Fireproofing tube steel. 1

[EKizak]

I have a condition were an exterior girder abuts a stairwell. As a result I have an lu of 15ft. I would like to use a HSS section to minimize the width and keep the section in the plane of the wall studs. However, the Architect does not know of any approved UL ratings for this assembly. This does not make sense to me because the fireproofing requirements are based upon the ration of weight to heated perimeter, and a tubes ratio will significantly greater then a WF hence better fire resistance. Has anyone had this issue? How was it addressed?

Thanks

 

[dik]

CIDECT (

http://www.cidect.org)

has information on fire resistance of concrete filled columns... earliest work I'm aware of in this area were columns for a stairwell that were done about 30 years ago at the U of Winnipeg.

Other than that, I'm aware of intumescent coatings that I've used for mezzanine areas.

Dik

 

[jike]

Wrap the column in the appropriate layers of rated drywall per UL. The Architect may need to thicken the wall or install a bump out as necessary. Another alternate is to use a Dean Lally Fire-Trol column. Refer to

http://lallycolumns.com/.

 

[henri2]

Once you have determined the fire-resistance rating requirements per IBC Chapter 6 (Table 601, IBC Section 721.5.1 has procedures for achieving fire resistance compliance.

If the architect does not want to thicken the wall to incorporate a thickened fire protected column, would use of intumescent fire protection coatings work?

http://www.icc-es.org/reports/pdf_files/ICC-ES/ESR-1092.pdf

 

[EKizak]

Great answers, however the problem is not with the column. It is with the girder. Apperently UL does not list an assembly for a tube section used as a beam. UL has several listings for tube sections but only when used as column or brace members, ie P>>M.

 

[WillisV]

See this reponse from AISC:

http://www.aisc.org/MSCTemplate.cfm...tomSource/Faq/SteelInterchange.cfm&FaqID=2668

In general the column UL tests are more restrictive than a beam test would be and are therefore applicable (and conservative) to the occasional HSS beam.

 

[dik]

Thanks, WillisV: Article should include that a the cross-section for a flexural element is less highly stressed than for a column and that as temperature rises, not only does the yield strength diminish, but also the Young's modulus.

Dik

 

[EKizak]

Thank you to all.