Does a Giant steel beam in garage need sheetrock?

[Coder]

I have a garage that has a giant reclaimed steel beam from a bridge that is being used as support for the living space/floor joists above. With the garage to living separation requirements in mind, do I make the owner wrap the beam in sheetrock even though they want to leave it exposed for aesthetic purposes?

 

[mtlogcabin]

By giant do you mean the height and width or do you mean the thickness of the steel.

A thicker steel beam would have a longer exposure time before failure than a thinner beam of the same size

In reality the beam should be wrapped to give the same 30 minute protection to all structural members before being exposed to the fire and heat.

 

[Rider Rick]

Great question.

If it was a soild wood beam I would say no sheetrock required.

But steel I would say get engineering or cover the beam with sheetrock.

 

[globe trekker]

Mr. Inspector,

From Section R309.2 in the 2006 IRC: Separation required.

The garage shall be separated from the residence and its attic area by not less

than ½-inch (12.7 mm) gypsum board applied to the garage side. Garages beneath

habitable rooms shall be separated from all habitable rooms above by not less than

5/8-inch (15.9 mm) Type X gypsum board or equivalent. Where the separation is a

floor-ceiling assembly, the structure supporting the separation shall also be

protected by not less than 1/2-inch (12.7 mm) gypsum board or equivalent.

Garages located less than 3 feet (914 mm) from a dwelling unit on the same lot

shall be protected with not less than ½-inch (12.7 mm) gypsum board applied to

the interior side of exterior walls that are within this area. Openings in these walls

shall be regulated by Section R309.1. This provision does not apply to garage

walls that are perpendicular to the adjacent dwelling unit wall.

Since your steel beam is part of the floor-ceiling assembly, IMO, the BO could

approve it without the gypsum board applied to it, as long as, all areas are sealed

completely and or draft-stopped.

.

 

[Coder]

Thanks for the replies. Helps a bunch. The I beam is approx 3/4" thick steel. Only issue in 30 minutes of burn time is going to be everything else around it burning down . IMO. I am going with the or equivalent approach on this one.

 

[steveray]

In the IRC...it needs drywall.....IBC maybe some engineering analysis or intumescent paint?

 

[Sifu]

On a related note.......Don't remember where it was but in the last few days I read a test report comparing the structural integrity of a steel beam to a solid wood beam. I was amazed. After 30 minutes the wood beam still had 75% of its original size and suffered 1 1/2" of deflection while the steel beam deflected 30" and failed. Both beams were normally loaded and exposed to a typical residential fire test in a furnace.

 

[steveray]

Town near here had ALOT of old mill fires back in the 70's and 80's.....large wooden beams last way longer....in their installed position....the steel will be there longer, but it will be a pretzel in the basement!

On a related note.......Don't remember where it was but in the last few days I read a test report comparing the structural integrity of a steel beam to a solid wood beam. I was amazed. After 30 minutes the wood beam still had 75% of its original size and suffered 1 1/2" of deflection while the steel beam deflected 30" and failed. Both beams were normally loaded and exposed to a typical residential fire test in a furnace.

 

[globe trekker]

In a fire rated event, the intent is not to save the structure, but rather for emergency

rescue of any live occupants.

It is true that "true" heavy timber wooden beams last longer in a fire event. I seem

to recall something about heat transference throughout the beam itself. Wood won't

transfer the heat whereas, metal types will, thus weakening the overall strength of

the beam.

Also, agree with "Rider Rick" above, ..this is a great question! Or put another way,

what would you do in your own personal home if you wanted to install one of these?

.

 

[Inspector 102]

If I remember correctly, steel starts to break down structurally at about 1100 F and failure soon follows. Trust me, temperatures can reach that in a normal residential fire at ceioling levels. I am in agreement that the steel should be wrapped with sheetrock for protection. Not what I would want coming down on my head during an interior fire attack.

 

[Coder]

Just a thought, what if the builder were to install the 5/8" sheetrock on the top side of the beam prior to framing the ceiling. Not sure how it would all plane out but could that be a viable solution?

 

[Darren Emery]

That steel beam must be protected. 1/2" gyp board, or the equivalent.

 

[Darren Emery]

Just a thought, what if the builder were to install the 5/8" sheetrock on the top side of the beam prior to framing the ceiling. Not sure how it would all plane out but could that be a viable solution?

That still leaves the beam exposed.

 

[ICE]

5/8 type X

 

[High Desert]

You can basically have an unlimited number of 26 gauge ducts penetrate the minimal garage/dwelling separation. How long does that last in a fire. I wouldn't be concerned about a 3/4 inch thick steel beam.

 

[Darren Emery]

High Desert - I agree, the beam will last longer than the duct. However, the code does not state the the duct must be protected. It does say that the beam must be protected.

Ice - I get ya, the floor ceiling requires 5/8x, the supporting structure requires 1/2. Do we call the beam part of the assembly, or a supporting structure? Either way, it should be protected.

 

[MtnArch]

What about using Intumescent paint, like this (Firetex M90 - Protective & Marine) from Sherwin-Williams?

 

[mark handler]

What about using Intumescent paint, like this (Firetex M90 - Protective & Marine) from Sherwin-Williams?

That is protection

 

[globe trekker]

..or equivalent!

.

 

[fatboy]

We require beams in this application to be wrapped, period. To be fair, I would look at coatings.......

 

[mark handler]

painting, less likely to be removed, after the final......

 

[Coder]

What about using Intumescent paint, like this (Firetex M90 - Protective & Marine) from Sherwin-Williams?

I believe that is only to protect from ignition and not from thermal conductivity. The beam is still going to get hot with an intumescent paint and possibly hot enough to deform and create a collapse scenario which is what the sheetrock wrap would help prevent. Still think it is silly to wrap a 3/4" thick 12" x 16" steel beam reclaimed from an old railroad bridge in drywall. If it were me, I would not bother to use the beam structurally, knowing that it would have to be covered. Re-design with floor joists that could span without it, sheetrock as required, and move on. Then if I absolutely had to have the old railroad bridge I-beam in my garage, I'd put the beam up as a stand alone item for aesthetics (after the final inspection ) Did I just say that? :cheers

 

[ICE]

We require beams in this application to be wrapped, period. To be fair, I would look at coatings.......

I would look at the coating too.....and then ask them to call me when they get it rocked.

 

[mtlogcabin]

I believe that is only to protect from ignition and not from thermal conductivity. The beam is still going to get hot with an intumescent paint and possibly hot enough to deform and create a collapse scenario which is what the sheetrock wrap would help prevent. :cheers

intumescent paint does provide a thermal barrier. That is how it works. When steel looses 60% of its yeild strength it is considered a structural failure. That can happen at a low tempeture than wood.

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