On Oct 13, 1:01*pm, dpb wrote:
DD_BobK wrote:

...

also....Metal roofing is not all that lightweight *20 gage steel would
be ~equal to 7/16 OSB.

You'd be hard pressed to find 20 ga exterior siding; 26 is far more
common inexpensive. *Didn't look up actual mil thickness difference but
it's certainly quite a lot lighter.

That said, the question of what the lower chords are designed to carry
still remains and will until OP finds out unless he does just want to
wing it and see what happens...(not highly recommended, btw ).

--

Thanks Duane...

I just pulled the a number out of the air to do the weight calc.....

20 gage (.038?) was the only "thin" gage I could recall.

I have no experience with metal siding & only minimal with metal
roofing.....I thought 20 gage was pretty thin

but it looks like roofing and siding are even thinner than I had
imagined.
Plus (doh!) I was thinking steel....aluminum would be even lighter

So maybe a ceiling made of siding makes sense?

cheers
Bob