AnsweredAssumed Answered

Interior Finish Flame Spread testing

Question asked by robertforister on Feb 11, 2019
Latest reply on Feb 16, 2019 by sourabhchowdhuri

Question pertaining to NFPA 101: Classification of interior finish materials shall be in accordance with tests made under conditions simulating actual installations.

An installation of stained tongue and groove douglas fir (3/4' nominal) installed on 5/8" gypsum wall board. In a fully sprinkled business occupancy.


AHJ has cited, asking for testing of material as installed to verify it meets the required Class C rating.  I have provided testing data showing the douglas fir meets a Class B rating.  Test data supplied by American Wood Council using ASTM E84 as the test method.  


My question is: what is the intent of  

Follow up question: For an interior finish flame spread/smoke development rating, is it typical to accept an ASTM E84 test of the material, even if it is tested without the base material, surface coating (stain), and attachment method (nails)?