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Engineering Judgement for stair channel stringer

Posted by Melissa Bergenover 1 year ago
Engineering Judgement for stair channel stringer

I received an engineering judgement however there is a statement on the EJ that I am not 100% clear what it means. See screen shot below. Is this saying that the unprotected steel member needs to be protected in order to provide the 2 hour fire rating?

EJ,stair stringer

1 Reply
Posted by Michael Vuover 1 year ago
Hilti Verified

Hello,
The presence of a bare steel member in your joint causes several challenges regarding the pass/fail criteria outlined in UL 2079, specifically including the temperature and hose stream criteria. Because of this, we have approached this EJ as follows:
-Design EJ with the bare steel member and utilize a modified ASTM E2837 as the applicable test method.
We are working to release a firestop system that captures these challenges soon to make future requests more transparent. This method is the pathway can take to provide a rating.
Please feel free to call us at 1-800-879-8000 for any additional questions.
Thank you,
Michael Vu
Fire Protection Engineering Team
Hilti North America
 
3701 W. Royal Lane, Suite 100 I Irving, TX, 75063
P 1-800-879-8000
usfirestopeng@hilti.com
www.us.hilti.com/firestop