Fire Rating System

[Veer007]

Hey Guys, Why generally floor steel to be fireproofed (especially under composite deck or core slab) and Roof steel not? What are the statics behind that? Do anyone assist me!!

Thanks in advance!!

 

[RPMG]

There's no one on the roof.

 

[KootK]

I've wondered about this myself. Some thoughts:

_ you're not on the roof but the roof could fall on you.

- a fire in an occupied space under a roof that might cause that roof's collapse would quickly clear out the occupants of that space.

- a fire over a roof that might cause that roof's collapse is often prevented through the use of non-combustible roofing assemblies.

- some judgement is warranted. I've fireproofed roof's under mechanical penthouses in the past.

-

 

[RPMG]

Smoke kills people, not the fires themselves. The fire rated floors prevent people above from asphyxiation. The people below are already toast.

 

[KootK]

The fire rated floors prevent people above from asphyxiation.

But they do that by retaining their structural integrity long enough for folks to escape the space. It's not the case that a fire rated floor is just an intact smoke enclosure. Egress is the name of the game for the most part.

 

[r13]

Veer07,

Where you find the clause that states roof steel does not require fire proof?

 

[r13]

See IBC2015 Table 601 for fire rating requirements for building elements. Also, Section 704.3 for fire proof of structural members.

 

[JLNJ]

One of the reasons you might not need to fire rate the roof structure is related to roof height. If the roof is significantly above the floor, say at least 25', the IBC says you can reduce or eliminate the roof rating. It all depends on the height, area, use, fire suppression method, construction type, etc.

 

[Veer007]

Where you find the clause that states roof steel does not require fireproof?

I have seen this case on many contract dwgs typ...

thanks for the guidance....

Thanks in advance!!

 

[Veer007]

So, still, can we fireproof roof steel? if required...

Thanks in advance!!

 

[r13]

I think the fireproof of roof steel has no difference with other steel members.

For those project without fireproof the roof steel, you should check into other possibilities than waived the requirement, such as fire rated ceiling, sprinkler ...

 

[Veer007]

yes.. retired13, i agree... for the columns, I do paint them as I have fire-rated stud wall assembly which covers all columns, so the beam only to be fireproofed.

Thanks in advance!!

 

[RPMG]

Yes, there are fire-rated or fire-resistant roofs, and I believe that some roofs are required to be fire-resistant. Sometimes, fire-resistance is added to the outside, assuming the fire will originate from the exterior.