Cost-effective method to estimate fire protection treatment status on existing facades
Källander, Björn ; Wilkens Flecknoe-Brown, Konrad LU
and Johansson, Nils
LU
(2026)
In LUTVDG/TVBB
- Abstract
- This study presents a cost-efficient method to assess the condition of fire-retardant treatments on existing wooden façades. The method is based on measuring changes in Equilibrium Moisture Content (EMC), linked to the hygroscopic salts used in fire-retardant systems on the Swedish market. These salts increase wood moisture uptake, which can cause leaching and reduced fire performance over time.
Samples from two buildings and previous projects at Lund University were examined after periods of 11 weeks to 3 years of weather exposure. Both exposed and protected materials were analysed using controlled climate conditioning. Fire performance was evaluated with Microscale Combustion Calorimeter, Cone Calorimetry, and Single Burning... (More) - This study presents a cost-efficient method to assess the condition of fire-retardant treatments on existing wooden façades. The method is based on measuring changes in Equilibrium Moisture Content (EMC), linked to the hygroscopic salts used in fire-retardant systems on the Swedish market. These salts increase wood moisture uptake, which can cause leaching and reduced fire performance over time.
Samples from two buildings and previous projects at Lund University were examined after periods of 11 weeks to 3 years of weather exposure. Both exposed and protected materials were analysed using controlled climate conditioning. Fire performance was evaluated with Microscale Combustion Calorimeter, Cone Calorimetry, and Single Burning Item tests. Results show reduced EMC after ageing, indicating loss of fire-retardant chemicals. Pure salt-based systems showed significant reductions in EMC, while polymer-bound systems showed less EMC change. However, all systems exhibited decreased fire performance, with measurable decline already after only short periods of exposure. All samples tested according to the Single Buring Item- method, both from weather exposed and protected areas of the façade, showed FIGRA- results corresponding to Euroclass D.
Despite measurement uncertainties related to the material’s nature, correlations between EMC and fire performance were identified. The findings indicate that no general EMC threshold that covers all different systems can be established as acceptance criteria for the fire-retardant treatments, and system- specific acceptance criteria must be established through further targeted studies. (Less) - Abstract (Swedish)
- This study presents a cost-efficient method to assess the condition of fire-retardant treatments on existing wooden façades. The method is based on measuring changes in Equilibrium Moisture Content (EMC), linked to the hygroscopic salts used in fire-retardant systems on the Swedish market. These salts increase wood moisture uptake, which can cause leaching and reduced fire performance over time.
Samples from two buildings and previous projects at Lund University were examined after periods of 11 weeks to 3 years of weather exposure. Both exposed and protected materials were analysed using controlled climate conditioning. Fire performance was evaluated with Microscale Combustion Calorimeter, Cone Calorimetry, and Single Burning... (More) - This study presents a cost-efficient method to assess the condition of fire-retardant treatments on existing wooden façades. The method is based on measuring changes in Equilibrium Moisture Content (EMC), linked to the hygroscopic salts used in fire-retardant systems on the Swedish market. These salts increase wood moisture uptake, which can cause leaching and reduced fire performance over time.
Samples from two buildings and previous projects at Lund University were examined after periods of 11 weeks to 3 years of weather exposure. Both exposed and protected materials were analysed using controlled climate conditioning. Fire performance was evaluated with Microscale Combustion Calorimeter, Cone Calorimetry, and Single Burning Item tests. Results show reduced EMC after ageing, indicating loss of fire-retardant chemicals. Pure salt-based systems showed significant reductions in EMC, while polymer-bound systems showed less EMC change. However, all systems exhibited decreased fire performance, with measurable decline already after only short periods of exposure. All samples tested according to the Single Buring Item- method, both from weather exposed and protected areas of the façade, showed FIGRA- results corresponding to Euroclass D.
Despite measurement uncertainties related to the material’s nature, correlations between EMC and fire performance were identified. The findings indicate that no general EMC threshold that covers all different systems can be established as acceptance criteria for the fire-retardant treatments, and system- specific acceptance criteria must be established through further targeted studies. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/9105599c-106f-4826-9148-4f3f34fde4ae
- author
- Källander, Björn
; Wilkens Flecknoe-Brown, Konrad
LU
and Johansson, Nils
LU
- organization
- publishing date
- 2026
- type
- Book/Report
- publication status
- published
- subject
- in
- LUTVDG/TVBB
- issue
- 3280
- pages
- 35 pages
- publisher
- Lund University
- project
- Cost-effective method to estimate fire protection treatment status on existing facades
- language
- English
- LU publication?
- yes
- id
- 9105599c-106f-4826-9148-4f3f34fde4ae
- alternative location
- https://www.brandforsk.se/wp-content/uploads/2025/05/Brandforsk_protection-treatment-status-on-existing-facades_Report.pdf
- date added to LUP
- 2026-07-05 08:20:13
- date last changed
- 2026-07-07 11:47:26
@techreport{9105599c-106f-4826-9148-4f3f34fde4ae,
abstract = {{This study presents a cost-efficient method to assess the condition of fire-retardant treatments on existing wooden façades. The method is based on measuring changes in Equilibrium Moisture Content (EMC), linked to the hygroscopic salts used in fire-retardant systems on the Swedish market. These salts increase wood moisture uptake, which can cause leaching and reduced fire performance over time. <br/><br/>Samples from two buildings and previous projects at Lund University were examined after periods of 11 weeks to 3 years of weather exposure. Both exposed and protected materials were analysed using controlled climate conditioning. Fire performance was evaluated with Microscale Combustion Calorimeter, Cone Calorimetry, and Single Burning Item tests. Results show reduced EMC after ageing, indicating loss of fire-retardant chemicals. Pure salt-based systems showed significant reductions in EMC, while polymer-bound systems showed less EMC change. However, all systems exhibited decreased fire performance, with measurable decline already after only short periods of exposure. All samples tested according to the Single Buring Item- method, both from weather exposed and protected areas of the façade, showed FIGRA- results corresponding to Euroclass D. <br/><br/>Despite measurement uncertainties related to the material’s nature, correlations between EMC and fire performance were identified. The findings indicate that no general EMC threshold that covers all different systems can be established as acceptance criteria for the fire-retardant treatments, and system- specific acceptance criteria must be established through further targeted studies.}},
author = {{Källander, Björn and Wilkens Flecknoe-Brown, Konrad and Johansson, Nils}},
institution = {{Lund University}},
language = {{eng}},
number = {{3280}},
series = {{LUTVDG/TVBB}},
title = {{Cost-effective method to estimate fire protection treatment status on existing facades}},
url = {{https://www.brandforsk.se/wp-content/uploads/2025/05/Brandforsk_protection-treatment-status-on-existing-facades_Report.pdf}},
year = {{2026}},
}