[Shop-talk] Building/adding a deck cover?

[Obaa]

I didn't see this come back, so resending...

> Thanks for the comments guys.
> 
> It sounds like there are some mixed opinions on this stuff,
> but dependent on the material?  I'm specifically
> planning on using the translucent white polycarbonate
> stuff, not the ondura roof panels.  It seems like these are
> okay?
> Is the concern with the wind-loading due to the top
> swaying?  The bottom of the posts will be anchored to the
> deck.  I had hoped to leave the top unattached due to the
> permitting issue.  (I'm also reluctant to cut through
> the siding since we have the "bad" LP chipboard
> siding.  I know I need to replace it, but it's been
> holding up so far, and we were planning on getting the
> addition done at the same time as the residing.)  I thought
> if I triangulated the support posts at the top, that would
> be sufficient to keep the top from swaying; maybe a few lag
> bolts into the house would help?
> Is there more loading on an open structure like this than a
> fully enclosed building?  I would think the wind could just
> blow through it, while an enclosed building would have more
> of a sail area.  Or is there some lift going on that I
> haven't accounted for?  If the panels themselves are
> too flimsy, I can "box" the bottom of the trusses
> with some 1/4" plywood (I have a lot of that); then the
> loading would only come from the top.
> I'll try the google sketch-up.
> Any other ideas or comments, please let me know.
> 
> Thanks!