combustible material in type I and II construction 603.1

[John Gallo]

I have a question to add to this. A coworker and I do not see eye to eye on this subject. In a Type 1 & 2 noncombustible, he is saying the Jack stud "can" be of combustible material. Because under exceptions in IBC and IFC, 603.1 exception #14 says "Blocking" such as for handrails, millwork, cabinets and window and "Door frames" does not have to be noncombustible. Now since the door can be of "combustible material" under the IBC and IFC 603.1 Exception #6. He says, The Jack stud is the "Blocking"/Backing for the door so it, in turn, dose not have to be of noncombustible material.

Now i don't see a Jack stud as a Blocking. Blocking Definition says "Uses include filling, spacing, joining, or reinforcing members. Blocking is typically made from short off-cuts or defective, warped pieces of lumber. The term Blocking is also sometimes used by people in construction to refer to discontinuous shims or spacers." I see it as part of the framing/structure as it holds the header and is connected to the king stud that is also made up of noncombustible material. Now he is a seasoned inspector of 40 years. I am only 1 year into being an inspector. So he says, you understand it your way and i understand it my way. I am not trying to ruffle feathers or step on toes, but if i fail someone i want to make sure i can back it up and site the code directly. What is your thoughts on this? "First post by the way"

 

[Hyrax4978]

My opinion only:
If its load bearing, i would say it should be metal. We typically oversize the opening just a bit to allow blocking to be installed between the frame and the studs. Blocking is easiest installed in a full length although its not needed the full length. So even though its not needed full length it might look like a jack stud if its installed full length.
If its not load bearing, I see allot of interior partitions being installed with just a clip from the king to a couple of horizontal members over the opening. No jack studs at all. right or wrong it happens ALLOT. in this scenario i would say its blocking because the horizontal members are clipped to the king stud.

Basically my opinion is if its for holding the header, its structural, if its for fastening of the frame, its blocking.

 

[steveray]

If it is a true "bearing jack"....no....If it truly is blocking for installing wooden jambs.....It's good...

 

[jar546]

bump....
looking for more opinions.

 

[steveray]

As there is no limit to the amount of blocking you can have, even if it were a full height stud, technically it should be allowed....IMO....Unless it is structural....You do have to consider at some point if the cavity is large enough, it does become a concealed combustible space per NFPA 13 and would require sprinkler protection, but I believe that would have to be a wall wider than 6"...

 

[ICE]

I have a question to add to this. A coworker and I do not see eye to eye on this subject. Now he is a seasoned inspector of 40 years. I am only 1 year into being an inspector. So he says, you understand it your way and i understand it my way. I am not trying to ruffle feathers or step on toes, but if i fail someone i want to make sure i can back it up and site the code directly. What is your thoughts on this?

I'm more half baked than seasoned but I can relate to your conundrum. I am working with a new inspector. He learns from everybody and I learn from him.
I remember my early years and more than a few odd code interpretations.....that persists to this day. You are trying to not ruffle feathers....go ahead and litter the floor.

 

[JBI]

I have to agree with the majority here.
Blocking is not load bearing, a jack stud supports a header and is load bearing.
A jack stud is an integral part of the load path, blocking is not.

 

[mtlogcabin]

A jack stud is part of the wall framing and is required to be Fire-retardant treated
2012 IBC
603.1 Allowable materials.
Combustible materials shall be permitted in buildings of Type I or II construction in the following applications and in accordance with Sections 603.1.1 through 603.1.3:
1. Fire-retardant-treated wood shall be permitted in:
1.1. Nonbearing partitions where the required fire-resistance rating is 2 hours or less.
1.2. Nonbearing exterior walls where fire-resistance rated construction is not required.

Blocking is minimal size material installed within or between framing members to aid in the attachment of finished products it does not replace framing members

Using the logic in the OP of the 40 year seasoned inspector all non-structural studs are just blocking for attaching the gypsum board to.

 

[John Gallo]

Great and thank you guys! This helps out.

 

[Steve Vetter]

Thank goodness they fixed the typo error in 2018 that existed in 2015 and 2012 for 603.1

 

[John Gallo]

What was the typo error steve?

 

[Steve Vetter]

First 2015:

603.1 Allowable Materials

Combustible materials shall be permitted in buildings of Type I or II construction in the following applications and in accordance with Sections 603.1.1 through 603.1.3:

1. Fire-retardant-treated wood shall be permitted in:

1.1. Nonbearing partitions where the required fireresistance rating is 2 hours or less.

1.2. Nonbearing exterior walls where fire-resistance-rated construction is not required.

1.3. Roof construction, including girders, trusses, framing and decking.

Exception: In buildings of Type IA construction exceeding two stories above grade plane, fire-retardant-treated wood is not permitted in roof construction where the vertical distance from the upper floor to the roof is less than 20 feet (6096 mm).

2. Thermal and acoustical insulation, other than foam plastics, having a flame spread index of not more than 25.

Exceptions:

1. Insulation placed between two layers of noncombustible materials without an intervening airspace shall be allowed to have a flame spread index of not more than 100.

2. Insulation installed between a finished floor and solid decking without intervening airspace shall be allowed to have a flame spread index of not more than 200.

3. Foam plastics in accordance with Chapter 26.

4. Roof coverings that have an A, B or C classification.

5. Interior floor finish and floor covering materials installed in accordance with Section 804.

6. Millwork such as doors, door frames, window sashes and frames.

ETC..........

As written and numbered exceptions are for #2, of course not!


Second 2018 finally corrected:

603.1 Allowable materials


Combustible materials shall be permitted in buildings of Type I or II construction in the following applications and in accordance with Sections 603.1.1 through 603.1.3:

1. 
   Fire-retardant-treated wood shall be permitted in:
   1. 1.1. Nonbearing partitions where the required fire-resistance rating is 2 hours or less.
   2. 1.2. Nonbearing exterior walls where fire-resistance-rated construction is not required.
   3. 
      1.3. Roof construction, including girders, trusses, framing and decking.
      
      Exception: In buildings of Type IA construction exceeding two stories above grade plane, fire-retardant-treated wood is not permitted in roof construction where the vertical distance from the upper floor to the roof is less than 20 feet (6096 mm).
      
   4. 1.4. Balconies, porches, decks and exterior stairways not used as required exits on buildings three stories or less above grade plane.
2. 
   Thermal and acoustical insulation, other than foam plastics, having a flame spread index of not more than 25.
   
   
   Exceptions:
   1. Insulation placed between two layers of noncombustible materials without an intervening airspace shall be allowed to have a flame spread index of not more than 100.
   2. Insulation installed between a finished floor and solid decking without intervening airspace shall be allowed to have a flame spread index of not more than 200.
   
   
3. Foam plastics in accordance with Chapter 26.
4. Roof coverings that have an A, B or C classification.
5. Interior floor finish and floor covering materials installed in accordance with Section 804.
6. Millwork such as doors, door frames, window sashes and frames.

ETC........


I am not a terribly smart guy; neither are the people proofreading the codes apparently!