Truss Cert Docs Not Available, Architect Gone, Contractor Gone...

[Apexpredetor]

Good Morning,

I am analyzing a roof structure for the installation of solar panels (4-5psf Load) but the building is comprised of different types of Metal plate connected wood trusses (Scissor, attic, and fink).

The contractor seems to be defunct, architect is dead, and coded dept has no truss cert.

Building was built in Mid 1990's, using M-20 plates. I believe that these are Mitek plates?

Any ideas how to analyze these plates easily without having manufacturer software?

Thanks

 

[msquared48]

Watch it. This is around the time we got over-rated limber from Canada. I've got a doc on this somewhere and may have posted it in the forum in the past.

Mike McCann
MMC Engineering

 

[Apexpredetor]

It was built in 1993 (or 1994).

I'm kinda stumped on how to approach this one. I mean, the panels only way about 4psf, but I at this point I can't justify the added stress at all without the truss cert.

I'll look for that overrated wood info you speak of.

thanks

 

[msquared48]

If you are in a snow load area, if the load has reduced since 1994 or so (not likely I agree), then you may be able to use the difference to justify the solar panels regardless of the connectors...

Mike McCann
MMC Engineering

 

[Apexpredetor]

Yes I'm in Upstate NY (CENTRAL) with a snow load of 60psf (ground).

Good Idea. I'm going to look into that a bit.

I still would love to be abel to analyze these truss plates.

Thanks again

 

[Apexpredetor]

Oh, one quick question. I wasn't around (still in Junior High) when this building was built. Any ideas where I might be able to find some of the historical snow load codes?

Thanks

 

[boo1]

try:

http://www.ecodes.biz/ecodes_support/updates/Legacy/ICBO/UBC/ICBO_UBC_main.html

 

[StrucPatholgst]

It can be costly, but one end-game outcome might be to re-model the truss, and size new gussets, either metal or structural plywood. I can't see how you'd model factory applied plates and glue, without a) a factory cert or b) assuming the risk.

 

[jdgengineer]

Some building departments are receptive to discounting the live load (possibly even to 0) where the solar panels are installed as it's unlikely you'll have the full roof live load at the solar panel locations. I don't typically do this, but is one possible approach.

 

[Triangled]

Jdgengineer maybe I'm misunderstanding, but....
I can see some logic in live load reduction where no snow loads occur, but cannot understand reasoning where snow occurs. Could you please elaborate?