installation of plywood bracing, prior to roofing, protects the building during this vulnerable period. It also protects the finished structure from damage from wind during its design lifetime of over 50 years.

Plywood bracing provides an engineered solution using thin structural plywood panels nailed to the timber frame, providing structural shear walls which resist the horizontal racking loads applied to the building by the wind. The plywood panels can be used also to provide resistance to wind uplift by connecting the roof to the subfloor.”

source:http://oak.arch.utas.edu.au/tbia/view_article.asp?articleID=52