External fire plumes from mass timber compartment fires—Comparison to test methods for regulatory compliance of façades
(2023) In Fire and Materials 47(4). p.433-444- Abstract
Post-flashover fires inherently lead to external fire plumes, constituting a hazard for rapid fire spread over façades. As multi-storey mass timber buildings with internal visible timber surfaces become more common, there are concerns that such buildings would produce larger external plumes and hazards (assuming all other parameters equal). The literature reveals only indications of this, and how the actual exposure relates to different test methods for assessment is unknown. Here we utilise a series of full-scale mass timber compartment tests to quantify the exposure to the external façade. An incombustible external façade is instrumented with gauges at positions corresponding to reference data from several different assessment... (More)
Post-flashover fires inherently lead to external fire plumes, constituting a hazard for rapid fire spread over façades. As multi-storey mass timber buildings with internal visible timber surfaces become more common, there are concerns that such buildings would produce larger external plumes and hazards (assuming all other parameters equal). The literature reveals only indications of this, and how the actual exposure relates to different test methods for assessment is unknown. Here we utilise a series of full-scale mass timber compartment tests to quantify the exposure to the external façade. An incombustible external façade is instrumented with gauges at positions corresponding to reference data from several different assessment methods. The results show that there is an increase in plume duration, height, and temperatures when increasing the areas of exposed timber, but that this increase is less for normal- to large-opening compartments, than was previously seen in small-opening compartments. Also, normal variations in external wind speed have a larger influence on plume heights than the effect of doubling exposed timber surfaces. Test methods used for regulatory compliance differ significantly not only in exposure but also in pass/fail criteria. The proposed European large exposure method and the BS8414 method exhibit exposures on par with the severe end of what could be expected from mass timber compartments, whereas methods like SP Fire 105 and Lepir II produce significantly less severe plumes. However, the safety level is always a combination of exposure and assessment criteria. This data can help justify assessment criteria from a performance perspective.
(Less)
- author
- Sjöström, Johan ; Brandon, Daniel ; Temple, Alastair ; Anderson, Johan and McNamee, Robert LU
- publishing date
- 2023-06
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- BS 8414, exposure, external flaming, Façade, mass timber compartments, standard, testing
- in
- Fire and Materials
- volume
- 47
- issue
- 4
- pages
- 12 pages
- publisher
- John Wiley & Sons Inc.
- external identifiers
-
- scopus:85147449069
- ISSN
- 0308-0501
- DOI
- 10.1002/fam.3129
- language
- English
- LU publication?
- no
- additional info
- Funding Information: Brandforsk, The Swedish fire research fund and the European Commission (grant SI2.825082 - Finalisation of the European approach to assess the fire performance of façades) are greatly acknowledged for financial support. Additionally, the work could not have been performed without the funding for the mass timber compartments for which we acknowledge United States Forest Service (USFS) - United States Department of Agriculture and other contributing industry partners for material and advice (American Wood Council, Henkel, KLH, Boise Cascade, Rothoblaas, Softwood Export Council, Atelier Jones, UL). Funding Information: Brandforsk, The Swedish fire research fund and the European Commission (grant SI2.825082 ‐ Finalisation of the European approach to assess the fire performance of façades) are greatly acknowledged for financial support. Additionally, the work could not have been performed without the funding for the mass timber compartments for which we acknowledge United States Forest Service (USFS) ‐ United States Department of Agriculture and other contributing industry partners for material and advice (American Wood Council, Henkel, KLH, Boise Cascade, Rothoblaas, Softwood Export Council, Atelier Jones, UL). Publisher Copyright: © 2023 The Authors. Fire and Materials published by John Wiley & Sons Ltd.
- id
- bc071ca2-4c51-460e-b4a1-6236dae84659
- date added to LUP
- 2024-01-12 15:50:13
- date last changed
- 2024-01-15 09:44:35
@article{bc071ca2-4c51-460e-b4a1-6236dae84659,
abstract = {{<p>Post-flashover fires inherently lead to external fire plumes, constituting a hazard for rapid fire spread over façades. As multi-storey mass timber buildings with internal visible timber surfaces become more common, there are concerns that such buildings would produce larger external plumes and hazards (assuming all other parameters equal). The literature reveals only indications of this, and how the actual exposure relates to different test methods for assessment is unknown. Here we utilise a series of full-scale mass timber compartment tests to quantify the exposure to the external façade. An incombustible external façade is instrumented with gauges at positions corresponding to reference data from several different assessment methods. The results show that there is an increase in plume duration, height, and temperatures when increasing the areas of exposed timber, but that this increase is less for normal- to large-opening compartments, than was previously seen in small-opening compartments. Also, normal variations in external wind speed have a larger influence on plume heights than the effect of doubling exposed timber surfaces. Test methods used for regulatory compliance differ significantly not only in exposure but also in pass/fail criteria. The proposed European large exposure method and the BS8414 method exhibit exposures on par with the severe end of what could be expected from mass timber compartments, whereas methods like SP Fire 105 and Lepir II produce significantly less severe plumes. However, the safety level is always a combination of exposure and assessment criteria. This data can help justify assessment criteria from a performance perspective.</p>}},
author = {{Sjöström, Johan and Brandon, Daniel and Temple, Alastair and Anderson, Johan and McNamee, Robert}},
issn = {{0308-0501}},
keywords = {{BS 8414; exposure; external flaming; Façade; mass timber compartments; standard; testing}},
language = {{eng}},
number = {{4}},
pages = {{433--444}},
publisher = {{John Wiley & Sons Inc.}},
series = {{Fire and Materials}},
title = {{External fire plumes from mass timber compartment fires—Comparison to test methods for regulatory compliance of façades}},
url = {{http://dx.doi.org/10.1002/fam.3129}},
doi = {{10.1002/fam.3129}},
volume = {{47}},
year = {{2023}},
}