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Title: Relative humidity versus moisture content relationship for several commercial wood species and its potential effect on flame spread

Source: Fire and Materials. 43(4): 365-372.

Author(s)Hasburgh, Laura E.; Craft, Steven T.; Van Zeeland, Ineke ; Zelinka, Samuel L.

Publication Year: 2019  View PDF »

Category: Journal Articles
Associated Research Project(s):   FPL-4716-2A

Abstract: Recently, measured flame spread indices on commercial wood species tested per ASTM E84 were found to be lower than previously published data. One reason for this may be that the hygrothermal conditioning of the red oak calibrant required by the test standards for measuring flame spread was changed between 1973 and 1981. This paper examines how much variability there is in the moisture content of commercially important wood species at 50% relative humidity by collecting water vapor sorption isotherms. Additionally, the effect of moisture content on the flame spread was evaluated after conducting 14 tests with eastern white pine in accordance with CAN/ULC‐S102 and four in accordance with ASTM E84 at four commercial test laboratories. For the sorption isotherms, it was found that the moisture contents at 50% relative humidity ranged from 6.8% to 11.4% moisture content and depended on the species and whether the specimens had been conditioned in absorption or desorption. The flame spread indices, as measured as different laboratories, also varied from 37% at 10.4% reported moisture content to 200% at 6.5% reported moisture content. The findings suggest that the wood moisture content and conditioning requirements of the standards are important test variables that affect the flame spread results.

Keywords: Flame spread; moisture content; sorption isotherm; wood

Publication Review Process: Formally Refereed

File size: 1,024 kb(s)

Date posted: 05/03/2019

This publication is also viewable on Treesearch:  view
RITS Product ID: 94015
Current FPL Scientist associated with this product
Zelinka, Samuel L.
Materials Research Engineer

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