membrane penetration elevator shaft

[hans@dha-architects.]

I've got an elevator shaft going up in a three story apartment building in the coming months, question regarding membrane penetrations - we have a triple LVL in one wall of the shaft which at the moment is 6" CH studs, but may switch to 2x6's framing, anyway, the penetration would be on each side of the side walls where the beam comes out - 713.8 says structural elements such as beams and joists where protected in accordance with 714 shall be permitted to penetrate the shaft, but 714 only addresses electrical boxes, conduit, etc., so how would they be protected? or would this fall under 707.5.1 for supporting construction (fire barriers) where supporting construction of 1 hour fire barriers of VB (which we are) is not required to be fire resistant rated by other sections of the code (it's not).......so aside from firecaulking around the penetration, can I assume this penetration is ok as is? I have floor trusses hanging off beams at each floor in the shaft, but I can us Simpsons fire rated hangers that allow sheetrock behind them so it'll be continuous at the floor framing. I'm waiting for approval from the state for our modification to fall under the old code, so the building official won't even look at drawings until we get that approval, so hence me not asking him

 

[mtlogcabin]

713.8.1 Prohibited penetrations.
Penetrations other than those necessary for the purpose of the shaft shall not be permitted in shaft enclosures.

You will have to enclose the triple LVL in a fire barrier assembly equal to the shaft assembly

 

[hans@dha-architects.]

713.8.1 Prohibited penetrations.
Penetrations other than those necessary for the purpose of the shaft shall not be permitted in shaft enclosures.

You will have to enclose the triple LVL in a fire barrier assembly equal to the shaft assembly

I read the exception for supporting construction too fast, you are correct, ok not a huge deal, I've got a few options, either make the beam non-continuous thru the shaft and add posts outside the shaft (i'd rather not), wrap with two layers of sheetrock or maybe even coat it in intumescent paint.......then again, the sheetrock around the shaft will have long burned thru by the time that LVL is compromised if I had to guess

 

[steveray]

Hans...if it is V-A isn't the beam already protected 1 hour? I think it is the biggest mistake going now in the IBC but you can pretty much ruin the exit enclosures and shafts now....Because some people couldn't enforce it as written.....

 

[hans@dha-architects.]

Hans...if it is V-A isn't the beam already protected 1 hour? I think it is the biggest mistake going now in the IBC but you can pretty much ruin the exit enclosures and shafts now....Because some people couldn't enforce it as written.....

no, we're VB

 

[Inspector Gadget]

Not familiar with ICC/IBC Codes, but in Canada, LVL beams can be assigned a fire-resistance rating under Appendix D.
In fact, I just signed off on a change in a renovation where the engineer calculated an LVL to have a 72-minute FRR, which consequently means it need not be wrapped with Type X material to achieve a required 60-min minimum FRR.

 

[steveray]

Equating it with heavy timber....because it sorta is....

 

[mtlogcabin]

Not really and the code recognizes that in Section 2304.11 with limitations on the different materials and sizes and how they are used.

2304.11 Heavy timber construction.
Where a structure, portion thereof or individual structural elements are required by provisions of this code to be of heavy timber, the building elements therein shall comply with the applicable provisions of Sections 2304.11.1 through 2304.11.4. Minimum dimensions of heavy timber shall comply with the applicable requirements in Table 2304.11 based on roofs or floors supported and the configuration of each structural element, or in Sections 2304.11.2 through 2304.11.4. Lumber decking shall be in accordance with Section 2304.9.

 

[steveray]

Hence ...sorta, it shouldn't really act much different, but isn't technically covered...:

 

[hans@dha-architects.]

Hence ...sorta, it shouldn't really act much different, but isn't technically covered...:

View attachment 9779

so it appears with a triple LVL (5.25" x 14"), I would not need to protect it?

 

[Paul Sweet]

It would have to be a 5 1/4" x 14" LVL. You can't count thinner pieces fastened together; it has to be one solid piece.

 

[hans@dha-architects.]

It would have to be a 5 1/4" x 14" LVL. You can't count thinner pieces fastened together; it has to be one solid piece.

ah yes, I was wondering about that, so I either have to change it to a PSL which would be one piece, or wrap the triple LVL in one layer 5/8" type x - per table 722.7.1(1)?

 

[steveray]

see the table I posted above hans....With glu-lam or SCL listed...Code doen't actually say whether they could be "field assembled" or not.....

[BS] STRUCTURAL COMPOSITE LUMBER. Structural
member manufactured using wood elements bonded together
with exterior adhesives. Examples of structural composite
lumber are:
Laminated strand lumber (LSL). A composite of wood
strand elements with wood fibers primarily oriented along
the length of the member, where the least dimension of the
wood strand elements is 0.10 inch (2.54 mm) or less and
their average lengths not less than 150 times the least
dimension of the wood strand elements.
Laminated veneer lumber (LVL). A composite of wood
veneer sheet elements with wood fibers primarily oriented
along the length of the member, where the veneer element
thicknesses are 0.25 inches (6.4 mm) or less.
Oriented strand lumber (OSL). A composite of wood
strand elements with wood fibers primarily oriented along
the length of the member, where the least dimension of the
wood strand elements is 0.10 inches (2.54 mm) or less and
their average lengths not less than 75 times and less than
150 times the least dimension of the strand elements.
Parallel strand lumber (PSL). A composite of wood
strand elements with wood fibers primarily oriented along
the length of the member where the least dimension of the
wood strand elements is 0.25 inches (6.4 mm) or less and
their average lengths not less than 300 times the least
dimension of the wood strand elements.

 

[hans@dha-architects.]

see the table I posted above hans....With glu-lam or SCL listed...Code doen't actually say whether they could be "field assembled" or not.....

[BS] STRUCTURAL COMPOSITE LUMBER. Structural
member manufactured using wood elements bonded together
with exterior adhesives. Examples of structural composite
lumber are:
Laminated strand lumber (LSL). A composite of wood
strand elements with wood fibers primarily oriented along
the length of the member, where the least dimension of the
wood strand elements is 0.10 inch (2.54 mm) or less and
their average lengths not less than 150 times the least
dimension of the wood strand elements.
Laminated veneer lumber (LVL). A composite of wood
veneer sheet elements with wood fibers primarily oriented
along the length of the member, where the veneer element
thicknesses are 0.25 inches (6.4 mm) or less.
Oriented strand lumber (OSL). A composite of wood
strand elements with wood fibers primarily oriented along
the length of the member, where the least dimension of the
wood strand elements is 0.10 inches (2.54 mm) or less and
their average lengths not less than 75 times and less than
150 times the least dimension of the strand elements.
Parallel strand lumber (PSL). A composite of wood
strand elements with wood fibers primarily oriented along
the length of the member where the least dimension of the
wood strand elements is 0.25 inches (6.4 mm) or less and
their average lengths not less than 300 times the least
dimension of the wood strand elements.

good point, I guess if LVL's and LSL's are mentioned, they're typically 1.75", so one could infer that multiple members can be used to achieve the minimum size, but as you said the code doesn't specifically say that......in the end, it's not a huge deal if I have to wrap the beam in sheetrock, we're talking about a 6' section on each side of the shaft and just use simpsons fire wall hangers.....funny, that's a new section added to the code, I'm actually using the previous code for this project, I would imagine I could reference this section since it's not addressed in the old code

 

[steveray]

good point, I guess if LVL's and LSL's are mentioned, they're typically 1.75", so one could infer that multiple members can be used to achieve the minimum size, but as you said the code doesn't specifically say that......in the end, it's not a huge deal if I have to wrap the beam in sheetrock, we're talking about a 6' section on each side of the shaft and just use simpsons fire wall hangers.....funny, that's a new section added to the code, I'm actually using the previous code for this project, I would imagine I could reference this section since it's not addressed in the old code

Absolutely...and if Joel doesn't buy it you can get it formally through the State...

 

[mtlogcabin]

so one could infer that multiple members can be used to achieve the minimum size,

And how are you connecting the multiple members together? Will the connection pass a one-hour assembly test?

Just playing devil's advocate here so you are not zeroed in on meeting just the size of the lumber. Remember heavy timber works because of the charring effect on a large single piece of lumber essentially does not reduce the structural strength significantly. Not sure if that would apply to multiple 1.75" LVL's fastened together. You may have to provide a little more documentation to CYA