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HomeMy WebLinkAboutProposed Floor-Ceiling Construction - BLD Letters / Memos - 8/17/1977 Pill o 7 A 5u NoT N DEPARTMENT OF PLANNING Y 9 5593 P.O. BOX zLzn186xxFz&xx-mEsKEz SHELTON, WASHINGTON 98584 TELEPHONE 426-X2!KX August 17, 1977 International Conference of Building Officials 5360 South Workman Mill Road Whittier, California, 90601 Attention: Research Department Mr. J. Robert Nelson, P. E. Associate Research Engineer Dear Mr. Nelson: This letter will confirm our recent conversation regarding one- hour fire resistive floor-ceiling assemblies. The question to be answered involves the use of trus-joist TJL, in a three story R-1/B-2 mixed occupancy of type Vlhr. construction, for floor/ceiling joists. I.C.B.O. Research Committee Recommendation, Report No. PFC-1694 (March 1976) (H) Para. 3 refers to Table 43-C of the code for one-hour fire resistive floor-ceiling construction. The designer wishes to use the trus-joist TJL with one layer of 1/2" type "X" G.W.B. for finish ceiling, with 3/4 inch butt end plywood sheathing overlaid with 1 1/4" thick concrete for the floor above. Question: Is this an acceptable alternate for one hour fire resistive floor/ceiling construction for the standard double wood floor construction as outlined in Table 43-C and footnotes 13 (A) and (B) , using the trus-joist TJL in lieu of solid joists. A prompt reply would be appreciated, this problem arose in the advanced design stages of the project. Sincerely, fVic or D. Paolino, Deputy Fire Marshal VDP/b c MEMORANDUM August 17, 1977 Re: Alderbrook Inn Proposed Floor-Ceiling Construction A preliminary review of the building plans indicated that trus- joist TJL would be used for floor-ceiling joists. It was our opinion that the manner in which the finished ceiling and flooring above is designed does not meet with the requirements for one hour fire resistive construction as detailed in either Table 43-C or Committee Report PFC 1694. Attached you will find our letter to I.C.B.O, and other principle parties with supporting data, which was preceeded by a telephone call to I.C.B.O. Research Analyst, Bob Nelson. In speaking with Mr. Nelson it appears that we are correct in not accepting trus-joist TJL floor ceiling construction as designed for a 1 hr. fire resistive floor- ceiling assembly. Documentation of this interpretation is forth coming from I.C.B.O. and will be recorded for the file.