Document ppkno49o5emELw2OwwmrO0jzw

WRGrr 1234 770061 IUNDERWRITERS' LABORATORIES, INC, 333 PTlNClTtN MAD wihmbok. ilunou mm PLAINTIFF'S EXHIBIT an independent 'not-for-proft organization testingfor public safety! I I J^WRG-53 5^ R4339 70HK2145 June 9, 1970 ] Zonolite Construction Products Dlv. V. R. Grace & Company 62 Whittemore Avenue Cambridge, Massachusetts 02140 Attention: Mr. Thomas P. Felt Manager, Technical Services IT JUN 1 2 1970 CAMBRIDGE Dear Mr. Felt: This is in reply to your letter dated May 20, 1970. We apologize for the delay In answering; however, we did not receive the letter until June 5* 1970. It is correct that based upon a successful fire test, the revised Mono-Kote formulation will be Listed for all existing designs presently Listed for use with Mono-Kote cementitious material except Floor and Ceiling Design Nos. 219 - 2 Hr and 257 - 2 Hr. The use of the revised Mono-Kote for these two designs when the steel floor and form units are arranged in an alternating one-to-one pattern may be approved on an individual engineering study basis. The reason for this is that cellular steel floor units have better temperature transmission properties when compared to fluted units. Therefore, a one-to-one pattern may Jeopardize the fire resistance classification of Floor and Ceiling Design No. 219 - 2 Hr. Very truly yours, RMB:eJ ROBERT M. BERHINIG Cj Project Engineer ^ Fire Protection Department 20085611