Document Ev9MaqgxDwYxwb1zjRJ01Nbg0

November 30> 1959 TO: All Sales Managers All Salesmen GENERAL SALES BULLEYIN CC: MESSRS. SUBJECT: PIRESTOP Malcolm Meyer .- President C. E. Berzelius - Vice President RE: Factory Mutual Insurance Companies BY: C. E. Abbey - cc The Underwriters' Laboratories is a nonprofit testing agency set up to determine the fire risk, burglary risk, or other casualty involved with various building materials, assemblies, pieces of equipment, etc. and assist insurance companies in properly evaluating the items involved. They have the support of and work with the National Board of Fire Underwriters' which is essentially a trade organization of stock Fire Insurance Companies. A group of Mutual Fire Insurance Companies specializing in fire insurance on factory construction, formed an Association of Factory Mutual Fire Insurance Companies many years ago. They have their testing facilities (the Factory Mutual Engineer ing Fivision) located in Norwood, Mass,, outside of Boston. Many times this group will accept test work performed by the Underwriters' Laboratories. At other times, they will run their own tests as they, the technical advisors of the Factory Mutual Insurance Companies, issue technical bulletins to these member companies evaluating the risk involved. Forwarded herewith is a copy of a "Loss Prevention Data" sheet, "Construction 1-36", dated July, 1959, distributed by the Factory Miutual Engineering Division. The title is "Fire Barriers Using Type X Gypsum Board". This is the general term applied to a Firestop type board under ASTM definitions. The purpose in forwarding this sheet is to show that the Factory I utual Insurance Companies are officially aware of Firestop type board and should, therefore, reflect the use of Firestop in constructions where fire resistance is necessary. Notice that it includes general constructions that have been tested with most of the competitive type mate?ials and has one or two that are limited specifically to Firestop. For instance, Bestwall is the only manufacturer of this type material to make and test a 3/9" thick Firestop board. Presently 3/9" Firestop is not being manufactured and is not available. Of great importance is the listing under Table I, "Fire Re sistance Insulated Mfetal Wall Panels". Essentially, these are multiple layers of l/2" thick Firestop type boards, faced with metal. Some of them are three, some four and some five sheets in a solid section; others have two thicknesses on each side of the construction. Many of the metal clad wall manufacturers are doing a great deal of promotion of this type construction. These walls are important In light SGP 0003187 D^C 1059 \o\ received m siwAjisysMw :?' rntmi } l' i *< ,, . i '/' * SGP 0003188 -2- GENERAL SALES BULLETIN #220 steel frame buildings and in warehouse type buildings, both new and remodeled where two and three hour separation may be required under building codes because of the areas involved or occupancy. Be sure you understand this enclosure and follow up to see that l/2" thick Pirestop Bestwall is used on these metal clad walls for erection. While some of the original tests were made with Pirestop board, Underwriters', in their standard procedure, have extended label service to any l/2" thick fire rated gypsum wallboard labeled. One instance where such a partition was used in remodeling was in an air plane hanger, requiring several carloads in one wall, 30 to ij.0 ft. high and over 3000 ft. in length. In order to have this material for ready reference, it is suggested you file both the bulletin and the enclosure in your Gypsum Products Manual directly after the Bestwall Firestop competition booklet, 59167, and directly in front of the Bestwall Hummer System "A" booklet. This is in Chapter IV, Building Materials. SGP 0003189 ttf- ``..0 r-fC iSfy \ i K4 w; ' &(/g ?/ ';k aaSrJ^ SGP 0003190 LOSS PREVENTION DATA FACTORY MUTUAL ENGINEERING DIVISION 1151 Boston-Providence Turnpike, Norwood, Mass. CONSTRUCTION 1-36 July 1959 FIRE BARRIERS USING TYPE X GYPSUM BOARD Gypsum boards having increased fire resistance are produced by most gypsum board manufacturers. De signated as Type "X" (special fire retardant), they are similar to the standard type in appearance and dimen sions but have a different composition which provides the improved fire resistance. They are used as the core of insulated metal wall panels and as sheathing for wood framed walls, partitions, and ceilings with resulting improved fire resistance ratings as indicated below. All the listed ratings were determined by tests conducted in accordance with ASTM Specification E119, the standard test procedure for determining the fire resistance of walls and ceilings. INSULATED METAL WALL PANELS Two types of insulated metal wall panels are cur rently available. Both have metal exterior facings but use different insulating materials in the core. One type which is commonly used for exterior building walls has little or no fire resistance. It utilizes a glass fiber blanket insulation as the core material and is generally 3-1/4-in. or less in overall thickness. The other type, which has fire resistance qualities, utilizes several layers of Type X gypsum board as the core material. The panels are assembled at the job site generally using 1-1/2-in. deep, 18 gauge steel facing sheets of various configurations and four 1/2-in. thicknesses of Type X board, all held in place with mechanical fasteners. They have an overall thickness of at least 5 inches. The manufacturers, typical cross sections, fire test data, and fire resistance ratings are given in Table I. SGP 0003191 1-36 Page 2 The insulated metal wall panels listed in Table I are suitable for installation at Factory Mutual insured loca tions as nonload-bearing fire barriers wherever fire severity and duration do not require a wall having a fire resistance rating greater than listed in the table. Where structural framework supporting the panels is subject to the same exposure as the panels, the framework should have equivalent fire resistance. The framework should also be capable of remaining in place when subject to forces resulting from a major collapse of structural framing due to fire on either side of the wall. TYPE X GYPSUM BOARD SHEATHING Type X gypsum board, applied as sheathing to wood stud partitions, wood-joisted ceilings, and one face of wood stud walls, provides fire resistance for the period indicated in Table H. Stud or joist spacing should not exceed 16 inches. Other wall, floor and ceiling constructions using Type X boards as components have been tested and rated. They are acceptable for their respective rat ings but are not included here because of their limited application. TYPE X GYPSUM BOARD MANUFACTURERS The following listed manufacturers, with the indi cated trade names produce Type X gypsum board. Barrett Division, Allied Chemical Corp. Fire Wall Bestwall Gypsum Co. Firestop Bestwall Blue Diamond Corp. Fire Halt Celotex Corp. Celo-Rok Fire Resistive Flintkote Co. Fire-Ex Kaiser Gypsum Co., Inc. Null-A-Fire National Gypsum Co. Fireshield Pabco Building Materials, Division of Fiberboard Paper Products Corp. Flame Curb Union Gypsum Co. Blaz Blok United States Gypsum Co. Sheet Rock Fire Code 45-60 SGP 0003192