Adding a firewall to this metal frame 2

[stripez]

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Client needs to have firewall put since it is beside another building. The w8x21 I-beams above columns were already installed as well as 1.7mm thick vertical C-purlins spaced every 0.4 meters apart. The I-beam were to originally carry another wall on top of it but client changed his mind.

There is supposed to be double sided cement board with 9mm thick. But this doesn't have hours long fire rating.

My questions.

1. What modern materials can you use to put a firewall in it?

2. The original rebars protrusion above the concrete parapet wall and on side of each column was already cut before because owner thought there would be no roof or wall added but changed his mind. If we will use traditional masonry or hollow blocks as firewall. Can you just add rebars welded to the vertical c-purlins and I-beam above? How? Is this the only way to put masonry on it? Any ideas? Thanks.

 

[dik]

Can you use an intumescent coating?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[stripez]

I mean not just fire proofing the metal. But adding firewall. Imagine the existing cement board will be removed since it can let heat move to other side.

 

[dik]

My error... do you need 2 hrs or 4 hrs? Can you put in a sprinkler system?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[stripez]

At least 2 hours. I mostly used masonry walls (at least 4 to 6 inches) as firewall in any building or house. This is the first time I face such metal frame. Why. Do others also use metal framing like this or do you use masonry or pure concrete wall all the time?

 

[skeletron]

Might affect the stiffness of the building (whether you want it or not).

 

[stripez]

The concrete beams underneath it was designed to carry full load 6" concrete or masonry wall. The reason the cement board was used was because the protruding rebars were cut already. But it didn't have 2 hour fire rating (which was not thought of when it is built).

So how do you put masonry blocks (hollow blocks) like the following on the metal frame shown in original message?

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(this is just an example of hollow blocks)

 

[dik]

Can you use a couple of layers of 5/8" firerated GWB? or shaft wall type of construction?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[stripez]

I mostly used masonry or hollow blocks wall. I googled shalfwall and came with this.

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Which side is the existing wall. How are you supposed to use it? any illustrations you or others can share too?

 

[DBronson]

stripez:

I'm guessing from the photo you aren't in the US? In the US most jurisdictions use the International Building Code (IBC). There's a big difference between a "fire wall" and a "fire barrier". I suspect you may only need a fire barrier. Chapter 7 of the IBC covers the requirements for these items. If you're not in the US you need to check the local code requirements.

Regards,

DB

 

[dik]

See the link...

https://www.usg.com/content/dam/USG...-panels-cavity-shaft-wall-brochure-en-can.pdf

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[stripez]

Dbronson,

stripez:

I'm guessing from the photo you aren't in the US? In the US jurisdictions use the International Building Code (IBC). There's a big difference between a "fire wall" and a "fire barrier". I suspect you may only need a fire barrier. Chapter 7 of the IBC covers the requirements for these items. If you're not in the US you need to check the local code requirements.

Regards,

DB

Our code is the following

"The provision of a fully functional sprinkler system and the installation of other fire-retardant or fire suppression devices in the case of commercial, institutional and industrial buildings/structures may allow firewall construction for up to 70% of the total perimeter of the property lines provided that the described setbacks, yards and courts fronting the Road Right-Of-Way (RROW) are first fully complied with..."

Since the client doesn't have sprinkler system or fire suppression devices. We need Firewall at 3 sides since it is a commercial building. Now are cement board like in my original photo considered a Firewall, or Fire Barrier? What materials can only be a Firewall? Is it only either full concrete or masonry hollow blocks? Or is there any cladding or shalfwall that can be considered a Firewall too? Or are they Fire Barrier only?

 

[stripez]

Anyway. What I really need to put is a FireWall. And only concrete or masonry walls are considered FireWall.

This is the photo years ago before the 1 meter high parapet was added. The distance between the 10mm (0.4") rebars is 600mm (23.62"). This is kinda wide.

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What if I'd weld new 10mm (0.4") rebars to the existing metal frame and put solid concrete (or masonry blocks)? Has anyone tried anything like this?

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[dik]

Were you able to sort this out?

didn't know that about firewalls... will check; I was't sure. Since they are external, (usually for proximity) or internal (for building area), I've only constructed them in concrete or masonry (Canada permits only concrete or masonry, just found out. Does cement board work?). On a recent project in Winnipeg, the AHJ allowed a 2 hour non-combustible construction (CFS and GWB), due to proximity of adjacent building. I've usually needed 4 hour walls... It sometimes becomes a challenge to maintain the integrity. As long as the separation has integrity throughout the fire and extends past the structure, I didn't realise there was a restriction on the material.

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[phamENG]

To answer your question about reinforcing, yes, you can do that. You need special rebar with chemistry suitable for welding. In the us, it's ASTM 706, as opposed to the more common (in my market) 615. Drill and epoxy into the concrete. Be careful at the column - don't want to go cutting through your ties.

I'd be careful about doing this, though. As skeletron mentioned, it will stiffen that wall and could alter the behavior of the structure in an earthquake. You may be able to avoid securing the rebar at the top, and instead weld a series of vertical plates or angles that would keep the wall from falling over, but also allows the steel frame to deflect and move as designed.

 

[stripez]

I found out cement board doesnt even have 1 hour fire rating as it can make heat pass through.

So i definitely have to put masonry blocks as Firewall.

What if i remove all the steel frame. And chip off the parapet and columm to make the internal rebars visible and add new rebars to make traditional wall. Would that work? My worry is if i use a chipping hammer. Wont the old rebars vibrate and crack. Also i found out the distance between rebars is 600mm. Is it so wide?

Please share technique how to chip of the parapet and column to add more rebars or dowels to put traditonal masonry blocks. Remember ill remove all the existing metal frame. Also the column is not supporting any floors above it, just metal roof so even if its 25% smaller it would still work.

 

[dik]

With multiple layers of conc board... aren't they additive? like GWB?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[stripez]

https://www.jameshardie.com/product...cal-documents/fire-prevention-faq?loc=refresh

Here is what it says

"Are your products 1-hour fire-rated?
While JamesHardie® products will not ignite when exposed to direct flame or contribute fuel to a fire, heat will transfer through them. Because of this, the product itself is not 1-hour fire rated."

As hot as cooking pan on other side enough to ignite objects? How hot?

I need 3 to 4 hour fire rating. Seems no other way except to remove the entire metal frame and chip the parapet and column to get development length for the rebars. And add masonry blocks.

Also what is most important is not necessarily welding the old and new rebars together but just have enough development length. The strength of the rebars in wall is just making section by section stiff and not about have welded rebars. Isnt it?

 

[stripez]

Here is more layout so others can help me.

This is when it's closed (which is status at present).

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This is top of it. The cement board framing is connected to the I-beam by the blue label (L bracket and straight).

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When opened as shown originally (photo before it was closed).

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My question. There is opening on top of roof when I remove flashing. Can I just pour sands into the gap inside? How heat resistant is sand? Imaging the layer as 9mm cement board outside, 2 inches sand, 6mm cement board inside.

 

[dik]

Can you fill the masonry voids with a non-combustible filler (used to use zonalite, but asbestos content, now) to give you the FRR of a 6" (5-1/2") concrete wall?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik