Door Labels

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Author Message George A. Everding, AIA, CCS, CSI Senior Member Username: geverding Post Number: 27 Registered: 11-2004 Posted on Thursday, March 31, 2005 - 10:11 am:    What was the reference standard that identified rated doors by letter designations (B-label) and when did it become obsolete in favor of hourly designations (1 1/2 hr.)? William C. Pegues, FCSI, CCS Senior Member Username: wpegues Post Number: 365 Registered: 10-2002 Posted on Thursday, March 31, 2005 - 12:22 pm:    George, I don't know where it originated, but I have seen the letter designations listed in many different other standards. It has been around for a long time, I remember it from my early days in the 70s. However, even then we were always correcting the door schedule and making the project architect's remove the letter designations and use the true hour/minute rating. Reason why? B Label had 2 designations. There was a B 1-hour and a B 1-1/2 hour label. So why use that and its resultant potential for contractor confusion and just go straight to the hourly. Even back in the 70s we were discouraging the letter designations. Nowdays, its pretty standard to not use them and see only the hour/minute designator. About the only time I ever see a letter designator used is on projects by interior designers. William Anonymous   Posted on Thursday, March 31, 2005 - 12:29 pm:    Door labels??? .... ugh, OK. How many would you like to buy? Kenneth C. Crocco Senior Member Username: kcrocco Post Number: 21 Registered: 04-2003 Posted on Tuesday, April 05, 2005 - 12:21 pm:    The designations, I believe, are from NFPA 80 Fire Doors and Fire Windows. The older designations of letters were used in previous issues of NFPA 80. The new standard lists ratings in terms of minutes: 20, 45, 60, 90, David Axt, AIA, CCS, CSI Senior Member Username: david_axt Post Number: 432 Registered: 03-2002 Posted on Thursday, April 07, 2005 - 12:59 pm:    The Steel Door Institute (SDI) used to designate doors with letters: A - 3 hour door B - 90 minute door C - 45 minute door D - Exterior 90 minute door That system was abandoned in lieu of just calling out the minute rating of the door. As you can see there is no 60 minute door designation. So basically you should not be specifying with the letter designations. David Stutzman Senior Member Username: david_stutzman Post Number: 39 Registered: 07-2002 Posted on Thursday, April 07, 2005 - 01:47 pm:    The letter designations come from NFPA 80. They designate the door location only, not the required rating. A-label doors are used in fire walls, B-label in vertical shafts, C-label in partitions, and D-label for exterior locations. You can get a 90 minute B-label and a 60 minute B-label door. So using the lettered label designations was never a complete description of the fire rating requirement. David Axt, AIA, CCS, CSI Senior Member Username: david_axt Post Number: 435 Registered: 03-2002 Posted on Monday, April 11, 2005 - 05:33 pm:    I checked with my local steel door supplier and they still use the letter nomenclature to order doors. I guess old habits die hard. John Bunzick, CCS, CCCA Senior Member Username: bunzick Post Number: 348 Registered: 03-2002 Posted on Tuesday, April 12, 2005 - 08:47 am:    Yes, and steel door suppliers still use gauge to measure thickness. Joseph Berchenko Advanced Member Username: josephberchenko Post Number: 5 Registered: 08-2003 Posted on Wednesday, April 13, 2005 - 01:09 pm:    BTW. The letter "S" should appear on smoke door labels per the IBC. Additionally, some manufacturers have proposed using letters A through J on their labels to indicate product "Category." As I understand it, these categories relate to edge condition and positive pressure testing for various door components. Category A indicates doors that do not require additional edge seals to meet positive pressure testing, usually because they have built-in intumescent seals. Category B doors require an attached edge seal to meet requirements. Other labels are for opening components other than doors: Category C is for frames; D is for door/frame assemblies; E is for hardware; F is for light kits; G for edge seals themselves; H for smoke and draft control gaskets; and J for other types of gaskets. Some manufacturers have info on their web sites about category labels, but I have not yet found a good non-proprietary source on the subject. Has anyone started seeing these category labels? Has anyone started specifying categories in their door schedules? Tom Heineman RA, FCSI, SCIP Senior Member Username: tom_heineman Post Number: 45 Registered: 06-2002 Posted on Thursday, April 14, 2005 - 09:19 am:    Joseph, Do you know what the format is for adding A and B category designations? Are these suffixed to the minute designation? Is there any delimiter: a hyphen? a space? no space? My state is just publishing its newly adopted IBC code, so I will not be able to look up this requirement for a month or two. Joseph Berchenko Senior Member Username: josephberchenko Post Number: 6 Registered: 08-2003 Posted on Thursday, April 14, 2005 - 11:33 am:    I first learned of this at a presentation by David San Paolo with the Maiman Company. They have some additional info at the Maiman web site under http://www.maiman.com/download/pdf/Maiman_Bndr_Sec_10_Pos_Pressure.pdf. This includes a tech bulletin very similar to one on the WDMA website. Neither the 2003 IBC (see 715.3.5.1) nor NFPA 80 discuss "Categories" as far as I can tell (Note, though, Appendix E of NFPA 80 answers original question about letter vs. time designation of ratings.) Not sure without further research what the format is or who originated it, but I understand both UL and Warnok Hersey have a certain format they use for their labels that now includes Categories. Perhaps someone else can enlighten us. I bring this issue up because it's possible to see "Category A" and "20 minute" on a label and be confused if you don't know that "Category" differs from "Fire Resistance Rating." This might have been what occasioned the original query for this thread. Anonymous   Posted on Monday, June 20, 2005 - 06:44 pm:    I am looking for informtion on Thermal Break Down Frame usage, is anybody advise me where actually these frames can be use.