# Fire Rated Construction



## Kanzas (Jan 10, 2012)

Where in the IBC 2009 does it state that fire rated assemblies in the Gypsum Association Fire Resistance Design Manual meet the requirements for IBC fire rated assemblies? Thanks.


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## mtlogcabin (Jan 10, 2012)

703.2 Fire-resistance ratings.

The fire-resistance rating of building elements, components or assemblies shall be determined in accordance with the test procedures set forth in ASTM E 119 or UL 263 or in accordance with Section 703.3.

They have been tested to the applicable standards


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## Kanzas (Jan 10, 2012)

Thank you, mtlogcabin


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## mtlogcabin (Jan 10, 2012)

*From the GA Manual*

*FIRE RESISTANCE TESTS*
​All fire-resistance classifications described in thisManual are derived from full-scale fire tests conductedin accordance with the requirements of ASTM E 119 orCAN/ULC-S101 (as amended and in effect on the dateof the test) by recognized independent laboratories.Fire-resistance classifications are the results of testsconducted on systems made up of specific materials put
​together in a specified manner.


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## mark handler (Jan 10, 2012)

IBC 2009

TABLE 721.1(1)

Footnote

m. Generic fire-resistance ratings (those not designated as PROPRIETARY* in the listing) in GA 600 shall be accepted as if herein listed.

TABLE 721.1(2)

Footnote

q. Generic fire-resistance ratings (those not designated as PROPRIETARY* in the listing) in the GA 600 shall be accepted as if herein listed.


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## garrett (Jan 11, 2012)

It is unfortunate that the GA manual lacks assembly details for intersections.

For example, where a rated wall is intersected by a non-rated wall or by a non-rated floor assembly.

It seems a lot of designers just invent details that might seem plausible,

But have not actually been tested and listed.

Or am I missing something?


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## mark handler (Jan 11, 2012)

garrett said:
			
		

> It is unfortunate that the GA manual lacks assembly details for intersections.For example, where a rated wall is intersected by a non-rated wall or by a non-rated floor assembly.
> 
> It seems a lot of designers just invent details that might seem plausible,
> 
> ...


Many of the manufactures have rated to nonrated assemblies.

The GA600 is Gypsum Association Fire Resistance Design Manual not a Gypsum detail manual.


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## brudgers (Jan 11, 2012)

garrett said:
			
		

> It is unfortunate that the GA manual lacks assembly details for intersections.  For example, where a rated wall is intersected by a non-rated wall or by a non-rated floor assembly. It seems a lot of designers just invent details that might seem plausible,  But have not actually been tested and listed. Or am I missing something?


  UL lacks details for intersections as well...what's your point?


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## garrett (Jan 11, 2012)

Well, for example,

how does one maintain the fire-resistive rating of a multi-story rated wall when there is a non-rated floor/ceiling assembly that intersects it and bears on it at intermediate levels. This occurs at townhouses sharing a common wall.

Seems simple enough, but researching precedents I find that the majority of the time architects details are not based on an actual tested assembly, but something that is invented to look reasonable enough.

It would be nice if UL had some drawings of conditions like these that are tested.


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## mtlogcabin (Jan 11, 2012)

> how does one maintain the fire-resistive rating of a multi-story rated wall when there is a non-rated floor/ceiling assembly that intersects it and bears on it at intermediate levels. This occurs at townhouses sharing a common wall.


You can't and therfore that dseign would not be permitted


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## mark handler (Jan 11, 2012)

garrett said:
			
		

> Well, for example, how does one maintain the fire-resistive rating of a multi-story rated wall when there is a non-rated floor/ceiling assembly that intersects it and bears on it at intermediate levels. This occurs at townhouses sharing a common wall.
> 
> Seems simple enough, but researching precedents I find that the majority of the time architects details are not based on an actual tested assembly, but something that is invented to look reasonable enough.
> 
> It would be nice if UL had some drawings of conditions like these that are tested.


Once again, refer to manufactures Area Separation Fire Wall Details. If you test an assembly as you describe, it will fail.


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## garrett (Jan 11, 2012)

mtlogcabin said:
			
		

> You can't and therfore that dseign would not be permitted.


What do you mean, "you can't?"

Are you saying that if the wall is fire-rated, then the floor/ceiling assembly must be rated too?

What is your suggested alternative?



			
				mark handler said:
			
		

> Once again, refer to manufactures Area Separation Fire Wall Details. If you test an assembly as you describe, it will fail.


The situation I describe is NOT an Area Separation Fire Wall, it is a 1-hour fire-resistive common wall, per R302.2, Excpetion.

An Area Separation Fire Wall is a completely different thing.

There are some published details out there for what I describe, but not too many, and mostly by manufacturers of engineered lumber products.


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## mark handler (Jan 11, 2012)

How in the world do you think you can end a 1-hour fire-resistive common wall in an unrated floor system

It doesnt work, the fire wall must extend to the foundation, without "holes" in it.


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## mtlogcabin (Jan 11, 2012)

2009 IRC

R302.2.1 Continuity.

The fire-resistance-rated wall or assembly separating townhouses shall be continuous from the foundation to the underside of the roof sheathing, deck or slab.......

What you describe is a membrane penetration and will not meet the requirements of R302.4.1.

R302.4.2 Membrane penetrations.

Membrane penetrations shall comply with Section R302.4.1.


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## gbhammer (Jan 11, 2012)

:agree Mark and mt are absolutely correct.


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## garrett (Jan 11, 2012)

R302.2.1 Continuity says rated "wall or assembly" shall be continuous, 

it does not say that you can't change from one type of assembly to another as you go up.

The critical element is that the fire-resistance is continuous, but the assembly may change.

Are you saying they need to be balloon-framed? No bearing on the common-wall? No beam-pockets allowed either? I disagree with that interpretation.

R302.4.2 Membrane penetrations is written for recessed fixtures, not for changes in assembly from one type to another.

I interpret that one may use a continuous rim-board assembly, with continuous 5/8" Type X Gyp. on each side that provides continuous fire-resistive rating. No "holes" in it.

Structural independence is not required.


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## mark handler (Jan 11, 2012)

GARRRTT

Your "wall or assembly" as shown is not continuous. The wall ends at the floor, then starts again.

One option is to Provide solid blocking, full width of the plate

Another option is to go to the trus joit website and use an approved detail

It is a good thing the planchecker redflagged this detail


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## mtlogcabin (Jan 11, 2012)

I have seen this design approach before and it could work if it provides a one-hour protection from unit to unit.

1 The fire side is from the ceiling assembly. One layer of Type X has 40 minutes of assigned protection. How much time do you get for the LVL rim board?

2 What time frame is given to the second floor 2X sill plate?

Nobody around here answered those questions?

 They wanted to install 2 layers of Type X which would work, but in the field came up short on the minimum bearing requirements for the I-Joist

May look good on paper but difficult to construct.


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## brudgers (Jan 11, 2012)

garrett said:
			
		

> Well, for example, how does one maintain the fire-resistive rating of a multi-story rated wall when there is a non-rated floor/ceiling assembly that intersects it and bears on it at intermediate levels. This occurs at townhouses sharing a common wall.


My recommendation would be to hire an architect familiar with the typology.


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## mark handler (Jan 11, 2012)

brudgers said:
			
		

> My recommendation would be to hire an architect familiar with the typology.


:agree

I   agree


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## garrett (Jan 11, 2012)

Most architects, including those "familiar with the typology" do not get it right, they make it up.

Your response is basically saying you don't know the answer.

So if you rely on an architect with some sort of secret insight into the issue, how are building officials supposed to evaluate the proposed design?

I appreciate more constructive advice.


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## mark handler (Jan 11, 2012)

garrett said:
			
		

> I appreciate more constructive advice.


You were given constructive advice which you chose to ignor.

It did not fit your idea.

Side note  your assembly  probably will not meet your SOUND TRANSMISSION requirements


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## garrett (Jan 11, 2012)

Okay, but the CRC (based on 2009 IRC) does not have mandatory sound transmission requirements. But of course we want to provide a decent level of separation. It is a staggered stud wall assembly.

"APPENDIX K

SOUND TRANSMISSION

The provisions contained in this appendix are not mandatory unless specifically referenced in the adopting ordinance.

(Note: See Section 1207 “Sound Transmission” of the California Building Code, Title 24, Part 2, for requirements applicable to structures in this code.)

SECTION AK 101

GENERAL

AK101.1 General. Wall and floor-ceiling assemblies separating dwelling units including those separating adjacent townhouse units shall provide air-borne sound insulation for walls, and both air-borne and impact sound insulation for floor-ceiling assemblies..."


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## brudgers (Jan 12, 2012)

mark handler said:
			
		

> You were given constructive advice which you chose to ignor.


  I think he is practicing as or like an architect...and the advice would have been better directed to the Owner.


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## brudgers (Jan 12, 2012)

mtlogcabin said:
			
		

> I have seen this design approach before and it could work if it provides a one-hour protection from unit to unit. 1 The fire side is from the ceiling assembly. One layer of Type X has 40 minutes of assigned protection. How much time do you get for the LVL rim board? .


  After 40 minutes your question becomes irrelevant as the structure pulls itself apart due to the collapse of the unprotected floor system.


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## mark handler (Jan 12, 2012)

garrett said:
			
		

> Okay, but the CRC (based on 2009 IRC) does not have mandatory sound transmission requirements. But of course we want to provide a decent level of separation. It is a staggered stud wall assembly.


California Administrative Code, Title 25, Chapter 1, Subchapter 1; Article 4. Noise Insulation Standards

Ask the AHJ you will find they have adopted Appen. K or they have there own Noise Standards. or the state defalt or California Administrative Code, Title 25, Chapter 1, Subchapter 1; Article 4. Noise Insulation Standards, goes into play.

You must have a 50 min STC By state law


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## mtlogcabin (Jan 12, 2012)

brudgers said:
			
		

> After 40 minutes your question becomes irrelevant as the structure pulls itself apart due to the collapse of the unprotected floor system.


Good point but not a code issue.

The majority of wood 2 story homes floor systems are constructed that way. Might be even less than 40 minutes since most SFR do not have Type X gypsum board installed on the ceilings and we know the I-Joist will not last but a few minutes once exposed to the fire.

The floor system should run parrallel to the 2 hour wall


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## gbhammer (Jan 12, 2012)

mtlogcabin said:
			
		

> Good point but not a code issue. The majority of wood 2 story homes floor systems are constructed that way. Might be even less than 40 minutes since most SFR do not have Type X gypsum board installed on the ceilings and we know the I-Joist will not last but a few minutes once exposed to the fire.
> 
> The floor system should run parrallel to the 2 hour wall


:agree Why would anyone do it any other way. Makes no sense to penetrate the rated wall with joist.


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## Architect1281 (Jan 12, 2012)

#1 ICC Codes do not certify rating

#2 ICC Does describe CONTINUITY

#3 Change your design Professional

#4 Mark is much more tolerant than me - and he is correct


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## Fort (Jan 12, 2012)

See here for examples:

http://woodbywy.com/literature/1500.pdf


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## gbhammer (Jan 12, 2012)

Welcome to the forum Fort. Nice post for your first post. Thanks and hope to see much more from you.


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## brudgers (Jan 12, 2012)

mtlogcabin said:
			
		

> Good point but not a code issue.  The majority of wood 2 story homes floor systems are constructed that way. Might be even less than 40 minutes since most SFR do not have Type X gypsum board installed on the ceilings and we know the I-Joist will not last but a few minutes once exposed to the fire.   The floor system should run parrallel to the 2 hour wall


  It's relevant if one is trying to achieve fire separation as you mentioned in your post I quoted.


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## mark handler (Jan 12, 2012)

Fort said:
			
		

> See here for examples:http://woodbywy.com/literature/1500.pdf


Welcome Fort.

Please note, most of those systems are Rated Floor/Ceiling systems. The OP is a rated wall interupted with a unrated FC system


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## brudgers (Jan 12, 2012)

gbhammer said:
			
		

> :agree Why would anyone do it any other way. Makes no sense to penetrate the rated wall with joist.


  Obviously, you have never designed a townhouse...property line to property line is typically the shorter span by a significant amount.


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## gbhammer (Jan 12, 2012)

brudgers said:
			
		

> Obviously, you have never designed a townhouse...property line to property line is typically the shorter span by a significant amount.


I am not a DP just a lowly AHJ, and I am happy that your experience with shorter spans is your problem and not mine.


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## brudgers (Jan 12, 2012)

gbhammer said:
			
		

> I am not a DP just a lowly AHJ, and I am happy that your experience with shorter spans is your problem and not mine.


  Nothing lowly about being a code official - and having worked on many many hundreds of townhouse units, spanning the short direction hardly presents a unique challenge...it's only those lacking experience with the typology who struggle.


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## garrett (Jan 12, 2012)

How would you do it brudgers?

Seems like you know, and it is apparent that the issue is a struggle for many,

not only those with limited experience. There are not any published examples that I could find.

The details in the linked PDF do show some viable options, but requires a rated floor/ceiling, which seems easy enough,

but then you have to maintain that floor/ceiling rating, so you got to think about recessed light fixtures, etc...

and it seems like the whole intent is a continuous fire resistive rated wall, not a floor/ceiling, so perhaps in that regard there should be a better solution.

What do you say about the similar continuous rim-board strategy, but add solid blocking at the face of studs with 5/8" type x.

http://s13.postimage.org/66f8c3g7r/Screen_shot_2012_01_12_at_4_29_22_PM.png


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## brudgers (Jan 12, 2012)

garrett said:
			
		

> How would you do it brudgers?


  With a signed contract and a retainer.


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## garrett (Jan 12, 2012)

Okay, I get it. Thanks though.

Maybe someone else can provide some advice.


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## mark handler (Jan 13, 2012)

garrett said:
			
		

> Maybe someone else can provide some advice.


Ask the question until someome agrees.....


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## brudgers (Jan 13, 2012)

garrett said:
			
		

> Okay, I get it. Thanks though.  Maybe someone else can provide some advice.


  I consult at reasonable rates and accept Paypal.


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## permitguy (Jan 13, 2012)

It's not particularly complicated, and I've seen it done both ways.  The wall used for fire separation does not have to be the wall used for bearing of structural members.  A continuous wall can provide fire separation, with a traditional platform framed system built along-side to accomodate the floor/ceiling members in the short span.  You may lose a bit of square footage, but you may be able to accomodate a more open floor plan with fewer beams/columns by spanning the shorter direction.


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## Paul Sweet (Jan 13, 2012)

The best (and most expensive) way to separate townhouses is with a masonry party wall with stud bearing walls each side, or with joists fire cut into the wall.  A more economical way to separate townhouses is with a gypsum area separation assembly.

http://www.usg.com/usg-area-separation-wall-system.html


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## mark handler (Jan 13, 2012)

The cheapest and easiest way for him is to put in five 2x blocks, no gyp bd.


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## AegisFPE (Jan 13, 2012)

The continuity of floor sheathing for shear is often an issue.Paul Sheedy had an article in Building Standards that showed it continuing through a single-stud cavity area separation wall, the subject figure is attached.

View attachment 518


View attachment 518


/monthly_2012_01/Sheedy-Fig13.jpg.bab6f2d64baf59d628f097e214916225.jpg


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## mark handler (Jan 13, 2012)

AegisFPE said:
			
		

> The continuity of floor sheathing for shear is often an issue.Paul Sheedy had an article in Building Standards that showed it continuing through a single-stud cavity area separation wall, the subject figure is attached.


The problem the continuity of floor sheathing,  is sound transfer.


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## Fort (Jan 14, 2012)

I only see area separation systems in high end condos,

For typical townhouse apartments a common 2x4staggered stud on 2x6 or 2x8 plate is mostly what I see.

Floor sheathing can run thru.

Structural independence not required.

Sound transfer is important to consider, but can't get too hung up on it,

since there are not good published testing results from these types of conditions.

Sure we have STCs for wall and floor assemblies, but not intersections.

Floor joists can run parallel or perpendicular to common wall.

Always best to use 5/8 type x below floor/ceiling, even if rating not required...it costs nothing, just good practice to help reduce risk.

Even if floor joists run parallel, if common wall is used as lateral then there will be perpendicular blocking at 48" o.c. that would penetrate the wall membrane anyway. And since structural independence is not required, it is just the solid blocking that protects the intersection.

Only plan check comment on garret's detail linked is to add fillers between webs of I-joists so no gap where solid blocking butts to it.


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## Paul Sweet (Jan 16, 2012)

Some jurisdictions will allow solid blocking, but I've encountered a lot more that say continuity is lost anywhere the rated gypsum board stops.  It's easy to cut the blocking to fit between wood joists, but fitting it between I-joists is a lot trickier.


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