CONCRETE BLOCK FIRE RATING

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Author Message Jerome J. Lazar, CCS, CDT, CSI, SCIP Senior Member Username: lazarcitec Post Number: 2065 Registered: 05-2003 Posted on Wednesday, October 30, 2019 - 04:56 pm:    WHERE IN A TYPICAL CONCRETE UNIT MASONRY SPEC SECTION IS THE FIRE RATING SPECIFIED? Brian Payne Senior Member Username: brian_payne Post Number: 200 Registered: 01-2014 Posted on Wednesday, October 30, 2019 - 05:00 pm:    It isn't for me. The fire rating is indicated in the drawings. Section 721/722 of the code gives prescriptive/calculated thicknesses required to meet hourly ratings. Jerome J. Lazar, CCS, CDT, CSI, SCIP Senior Member Username: lazarcitec Post Number: 2066 Registered: 05-2003 Posted on Wednesday, October 30, 2019 - 05:02 pm:    Brian, the Architect is insisting I add the fire rating to the spec section, specifically for two hour rating. Brian Payne Senior Member Username: brian_payne Post Number: 201 Registered: 01-2014 Posted on Wednesday, October 30, 2019 - 05:05 pm:    Typically, the only impact the rating has for a 2HR block wall is on the firestopping at the penetrations and any openings. Otherwise, the cmu doesn't change for a nonrated, 1 HR, or 2HR wall. 3 Hr requirements can sometimes exceed the face thickness of standard cmu block. Brian Payne Senior Member Username: brian_payne Post Number: 202 Registered: 01-2014 Posted on Wednesday, October 30, 2019 - 05:10 pm:    Fire Resistive Rating: As indicated on Drawings. Done! George A. Everding, FCSI, CCS, CCCA, AIA Senior Member Username: geverding Post Number: 904 Registered: 11-2004 Posted on Wednesday, October 30, 2019 - 05:18 pm:    Jerry- See NCMA Tek notes, particularly this one: https://ncma.org/resource/fire-resistance-ratings-of-concrete-masonry-assemblies/ This tech note refers to IBC 722 as Brian mentions. There are other Tek Notes that might be relevant to your question - you can search the NCMA Tek Notes for Fire Rating. For Example 05-08B is a good reference for how to address fire ratings on Drawing Details. Jerome J. Lazar, CCS, CDT, CSI, SCIP Senior Member Username: lazarcitec Post Number: 2067 Registered: 05-2003 Posted on Wednesday, October 30, 2019 - 05:21 pm:    Client is stubborn, they are insisting I include in spec section, but where, how? Marc Chavez Senior Member Username: mchavez Post Number: 533 Registered: 07-2002 Posted on Wednesday, October 30, 2019 - 05:22 pm:    Back to Jerome's initial question....IF you need to place it in the specs. (I also try to have this on the drawings as code officials are looking for it there) Make a performance requirement article in part 2 and place the appropriate language there... mentioning the IBC chapter and verse. then back in part one in related requirements list the fire stopping section Paul Sweet (Unregistered Guest) Unregistered guest Posted on Wednesday, October 30, 2019 - 05:10 pm:    The drawings should show where the different ratings (or unrated block) go. Part 2 of the specs should say what type of block is required for different ratings. Monsterspec is written around UL U906 and a lot of A/E's blindly require it, even though it requires a stamp on the block that increases the cost of the block. I always use the equivalent thickness method of IBC 721 722. You can get a 2 hour rating from regular block with solite or similar aggregate, and 3 or 4 hours with 75% solid block. Mark Gilligan SE, Senior Member Username: mark_gilligan Post Number: 918 Registered: 10-2007 Posted on Thursday, October 31, 2019 - 03:49 pm:    As stated the code provides prescriptive fire rating for a certain type of block construction. It does not need to be shown on the drawings. If you listed the fire rating of the block ask yourself what do you expect the contractor to do to show that he has complied? I suspect that this is really in response to UL's program where they perform a fire test on a specific manufacturers block thus allowing the manufacturer to apply a mark/label to their block. This is just your generic concrete block. There is no difference between the concrete block with the UL rating and the concrete block assembly listed in the building code. UL then uses this process to pressure concrete block manufacturers to pay UL to perform the test and allow them to place the mark on their block. I repeat there is no technical justification for requiring UL certified concrete block. It only increases the cost to the Owner. When UL performs fire tests of fire caulking in a masonry wall they then list as part of the assembly concrete block units that have their certification Since the fire caulking UL test assumes an assembly with UL certified block the caulking cannot be used on block walls that do not have the certification. This means that if the block in an existing building was manufactured before the UL program you cannot place a new hole in the existing wall. I suggest that UL is using their market power to create a monopoly for themselves. ken hercenberg Senior Member Username: khercenberg Post Number: 1252 Registered: 12-2006 Posted on Thursday, October 31, 2019 - 04:19 pm:    Hi Jerry. So as Mark noted, in order for the GC to document compliance they will need to buy UL-certified CMU which will increase the cost to the client. Perhaps the Architect would like to confirm that is the intent, to add unnecessary cost to the client. I'd ask for that in writing for sure. Marc Chavez Senior Member Username: mchavez Post Number: 534 Registered: 07-2002 Posted on Thursday, October 31, 2019 - 04:39 pm:    IMHO, No. they do not need to buy UL certified block. they need only to show the code official the product they are building with (sim to what they do with mortar and bricks) and a clip from the IBC if needed to reinforce the fact that it is allowed. No UL certification needed BECAUSE they have the building code....do we ask for UL certification for 2 hour concrete walls? no. we just measure the thickness and perhaps if forced, a mix design. Also. I have done this many times and had no problem, in the spec, on a table in the dwgs, on assys in the dwgs, never an issue. Brian E. Trimble, CDT Senior Member Username: brian_e_trimble_cdt Post Number: 115 Registered: 08-2005 Posted on Thursday, October 31, 2019 - 04:47 pm:    Agree with all the posters above. You can put the requirements for the necessary type of block (aggregate type, void percentage) in Part II of the masonry section. You can ask for certificates from the block manufacturer to show they meet what was specified. As previously mentioned - no need to get UL ratings when equivalent thickness is a code-approved procedure. John Bunzick, CCS, CCCA, LEED AP Senior Member Username: bunzick Post Number: 1795 Registered: 03-2002 Posted on Thursday, October 31, 2019 - 05:43 pm:    Also, if a partition is NOT shown to be rated, but is constructed with UL-labeled CMU, that doesn't mean it meets the code as a rated partition. Fire stopping, treatment of embedded items, etc. come into play. Ronald L. Geren, FCSI Lifetime Member, AIA, CCS, CCCA, CSC, SCIP Senior Member Username: specman Post Number: 1570 Registered: 03-2003 Posted on Thursday, October 31, 2019 - 05:48 pm:    I just specify the equivalent thickness based on the worse case aggregate condition (Calcareous or siliceous gravel). Any of the other lighter aggregates (or combination thereof) will only increase the fire resistance for the specified equivalent thickness. Ron Geren, FCSI Lifetime Member, AIA, CCS, CCCA, CSC, SCIP