Document pmdz3935KEgmLGjY5rvbq1aX7

GAF CORPORATION J___*-- r\r..j Quality Control Department So. Bound Brook, New Jersey April 30, 1971 TOt THE MEMBERS OF THE RESEARCH COMMITTEE Messrs* Carroll Roman L. C. Haack George Stepien, Jr, Dr* Ernest Long J. C. Lawrence Jean A. Berg C. L. Jewett C. I. Read John Horai W. C. Cullen Bird & Son, Inc* Certain-teed Products Corp. The Flintkote Company Johns-Manville Corporation Koppers Company Owens-Coming Fiberglas Corp. 3M Company Tilo Co., Inc. - A. A. A. GAF Corporation - Industrial Products Division N. B. S. Gentlemen! Following our last committee meeting in New York City, I wrote to Mr. Ed Davis of the Underwriters* Laboratories regarding further investigative work that the U. L. might wish to have in order to accept a higher stabilizer content in asphalt coating. Attached is a Gafax copy of the reply received from Mr, S, L* Donahue. Please be prepared to bring #ith you any data (with copies you cein give to me and others on the committee) that we can compile for the U. L. in regard to granule adhesion tests at various stabilizer contents. This data need not be at the specific concentrations mentioned by Mr. Donahue, Also, any data or suggestions as to an answer on the correlation between weatherometer data and outdoor weathering. We will place this item on the agenda for our next meeting, scheduled for May 26th and 2?th at Gaithersburg, Maryland. CG: Mr. H, H. Whittemore Chairman, ARMA Research Committee BIRD 014324 mi \ UMJLMiiflWftlTEiiS' jLABOKA'X'OKlJEifci, INC. Ti.1 I'FINUSTBN IIOAU NOHTHIIIIUOK, ILLINOIS GIIIHiZ an independent,not-for-profit organization testing for public safety Subject 774 April 15, 1971 Mr. J.. J. Kliraas Chairman, ARMA Research Committee GAF.Corpora tion 114 Cenal Road South Bound Brook, N.J. 08880 Dear Mr. Klimas: f.'i Your letter of March 18, addressed to our Mr. Davis arid, f fJ8<:; ' relative to .increased mineral, stabilizer content in asphalt . roofing products, has been referred to the writer for ,reply:.;; . *,' . When the subject wag discussed at the-November 10, 197C&S-: meeting of our Industry Advisory Conference, it was the feeling' that the data presented ,at the, time did ..not reflect the - ^ ! nr granule adhesion charaeteristicb of shingles made with coatings having a stabilizer content in. excess of 55'per cent; Since..; granule adhesion would be a. significant factory in the durability of the coating, perhaps comparative data. should'be ' . :: developed showing the' results of granule adhesion tests (using the method described in. our Standard DL 55B). on . shingles having varied percentages of stabilizer, such as 4Qi . - 55, 60, 65,'and 70. We; suggest the 70 per cent as a maximum ; : . ' since this Is the highest percentage which we recall was ori- . r`>`- \ ; ginally contemplated., Th on "fresh" samples arid on tests should be conducted bothv samples after varying periods. ; "weathering" in the weatherometer. . ftj"'.-v'.i'i..= .. -;-y:-vv; : Regarding the previous data your Committee developed,Vis there any experience or CQjnniQhly accepted way that "failure",... reflected in the data can be related to years on a roof .in i'.... various; climates? in other words, where the data indicates failure after 67, 97, l64, and 2G2 cycles, can the number of. ', cycles be expressed in; the approximate number;of actual years.-.- , a given coating will he. ejected ..to perform, both Ini warm, southern^ and western, climates as well as coldj/northern- climates?.- . -Yery truly yours, `f-s. * &!;>fr'Z-'C `y/'.V' ' - RLDicm Engineering Group Leader. : . Fire Protection Department. ' *. BIRD 014325