Madrid Pioneers Fire-Resistant Building Coating to Prevent Future Tragedies
Madrid, April 15 – In response to recent catastrophic building fires in Spain, a team of researchers in Madrid has developed an innovative fire-resistant coating for building facades. This experimental material, based on silicon dioxide, promises to significantly enhance urban safety by cooling building surfaces by more than 7°C and reducing fire intensity by nearly 48%.
The initiative stems from a series of high-profile incidents, including a devastating fire in Valencia’s Campanar neighborhood just over two years ago. That blaze, which quickly engulfed two residential towers, resulted in ten fatalities and left 138 families homeless. Investigations revealed that the fire spread rapidly due to the building’s facade, which was coated with highly flammable polyethylene.
Lessons from Past Disasters: Valencia, Cartagena, and Madrid
The Valencia tragedy prompted critical questions about the safety of building materials. A similar incident occurred in Cartagena in November of the previous year, where a fire at Santa Lucía Hospital’s Block 5 also ravaged its facade, constructed with the same polyethylene-filled aluminum composite panels. Fortunately, no lives were lost in Cartagena.
Madrid itself experienced a significant fire in August 2020 at Torre Ámbar, a 20-story building on Dulce Chacón Street in Hortaleza district. The fire, which started on the roof, rapidly spread down the facade due to combustible materials. Ricardo Jiménez, head of the Madrid Fire Department, described the spread as “very spectacular.” These events underscored the urgent need for improved fire safety in construction materials.
Revolutionary Coating Developed by Imdea Materials Institute
The growing concern for fire safety has driven researchers at the Imdea Materials Institute in Madrid, led by Dr. Wei Cai and in collaboration with the Hong Kong Polytechnic University, to develop this advanced structural coating. Dr. De-Yi Wang, principal investigator and head of the High-Performance Polymers and Flame Retardants research group at Imdea Materials Institute, explained that the material’s unique properties are due to the microstructural engineering of silicon dioxide (SiO₂) particles.
These particles, commonly found in sand and glass, are designed with a dendritic, or “tree-like,” structure. This intricate design significantly enhances their thermal performance by increasing the number of surfaces and interfaces. As a result, the coating can disperse solar light in multiple directions, achieving a solar reflectivity of 95.5%-meaning it reflects almost all incoming sunlight. It also effectively emits accumulated heat as infrared radiation, with an emissivity of 94.5%.
Dual Functionality: Cooling and Fire Retardance
This dual functionality allows the coating to effectively reflect solar radiation and emit absorbed heat, thereby lowering its own temperature and limiting heat transfer to the building’s interior. The study indicates that the new coating maintains a temperature 2°C lower than conventional polyurethane coatings during the day and can even be up to 7.3°C cooler than the surrounding air temperature. This means it not only experiences less heat gain but can also achieve temperatures below ambient conditions due to its reflective and emissive properties.
In the event of a fire, the silicon dioxide particles increase the material’s viscosity, making it thicker and more stable. This prevents it from flowing or degrading easily and traps combustible gases that would otherwise fuel the flames. Dr. Wang further noted that these particles promote the formation of a stable protective barrier on the coating’s surface, which limits the transfer of heat and oxygen-both crucial for sustaining combustion. Consequently, fires develop more slowly, releasing less energy, and reducing the maximum heat release rate by approximately 48%. This significantly decreases the overall intensity of the fire.
Challenges and Future Outlook
Despite its promising features, the development faces technical challenges, primarily the scalability of manufacturing dendritic silicon dioxide particles and formulating the coating for industrial-scale production. Dr. Wang emphasized that addressing these issues will require further research, optimization, and investment.
Another limitation is the relatively thin application of the coating, which may reduce its effectiveness in prolonged or high-intensity fires. While the protective effect might not endure for extended periods in such scenarios, Dr. Wang clarified that the coating still plays a vital role in the initial stages of a fire. It can significantly reduce heat release, slow flame growth, and delay propagation, providing crucial time for evacuation and minimizing damage. Due to these ongoing challenges, there is no immediate timeline for widespread implementation.
Regulatory Changes and Unanswered Questions
The use of highly flammable materials in building facades has been a long-standing concern. As early as 2008, the Eduardo Torroja Institute of Construction Sciences (IETcc), part of the CSIC, advised against using aluminum composite panels with polyethylene cores due to their poor fire performance. Despite these warnings, such materials continued to be installed in Spain until 2019. Current regulations now require ventilated facades to be compartmentalized to prevent the “chimney effect” of fire spread, making the use of polyethylene-core sheets uncommon.
Alarmingly, two years after the Campanar fire (which occurred on February 22, 2024), Spain still lacks a comprehensive census of buildings with facades similar to the ill-fated residential complex. The Campanar building was constructed under a 1996 regulation, which was more lenient regarding flammable materials than the Technical Building Code approved a decade later. This lack of data highlights a persistent gap in addressing potential fire risks in existing structures.
The new fire-resistant coating developed in Madrid represents a significant step forward in building safety and could play a crucial role in preventing future tragedies, though further development is needed for widespread adoption.
Source: https://www.abc.es/espana/madrid/nueva-piel-edificios-disena-madrid-incendios-futuro-20260410042116-nt.html
