Robertson Q Deck

[Jerehmy]

I've seen other threads about the deck, but I can't seem to find the one specified on these old plans.

Here's a direct quote from the drawings "1-1/2" Steel Roof Deck. -Robertson
"Q"-Deck No. 3"

The drawings are from 1950. The deck is for a roof. It does not have concrete just insulation and built-up roofing. I'll be looking at in person today, just hoping I might get some catalog information.

Thanks!

 

[JAE]

Have you tried slideruleera's site:

http://www.slideruleera.net

Check out Eng-Tips Forum's Policies here:
faq731-376

 

[msquared48]

See if you can get ahold of ICBO Report #1388 from November of 1980. Robertson Steel Floor and Steel Roof Deck.

There might be some information there you can use as they do mention 1.5" deck, but mostly 2" and deeper steel sections.



Mike McCann, PE, SE (WA)

 

[Jerehmy]

Looks to be identical to Robertson 18 gauge "section 3" deck, although that catalog is from 1980 and the plans are from 1950. That should suffice, I'll just have to find a good allowable stress. The 1968 robertson catalog used 20,000 psi. Would they have used similar values in 1950?

I couldn't find that ICBO report.

 

[msquared48]

I have no idea re4garding the steel stress, but the further you go back, the more likely A7 was used. So, 18,000 would be conservative...

Mike McCann, PE, SE (WA)

 

[SlideRuleEra]

Allowable bending stress in 1950... 13.5 KSI to 18 KSI, depending on the grade of ASTM A245 or A246 steel used for the decking.

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[msquared48]

OK. So I guess that 13.5 would be conservative...

Mike McCann, PE, SE (WA)