de-sheath i-beam in attached garage? Code?

[goofygrin]

I'm trying to figure out if I can get a 4 post lift into my 3 car tandem garage and every inch is going to count.

About 5' from the front of the garage, we have a beam that's sheetrocked in. Due to it's dimensions (~23" tall, 8" wide) I got curious and jammed a screwdriver in and heard a metal clang. Metal I-beam like we have in the basement holding up the front of the second story.

A neighbor pulled some of the sheetrock off a beam in their garage and this is what they found (picture). This was in a different part of the garage with a lower beam (smaller i-beam).

If I were to pull the sheetrock and framing (2x4s) off that would get me another 2" which would help with car clearance on the lift. But... would that be against code as I think sheetrock in the garage is required for fire break? Could I fill in the gap between the i-beam to the rest of the sheetrocked roof with spray foam or something to keep that firebreak there?

 

[readhead]

The beam is required to be protected from fire by code. Drywall is the easiest and most common treatment. Spray foam is not rated for fire. A product called monocoat is used in commercial applications but it would be very expensive for a small application.

 

[strutaeng]

Is that 1/2" or 5/8" drywall? You could probably ask your local jurisdiction if there's any fire code requirements?

 

[CraigStu]

I think you can figure out a way to get rid of the 2x4s(?) on the bottom of the beam. If there were just drywall there you would gain 1.5". Maybe one of the instant grab construction adhesives.

 

[mike93lx]

No idea what code requires, but practically, if the fire is bad enough to damage the beam, I can't imagine that a piece of drywall is going to make a lick of difference.

 

[Fixr]

No idea what code requires, but practically, if the fire is bad enough to damage the beam, I can't imagine that a piece of drywall is going to make a lick of difference.

From what I've read, steel becomes weakened surprisingly fast in a fire (wood beams of the same load capacity hold up way better), and drywall is surprisingly effective at resisting fire.

 

[larry4406]

5/8 Type X drywall gets you about 1 hour rating.

This means it gives you more time to get out or begin fire suppression while holding off the flame spread for about 1 hour.

I would not leave the beam exposed.

 

[mike93lx]

From what I've read, steel becomes weakened surprisingly fast in a fire (wood beams of the same load capacity hold up way better), and drywall is surprisingly effective at resisting fire.

Maybe I'm way off on my assumption. Would love any data on this.

I have a few steel beams in my current house, but all are wrapped in drywall. My folks have an exposed steel beam in a house we are renovating, so if there is a strong case for wrapping it, I'll make sure it gets done

 

[txvwnut]

Move the lower 2x4 to the inside of the web with enough stick out on each side of the beam to attach the lower piece of sheetrock to. You'll gain the distance in height of the moved the 2by and still be able to finish it out for any code compliance.

 

[Fixr]

Maybe I'm way off on my assumption. Would love any data on this.

I have a few steel beams in my current house, but all are wrapped in drywall. My folks have an exposed steel beam in a house we are renovating, so if there is a strong case for wrapping it, I'll make sure it gets done

It's been decades since I read about it, but the gist was that a heavy timber beam will char on the outside from a fire, and the char helps insulate the interior of the beam from the flames, while steel transfers the heat throughout the beam, and it sags and twists. There were photos of burned industrial buildings with wooden beams and steel beams. The wooden beams were largely intact and supporting loads, while the steel beams were drooping and twisted. I've run into a few references about it since, but have never done any in-depth research.

 

[mike93lx]

It's been decades since I read about it, but the gist was that a heavy timber beam will char on the outside from a fire, and the char helps insulate the interior of the beam from the flames, while steel transfers the heat throughout the beam, and it sags and twists. There were photos of burned industrial buildings with wooden beams and steel beams. The wooden beams were largely intact and supporting loads, while the steel beams were drooping and twisted. I've run into a few references about it since, but have never done any in-depth research.

I was thinking more about rhe wood framing and a steel beam, not necessarily the comparison between wood and steel for beams. If it's hot enough for a steel beam to have a problem, what's happening to sawn joists, or even worse, I joists?

 

[Fixr]

I was thinking more about rhe wood framing and a steel beam, not necessarily the comparison between wood and steel for beams. If it's hot enough for a steel beam to have a problem, what's happening to sawn joists, or even worse, I joists?

I think that's why they want them all wrapped in drywall for firewalls, but I'm no expert.

 

[rlitman]

5/8 Type X drywall gets you about 1 hour rating.

A wall system constructed with 5/8" type X on both sides gets you a 1 hour rating. This single layer isn't rated for an hour of protecting that beam, but regardless, it's still necessary.

However, the way this is skinned leaves room for improvement. There's no structural reason for a 2x to be attached to the underside of the steel. It makes attaching the drywall easier, and leaves something solid to hang stuff from, but technically you could delete that and get back 1-1/2" overhead. You'd just have to figure out how to widen the beam with wood, so you could screw your new drywall sheet in at the sides.

 

[billconner]

Is this a single or two family dwelling? That will make a big code difference.

I think the suggestion to reframe with just 5/8 drywall under is most pragmatic approach, but removing and painting with intumescent coating is interesting. On projects I've worked on, intumescent paint is referred to as liquid gold by the contractors. It's not to my knowledge explicitly allowed by the IRC but I'd think a discussion with the building department would allow it. And don't get fooled by fire retardant paints - this is pretty special, the way it foams up and creates a protective layer.

 

[goofygrin]

Single family, two story + basement. This beam supports the load on the front of the house. I am not sure if the beam runs across the living space in the front of the house (there's no corresponding "beam" in the room next to the garage).

 

[driftpin]

At an in-service seminar on 9/11, for fire inspectors, I heard a presentation about the construction methods used when the TTT was built in the 1970's. It opened 4/4/1973.

There were multiple methods used for providing fire resistance. When the fueled plane impacted the building, the shock wave knocked-loose the steel coatings and drywall, and the ruptured fuels spilled throughout the structure down from the point of impact. The damage to the building destroyed the sprinkler systems, rendering them inoperable. Once the fire spread, the supporting structure weakened and a pancake collapse as we all saw, to our horror, took out the inhabitants and 343 firefighters from FDNY.

One of the issues in construction is that the trades are responsible for restoring the fire-resistive buildings' methods of construction. They may not do that, effectively, and in the absence of vigilant enforcement by the lifesafety inspectors, and the other trades inspectors the building is susceptible to structural failure in the event of a fire.

Francis Brannigan SFPE (the USA has more licensed psychiatrists than fire protection engineers) and Vincent Dunn Deputy Chief FDNY (ret.) have continuously advocated for better fire protection standards and methods of fire-resistant building construction. One of the statistics relevant to potential weakening of a steel structural member is that a 100ft. beam lengthens 9-1/2 inches as it reaches 1,000 degrees F. What happens to the structural integrity of a building under such conditions? If the concrete structure containing steel beams is massive-enough to prevent that amount of expansion of the steel structural member, that will cause the middle of the steel beam to buckle/fail.

Construction Concerns: Expansion of Metals

The expansion of steel beams under fire conditions can cause structural collapse. Gregory Havel reviews devices used to control the expansion of pipes and the effects of expanding structural steel.

www.fireengineering.com

When I entered the fire service nearly 50 years ago, we were taught that steel bar truss construction was capable of withstanding collapse for nearly 10 minutes, but the accumulation of evidence since then has shown that collapse of the structural element can happen in in two minutes or less, given the proper conditions. Data-driven information helps us to understand the changes in the building involved in a structure fire, and to understand how buildings can be made more fire-resistant with advances in building construction and new materials. Occupants are given a better chance of evacuation from an involved building, and firefighters a better chance to protect lives, reducing morbidity and mortality, and hopefully being able to stop the spread of fire, and to extinguish the conflagration while stopping the spread to other occupancies.

Here is a synopsis of issues raised in a forensic review of the TTT disaster.

https://jnocook.net/texts/wtcfire.htm

I am a retired firefighter/paramedic, lifesafety inspector, and FL licensed fire service instructor III, and hold other qualifications.

 

[dutchgray]

Is this a single or two family dwelling? That will make a big code difference.

I think the suggestion to reframe with just 5/8 drywall under is most pragmatic approach, but removing and painting with intumescent coating is interesting. On projects I've worked on, intumescent paint is referred to as liquid gold by the contractors. It's not to my knowledge explicitly allowed by the IRC but I'd think a discussion with the building department would allow it. And don't get fooled by fire retardant paints - this is pretty special, the way it foams up and creates a protective layer.

I have worked on a commercial warehouse/ office building in which Intumescent paint was used to protect the structural steel work of the office part (the stanchions, roof portals, floor columns and beams were all painted), a specialist contractor had to do the work for it to be accepted (with some type of pressure sprayer system) and a thick layer of the paint was sprayed on, it was relatively expensive, but less expensive than trying to box in all that steel.
I'm in the UK so our actual requirements will differ.

 

[dcg9381]

From what I've read, steel becomes weakened surprisingly fast in a fire (wood beams of the same load capacity hold up way better), and drywall is surprisingly effective at resisting fire.

I'm surprised at a requirement to wrap a (steel) beam also. Wrapping a "beam" (which would be assumed to wood) makes total sense to me though.

I have a steel post in the garage, why not require that to be wrapped?

By the time a fire is hot enough to weaken it to the point of deflection, I think you're pretty well screwed...

 

[rlitman]

...I have a steel post in the garage, why not require that to be wrapped?...

Lally columns are steel tubes filled with concrete. Even if the steel is softened by the heat of a fire, it should only lose a fraction of its compressive strength (of which it has way overkill to begin with). Contrast that with an I beam that when heated hardly has enough strength to hold itself up, not to mention it's intended load. There's a big difference.

 

[lmg]

I see that above dutchgray mentioned intumescent coating. I have worked around it some. Locally, it is usually applied by insulation contractors. It goes on thick, so 5 gallons may not be too much for your application.

Here is a link to just the first product that showed up when I searched:

https://flameoffcoatings.com/intumescent-fire-resistant-paint?utm_source=Adwords&utm_medium=cpc&utm_campaign=NewMexico&utm_term=fireproof%20coating&gad_source=1&gclid=EAIaIQobChMItfHr9uOShgMVaAOtBh389QPjEAAYASAAEgLXK_D_BwE

These products are expensive, but it may be worth it for your situation.

 

[MovingAlong]

... would that be against code as I think ...

There is only one source for determining your local codes - the AHJ (Authority Having Jurisdiction). That's the person you want to talk with.

Have always had great luck with simply calling and stating, "Hey, I'm looking to do ____ right. Can you help me with the process and relevant local codes?." Or something like that...

 

[MovingAlong]

Kind of a famous pic showing steel beams bent over wood from a fire:

 

[mike93lx]

Kind of a famous pic showing steel beams bent over wood from a fire:

But at that point, does it matter? It's not like that wood beam is usable anyway and I don't really care if the beam is bent when the rest of the house has collapsed around it.

 

[MovingAlong]

But at that point, does it matter? It's not like that wood beam is usable anyway and I don't really care if the beam is bent when the rest of the house has collapsed around it.

I'd think so. That wood beam is still keeping the steel from landing on someone's head.

But I'm not a structural engineer and have no burden either way. Just enjoy seeing that some of the "old ways" still have value. Especially as I become one of the "old ways" that things used to get done!

 

[mike93lx]

I'd think so. That wood beam is still keeping the steel from landing on someone's head.

I swear, I'm not just stirring the pot.

If someone was under that beam, the fire would have taken them out before the beam bent.

I am not arguing that wood can have benefits over steel. But do they really matter in a house fire?

Just trying to learn and see other perspectives

 

[MovingAlong]

If someone was under that beam, the fire would have taken them out before the beam bent.

I'll concede that point.

 

[Walkers]

If you are that close to fitting a 2 post lift I would say find a better place, or plan for a different kind of lift.

 

[duneslider]

Unless someone can pull up the residential code reference I am calling BS on having to wrap metal. I have exposed steel beams in my house. I am currently sitting in my office at work and can see exposed structural steel everywhere around me. I am on commercial job sites all the time with exposed structural steel. I did work in a building that had some flammable material storage and they did require all the structural steel in the storage areas to be fire coated.

A garage does require fire barrier to the rest of the house, so if you did remove the drywall on the beam any gaps would have to be properly dealt with. The ceiling in a garage with living space above requires 5/8" drywall.

Fire code isn't to protect the structure, it is only to give people enough time to escape and not die. The steel will hold up much longer than the TJI floor will.

 

[duneslider]

Okay, I have spent some more time thinking. Commerical places usually have fire sprinklers which would keep the metal cooler. I looked around the code book and I still can't seem to find anything saying steel beams need to be covered.

I have heard that in some places there are local codes that require the undersides of TJI's be fire protected even if the basement isn't finished. Generally, the easiest way to do this is drywall. This isn't in the code book (yet) but could see it coming someday.

Again, I still can't find anything saying the beam has to be covered.

I have structural I-beam and C-channel exposed in and out of my house and there were no issues with code compliance.

 

[dcg9381]

If someone was under that beam, the fire would have taken them out before the beam bent.

I did some digging and there is deflection of steel (both heating and cooling) in "reasonable" temperature ranges.

But deformation of steel, we are talking well over 200 degrees F at 50-70% load. That's well into "the place is screwed" temperatures.

The photo shows a bent beam. Lateral load, not the load that beam is designed for... We all know if you heat steel long enough you can bend it, but nothing I'm aware of says that this can happen at temperatures that aren't extreme enough to destroy the rest of the structure.

 

[readhead]

Exposed steel is very common in residential and commercial construction. What tips the scale here and similar situations is it is part of the fire separation assembly between the garage and the living space.

 

[readhead]

A good example is a house I’m working on right now that is full of exposed steel and the garage has exposed steel beams also. The difference in this situation from the OP’s is that the separation between the garage and living space is simply the wall and doesn’t include any living space above the garage.

 

[Jagmandave]

OK, so the reason it's OK for the basement to have exposed steel girders is that the garage is more likely to have a fire? Cause I have living spaces over both the garage and basement (split level home - bedrooms are over the garage) The steel beam in the garage is covered with drywall, the one in the basement is not - house built in 1964

 

[billconner]

I think the code clearly requires the steel beam and columns supporting habitable space above to be protected by drywall. See third item in chart "Structures supporting...."

I don't know if a typical small concrete filled steel column is rated. All I find in codes are ones at least 8" wide.

R302.6 Dwelling-garage fire separation.​

The garage shall be separated as required by Table R302.6. Openings in garage walls shall comply with Section R302.5. Attachment of gypsum board shall comply with Table R702.3.5. The wall separation provisions of Table R302.6 shall not apply to garage walls that are perpendicular to the adjacent dwelling unit wall.

TABLE R302.6

DWELLING-GARAGE SEPARATION

SEPARATION​	MATERIAL​
From the residence and attics​	Not less than 1/2-inch gypsum board or equivalent applied to the garage side​
From habitable rooms above the garage​	Not less than 5/8-inch Type X gypsum board or equivalent​
Structure(s) supporting floor/ceiling assemblies used for separation required by this section​	Not less than 1/2-inch gypsum board or equivalent​
Garages located less than 3 feet from a dwelling unit on the same lot​	Not less than 1/2-inch gypsum board or equivalent applied to the interior side of exterior walls that are within this area​

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.

 

[readhead]

A concrete filled column is not rated.

 

[TRWham]

OK, so the reason it's OK for the basement to have exposed steel girders is that the garage is more likely to have a fire? Cause I have living spaces over both the garage and basement (split level home - bedrooms are over the garage) The steel beam in the garage is covered with drywall, the one in the basement is not - house built in 1964

There is no required fire separation between a basement or crawlspace and the space above (except for fireblocking and/or draftstopping as needed). That does assume the framing is 2x10 or greater, which it would usually be. There is required separation between a garage and the space above, 1/2" DW for attic and 5/8" Type X for habitable space, so the supporting structure must be covered, as billconner posted above. There is no exception for steel.

 

[racecougar]

At an in-service seminar on 9/11, for fire inspectors, I heard a presentation about the construction methods used when the TTT was built in the 1970's. It opened 4/4/1973.

There were multiple methods used for providing fire resistance. When the fueled plane impacted the building, the shock wave knocked-loose the steel coatings and drywall, and the ruptured fuels spilled throughout the structure down from the point of impact. The damage to the building destroyed the sprinkler systems, rendering them inoperable. Once the fire spread, the supporting structure weakened and a pancake collapse as we all saw, to our horror, took out the inhabitants and 343 firefighters from FDNY.

TTT = WTC? I Googled, but found no correlation between the two acronyms.

 

[rlitman]

TTT = WTC? I Googled, but found no correlation between the two acronyms.

Yeah, it has to be an autocorrect issue.

 

[billconner]

I've seen ttt used for twin trade towers meaning WTC but not often. Maybe a Florida fire service colloquialism. I was however drawn to the urban dictionary meaning.

 

[racecougar]

I've seen ttt used for twin trade towers meaning WTC but not often. Maybe a Florida fire service colloquialism. I was however drawn to the urban dictionary meaning.

Ah. This would be the first time I've heard that term for the WTC. Seems it isn't popular on the net, as Google didn't pick it up.