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Combustible Knee Wall Framing in Type IIA Construction?

jar546

jar546

CBO
Joined
Oct 16, 2009
Messages
12,768
Location
Not where I really want to be
Existing building, Type IIA, no fire-sprinkler system. Building consists of B & A use and occupancy with the photo taken in an R2 condo.

This framing violated the IBC, but my suspicion is that some of you will allow it, even though it is clearly a violation. This is combustible, nominal lumber that is not fire-treated.

What are your thoughts on this?

IMG_6612.JPG
 
MY OPINION is that these walls aren't really what the code had in mind for the "building elements" in t601, however I refrain from reading more or less into the code as much as possible. In this case I think with very little work a way could be found to leave it and still meet the code. I would do my best to help them find a way to fit it in the code and be on my way. I might suggest 603.1 #11, so using prescriptive fire resistance ratings in 722.6 I don't think it would be a bridge too far. 1/2" type X with mineral wool would get you there. I realize an R2 condo isn't included in #11, but I don't think there is any more wood framing in those 1/2 walls than there could be blocking in any wall, which is allowed by #14 without fire rating. This is just me trying to find a way to "yes".
 
Canadian Code would allow this. Millwork/Cabinets [NBC 3.1.5.9] and minor components like blocking and "similar" are accepted [NBC 3.1.5.2.]

I'd also rely on this:

1710862483624.png
Kinda interested to see what the 'Murican Codes would allow.
 
Sifu said:
MY OPINION is that these walls aren't really what the code had in mind for the "building elements" in t601
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I agree with your opinion. It will be encased in gypsum board and will have less fire loading then the couch that is in the picture.
There is the written code and there is the intent of the code. We are charged with clarifying the intent of the code while enforcing the provisions of the code.


[A] 104.1 General.
The building official is hereby authorized and directed to enforce the provisions of this code. The building official shall have the authority to render interpretations of this code and to adopt policies and procedures in order to clarify the application of its provisions. Such interpretations, policies and procedures shall be in compliance with the intent and purpose of this code. Such policies and procedures shall not have the effect of waiving requirements specifically provided for in this code.

[BG] BUILDING ELEMENT. A fundamental component of building construction, listed in Table 601, which may or may not be of fire-resistance-rated construction and is constructed of materials based on the building type of construction.
 
Just curious, but are the doors and cabinets made out of metal? I suppose I could look it up in the code but asking the question is so much easier.
 
I once had a dispute with a fire marshal on a project that was done without a permit. Photos were provided to us and I commented that the partitions were not permitted to be of combustible construction. He argues and said that they could be because they weren't bearing. I won the argument. However, IMO, a partition, dividing spaces, from floor to ceiling are covered by t601, whereas a 1/2 wall, not dividing spaces could be seen as not being applicable. Note that ch. 16 has no structural properties assigned unless 6' in height. This isn't a hill I would die on either way.
 
Sifu said:
a partition, dividing spaces, from floor to ceiling are covered by t601, whereas a 1/2 wall, not dividing spaces could be seen as not being applicable
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Where is a knee wall excluded from code requirements?

So now the receptacle in the knee wall caught fire, and instead of going nowhere because it was encapsulated on both sides with drywall and metal studs, it catches the combustible framing on fire, which then heats up and catches the cabinets on fire?

What is so difficult about requiring fire-treated lumber if they choose to use wood? Why are building inspectors choosing to ignore code requirements? Who benefits? Who is at risk?
 
jar546 said:
Where is a knee wall excluded from code requirements?

So now the receptacle in the knee wall caught fire, and instead of going nowhere because it was encapsulated on both sides with drywall and metal studs, it catches the combustible framing on fire, which then heats up and catches the cabinets on fire?

What is so difficult about requiring fire-treated lumber if they choose to use wood? Why are building inspectors choosing to ignore code requirements? Who benefits? Who is at risk?
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Why so argumentative? Nothing difficult about it. Nowhere did I say the knee wall was excluded, I said "could be seen as not applicable". Just providing my thoughts since you asked. I thought you were genuinely interested in them.

FWIW, the same fire you provide as an example could happen in receptacle installed in the back of a cabinet were there no wall, only in the possible conditions I proposed, it would be limited by the 1/2" type X, and mineral wool.

My understanding is that the building elements in t601 are not rated to provide separation, rather they are related to the ability of the element to maintain structural integrity in a fire event. Those knee walls have no structural integrity to maintain, which is why I said "could be seen as not applicable". Was an inspector ignoring the code requirement, or just seeing differently than you?

Just my thoughts.
 
Sifu said:
Why so argumentative? Nothing difficult about it. Nowhere did I say the knee wall was excluded, I said "could be seen as not applicable". Just providing my thoughts since you asked. I thought you were genuinely interested in them.
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My response had nothing to do with your post. Not sure why you personalized it as though it was specifically for you.
 
jar546 said:
This framing violated the IBC,
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Is this really "framing" under the code? If it was built offsite and assembled in the building like most counters and cabinets what code section would you quote when writing them up?
jar546 said:
What is so difficult about enforcing this code?
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Not difficult at all if you understand the intent of the code section.
The IBC establishes minimum requirements to follow.
The IEBC provide flexibility to achieve compliance.

IEBC 2018
[A] 101.3 Intent.
The intent of this code is to provide flexibility to permit the use of alternative approaches to achieve compliance with minimum requirements to safeguard the public health, safety and welfare insofar as they are affected by the repair, alteration, change of occupancy, addition and relocation of existing buildings.
I
BC 2018
[A] 101.3 Intent.
The purpose of this code is to establish the minimum requirements to provide a reasonable level of safety, public health and general welfare through structural strength, means of egress facilities, stability, sanitation, adequate light and ventilation, energy conservation, and safety to life and property from fire, explosion and other hazards, and to provide a reasonable level of safety to fire fighters and emergency responders during emergency operations.
 
mtlogcabin said:
Is this really "framing" under the code? If it was built offsite and assembled in the building like most counters and cabinets what code section would you quote when writing them up?
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But it wasn't. It was built on-site.

mtlogcabin said:
Not difficult at all if you understand the intent of the code section.
The IBC establishes minimum requirements to follow.
The IEBC provide flexibility to achieve compliance.
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Intent? The intent is clear in IEBC 702.7. New work is per the IBC. This is a high-rise building with an aging population and there is no wiggle room for the code. In this case of the photo I posted. The knee walls were removed and reframed with fire-treated lumber. It was not that difficult to handle. We failed the inspection, cited the code and the contractor changed it to comply. I find that much easier than trying to find a reason not to enforce something & convince myself I don't have to.

702.7 Materials and methods.​

New work shall comply with the materials and methods requirements in the International Building Code, International Energy Conservation Code, International Mechanical Code and International Plumbing Code, as applicable, that specify material standards, detail of installation and connection, joints, penetrations and continuity of any element, component or system in the building.
 
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