how to fire proof steel beam with wood nailer on top

[johndeng]

as title, we can fire proof steel beam, but what about wood nailer? there is no slab, floor joists frame to steel beam nailer with hanger.
also do we have to PAF wood nailer to steel beam?

Thanks

 

[msquared48]

Two layers of 5/8" sheetrock on the underside of the joists that also are over the nailer...

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[johndeng]

Thanks Mr. m^2
you are talking sheetrock rock betweem joists and nailer? so we can't use hanger, it will has to be bear on nailer. will that crush sheetrock?
also do we have to PAF wood nailer to steel beam? we do, but I dont know why.

 

[msquared48]

With a hanger off the nailer, the joists would hang below the nailer. With the sheetrock nailed below, if you extend the sheetrock to the steel beam and provide an attachment surface at the steel beam web for the sheetrock, assuming that the joists do not hang below the steel beam, the nailer would be protected how I see things. The sheetrock would not be between anything and would see no crushing loads.

Is there another problem that I am not seeing?

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[johndeng]

Thank you Mike.
So if with hanger, extend sheetrock to beam web, and fire spray beam.
if bear on top, still extend sheetrock and drop down to beam web surface, then fire spray beam. am i right?

 

[BAretired]

Provide a cross section. Then we will all know what you are talking about.

BA

 

[johndeng]

great BA showed up again.
here is the sketch for both dropped beam and flush beam with hanger.

 

[johndeng]

here again

 

[msquared48]

OK. You have the flush beam condition then. As I said, put the required layers of sheetrock on the underside of the joists to get the fire rating you need. Install a wood nailer on the bottom of the steel member, and wrap the same sheetrock around the steel beam below the joists and firetape the seams.

Apparently, the hangers are not only top hung, but also side hailed into a wood ledger fit between the flanges of the steel beam - not uncommon.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com