I have a 10" thick concrete floor slab with a 40"x24" opening that we want to close off with a 1/2" steel plate fastened to the slab and we would like it to be fire rated min 1Hr.
Please advise if you have a coating system that we can use.
Hello,
I think you might be mixing up the testing standards a little bit here. To clarify, an opening in a concrete floor without penetrations would be considered a blank opening condition under the UL 1479 testing standard for through penetration firestop systems. Applying fireproofing to a steel member falls under the ASTM E119 or UL 263 testing standard, and has more to do with the load carrying capacity of the steel member under fire conditions and not restricting fire passage through the opening.
For your condition you will a system that will restore the rating of the floor assembly back to what it was before the floor was damaged to make the opening. I have attached our best reference system for this condition, but you will likely need to submit a request for an engineering judgement to have the opening size increase for your condition and wire mesh added for the larger opening size.
Thank you,
Alex Hernandez
