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707.5.1 Supporting Construction - protected how?

N

nealderidder

Sawhorse
Joined
Dec 7, 2010
Messages
420
Location
Sacramento, CA
2009 IBC 707.5.1 calls for protection of construction supporting Fire Barriers. Is supporting construction; beams, joists, walls, and etc. (specifically floor joists/beams in my situation) "protected" if it is enclosed within a rated floor/ceiling assembly?

Same question for columns supporting those beams. If they are within a rated wall assembly are they "protected"?

I'm wondering if there is a scenario where structural members have to be protected (i.e. spray on fire protection) even though they are within a rated assembly. The argument being that fire really only has to get through half of the assembly to get to the structural member...

Thanks,

Neal
 
Beams and columns that support more than two stories or one story and a roof can not just be inside a rated wall and be considered rated. They must be protected individually.
 
If you have a 1-hour rated fire barrier wall it must be supported by the same hourly rated construction. A 1-hour rated floor/ceiling assembly will do that. The common mistake is in 4-story buildings that do not require protected construction until you have to support the rated EXIT shafts and other rated shafts. Due to the story height you now have a 2-hour rated requirement for supporting shaft walls. You have to choose which type of protection you are to use for supporting the shafts; a 2-hour floor/ceiling assembly or 2-hour rated protection for the beams.

With any type of protection you have to be complete to get the UL rating. With beams and columns that means full enclosure with fireproofing or using sheetrock. The Code Commentary illustrates several examples for column protection; all the way up to include the connection attachments to the beam.

Putting a column in a rated wall does not fully protect the column. The column has to be fully wrapped or enclosed on all sides per its UL listing and the walls butt into the columns rated encasement.
 
714.2.1 Individual protection. Columns, girders, trusses, beams, lintels or other structural members that are required to have a fire-resistance rating and that support more than two floors or one floor and roof, or support a load-bearing wall or a nonload-bearing wall more than two stories high, shall be individually protected on all sides for the full length with materials having the required fire-resistance rating. Other structural members required to have a fire-resistance rating shall be protected by individual encasement, by a membrane or ceiling protection as specified in Section 711, or by a combination of both. Columns shall also comply with Section 714.2.2.

Is this what you are looking for.
 
706.5 Continuity. Fire barriers shall extend from the top of the floor/ceiling assembly below to the underside of the floor or roof slab or deck above and shall be securely attached thereto. Such fire barriers shall be continuous through concealed spaces, such as the space above a suspended ceiling. The supporting construction for fire barrier walls shall be protected to afford the required fire-resistance rating of the fire barrier supported, except for 1-hour fire-resistance-rated incidental use area separations as required by Table 508.2 in buildings of Type IIB, IIIB and VB construction. Hollow vertical spaces within a fire barrier shall be fireblocked in accordance with Section 717.2 at every floor level.
 
Specifics

This is all very helpful! now I'm going to get specific... This is a three story type V-B building (Multi-family). The Fire Barriers are required for an occupancy separation (A3/R2). The trick is that the A3 space is two story (some of the 2fl is open to below) and the 2nd floor portion doesn't nicely stack over the 1fl portion (that would be too easy).

I've attached a building section. The space labeled "Activity" is A3 and is overhanging the R2 space labeled "Foyer" (hopefully the image isn't too small).If you can read it the keynote "14" is pointing out the boundaries of the occupancy separation.

So... the wall of the Activity room sits on the second floor assembly. I get that I need to provide protection for those floor joists and the beams/columns that support them. The second floor assembly is supporting one floor and a roof? If I’m correct it sounds like I might be in the “other structural members” (per Examiner’s post) and can provide protection for those structural members via “membrane or ceiling protection”?
 
The test are different. This is from the Gypsum Manual

l

Wall and partition are required to stop flame or hot gases capable of igniting cotton waste. The average temperature of the unexposed surface is not permitted to increase more than 250 degree Fahrenheit above ambient nor is any thermocouple permitted to rise more than 325 degrees Fahrenheit above ambient.

Columns are tested under a temperature limit criteria. The temperature of the steel is measured by not less than 4 thermocouples at each of 4 levels. A test is successful when the average temperature at any level does not exceed 1000 F and no individual thermocouple exceeds 1200 F within the prescribed time period
 
generally rated ceiling/floor assemblies are ok (including ceiling dampers). Designers should know this.
 
Designers should know this? I think everyone who has replied disagrees... Sounds like the test is "more than two floors or one floor and roof" if the structural member in question is supporting more than that individual encasement is required and a rated ceiling/floor assembly won't cut it.
 
Can I make a potentially insensetive comment.

It appears someone read the code and then tried to find the most complex and expensive way possible to achieve its goals.

and to furthur make every worker on the job seek weeks of traing to install every possible penetration membrane or through penetration possible

and potentially have to invent som new ones.

First the design starts by wasting the better part of more expensive 10 foot wall framing stock by making walls 9 foot something and a half

Use the 10 foot studs - double shoe and double plate for 10 foot 6 and save the saw blades.

Build your rated walls and floor ceiling assemblies and soffit all the darn ductwork and mechanical systems below it within the rated space

and add an UNRATED CEILING of whatever materil you want to conceal those systems.

What have you accomplished is reducing the number of RATED PENETRATIONs to only those necessary to get from floor to floor

cause every darn penetration the other way needs a protected assembly, fixture, or enclosure, and if complex enough a rated access panel to reset or inspect.

Build the rated box the play inside it Ever so much easier to construct and to renovate

To simplify the rated structure necessary think (CONTINUOUS LOAD PATH) and then apply the theory that if on piece is required to be RATED / Protected follow it to mother earth and any peice that assists it is also Rated
 
Architect1281 said:
Can I make a potentially insensetive comment. It appears someone read the code and then tried to find the most complex and expensive way possible to achieve its goals.

and to furthur make every worker on the job seek weeks of traing to install every possible penetration membrane or through penetration possible

and potentially have to invent som new ones.

First the design starts by wasting the better part of more expensive 10 foot wall framing stock by making walls 9 foot something and a half

Use the 10 foot studs - double shoe and double plate for 10 foot 6 and save the saw blades.

Build your rated walls and floor ceiling assemblies and soffit all the darn ductwork and mechanical systems below it within the rated space

and add an UNRATED CEILING of whatever materil you want to conceal those systems.

What have you accomplished is reducing the number of RATED PENETRATIONs to only those necessary to get from floor to floor

cause every darn penetration the other way needs a protected assembly, fixture, or enclosure, and if complex enough a rated access panel to reset or inspect.

Build the rated box the play inside it Ever so much easier to construct and to renovate

To simplify the rated structure necessary think (CONTINUOUS LOAD PATH) and then apply the theory that if on piece is required to be RATED / Protected follow it to mother earth and any peice that assists it is also Rated
Click to expand...
I may have misunderstood your comment as well as not being able to read the dimensions of the .jpg but it looks to me that the design uses standard pre-cut stud lengths. Using 10 ft studs may enable the need for fewer penetrations but won't it raise the floor to floor height and increase the number of stair risers? How will that impact the floor plan?
 
Architect1281 explanation makes sense - paraphased it means- if you can build the construction (for the load path) without the interior non-rated construction ---- nd have the load path fire rated or in a rated assembly, you probabely have met or exceeds the code requirements. The second part of the discussion would be to install the ductwork in false soffits below the rated assemblies to limit the number of penetrations (especially ceiling radiation dampers)
 
Related but different.

A Local (Municipal Official) correctly called a plan defficency on a wood frame rated stair shaft for incorrect continuity; both horizontal perpendicular wall penetration (unrated and unjustified penetration into shaft)

as well as floor assembly penetration into shaft (unrated unjustified un listed through and through penetration of landing) and back out the other side. (Oyes plans by RDP) He explaind and defined issues and being a really nice guy approved "AS NOTED" with explanation and conversation with RDP to issue SK corrective documents. Well done except framer never got the documents and constructed per plan. Inspector notes nonconformance as area is being framed refers to corrective measures, framer keeps framing per plan (bad plan). Stiil being really nice guy contacts RDP who also has required supervision. RDP Proposes non compliant alternate full of red expansive goo! Inspector documents a NO! RDP calls me at state to complain of being picked on by unreasonable Loacal Official. COnstruction marches on.. Need CO soon? Parties Appeal officials decision to local Board who says - sorry we don't waive construction errors, Parties appeal to State Appeal Board - and yesterday the State Board (my Bosses) said We don't fix construction mistakes. Compliance is the Alternative.

So as a RDP and a CBO I see far too much mis-application mis-understading by RDP's and Contractors of issues like Continuity and fire asembly rated construction. As a RDP when preparing construction documents I use only approved listed assemblies to for the continuous structure and then place the occupancies inside and up to but not through -

"With Eyes WIDE Open"

and better yet

"WITH CODE BOOK WIDE OPEN"

If as a designer you start placing objects, structure, uses, appliances, systems, into around and through listed assemblies - START OVER

When as a plan reviewer you need a GPS to track the path of a listed assembly - pull out the highlighters and send it back.

In an existing building renovation installation addition (maybe its hard to track) but on a clean sheet of paper its just unacceptable

PMARK if you need an extra step mid landing is always acceptable
 
Architect1281 said:
Related but different.A Local (Municipal Official) correctly called a plan defficency on a wood frame rated stair shaft for incorrect continuity; both horizontal perpendicular wall penetration (unrated and unjustified penetration into shaft)

as well as floor assembly penetration into shaft (unrated unjustified un listed through and through penetration of landing) and back out the other side. (Oyes plans by RDP) He explaind and defined issues and being a really nice guy approved "AS NOTED" with explanation and conversation with RDP to issue SK corrective documents. Well done except framer never got the documents and constructed per plan. Inspector notes nonconformance as area is being framed refers to corrective measures, framer keeps framing per plan (bad plan). Stiil being really nice guy contacts RDP who also has required supervision. RDP Proposes non compliant alternate full of red expansive goo! Inspector documents a NO! RDP calls me at state to complain of being picked on by unreasonable Loacal Official. COnstruction marches on.. Need CO soon? Parties Appeal officials decision to local Board who says - sorry we don't waive construction errors, Parties appeal to State Appeal Board - and yesterday the State Board (my Bosses) said We don't fix construction mistakes. Compliance is the Alternative.

So as a RDP and a CBO I see far too much mis-application mis-understading by RDP's and Contractors of issues like Continuity and fire asembly rated construction. As a RDP when preparing construction documents I use only approved listed assemblies to for the continuous structure and then place the occupancies inside and up to but not through -

"With Eyes WIDE Open"

and better yet

"WITH CODE BOOK WIDE OPEN"

If as a designer you start placing objects, structure, uses, appliances, systems, into around and through listed assemblies - START OVER

When as a plan reviewer you need a GPS to track the path of a listed assembly - pull out the highlighters and send it back.

In an existing building renovation installation addition (maybe its hard to track) but on a clean sheet of paper its just unacceptable

PMARK if you need an extra step mid landing is always acceptable
Click to expand...
:agree happens quite a bit...no good deed goes unpunished. Do you get extra LEED credit for screwups?
 
within the rated construction (which includes a rated ceiling) is protected. The designer can cost the developer as much as he wants to; spray on fireproofing doesn't play well with wood construction, since it's usually concrete based.. unless you you PT throughout.. etc... etc.
 
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