Document Qg1gxzyzO4GMXQorQ39zaw1B7

INTERDEPARTMENTAL. COMMUNICATION TOx ALL GYPSUM DIVISION REG I ONA^. MANAGERS PROM: ^ T. R. Godfrey SUBJECT: 5/8" FIRESTOP TYPE X DATE: December 5, 1969 LOCATION: LOCATION: Portland We now have a letter interpretation from Underwriters Laboratories listing the use of 5/8" Type X Wallboard on all of our 1-hour and l^-hour rated f1oor/cei1ing assemblies. This will clear up the confusion as to whether Type X or Type XXX is required, The_ojiLy^.a.$sembHes now still reoui ring.. 5/8" Type XXX are the 2-hour ratings (UL Designs $217 and V/2~59)_ Those f1oor/cei1ing assemblies allowing Type X are: Floor and ceiling Designs UL //l 1-hour. //19 1-hour, $13 l?-hour, and the 2-hour beam constructions, UL #254 and #255. Also, of course, continue to sell Type X on all wall assemblies. This new listing will cover the use of 46 to 54 inch wide wallboard and 2 foot wide Backer Board. As our sales in volving the 2-hour floor/ceiling assemblies are small, 5/8" Type XXX board shortly will be on a special order basis only, so anticipate the requirements. TRG/mf CC: Mr. 0, E. Burch - Portland Mr. C. W. Lehnert - Tigard Lab Mr.EB.Hoi 1ingsworth - Portland Mr. T. W. Richards - Portland 7>/, 74 UfgL ydv? mJ/ A ^7 '/> i/ . .7 e . <; .U-rfV.WrI*-'1' (`t - 'f- i- > 0 * 'j ^ r.U-v { ^ ->'**'- ^ /' ty v/1. . ' f i- - : * '< ' j.'t /) i i 7- J.... t . - - '/ '^ ' ' -<' / npc n R L SGP 0025651 SGP 0025648