Understanding Fire Resistance
Fire safety in construction goes beyond following standards—it's about understanding how buildings behave under extreme conditions. True fire resistance means maintaining structural integrity under intense heat, preventing flame spread, limiting toxic smoke, and buying precious time for safe evacuation.
When engineers specify an "R60" rating for a steel beam, it must withstand a standard fire scenario for at least 60 minutes. However, fire resistance involves many aspects—not only structural strength during fire but also the material's behavior, such as whether it emits harmful gases or participates actively in fueling the fire. Toxic smoke and gases often pose serious risks within just a few minutes, making structural integrity only one piece of the safety puzzle.
From testing to innovation
Every construction material has specific fire properties. Steel can lose half its capacity at around 600°C, often requiring additional fireproofing. Concrete offers natural heat resistance, while solid timber can perform predictably in fires, charring on the outside while maintaining core strength.
This understanding has driven companies like Peikko to evolve their approach over three decades, ever since developing DELTABEAM® in the 1990s.
"Initially, we approached this through calculations," explains Raimo Lehtinen, Business Director at Peikko. "Then, we demonstrated with simple load tests that the beam could carry fire loads, even without its lower flange. Since then, DELTABEAM® has successfully passed dozens of tests worldwide without a single failure."
Fire safety requirements have evolved significantly. Products once exempt from fire protection now explicitly incorporate fire resistance from the design stage. Peikko's PETRA® connector exemplifies this evolution, transforming from a standard component to one featuring integrated fire-reinforcement bars, achieving R120 ratings.
"When a new product is being designed and developed, fire resistance is integrated from the outset," notes Lehtinen. “Besides calculations based on fire safety standards, our products often undergo rigorous testing under standard fire conditions.”
Design and future challenges
Advanced computer modeling now allows engineers to virtually test fire behavior in buildings before construction. These digital simulations reveal potential problems and optimize designs in ways previously impossible.
Thoughtful design significantly enhances building fire safety. Proper exits, fire-resistant barriers, automatic suppression systems, and effective compartmentalization can dramatically reduce fire spread. Even a strong structure isn't necessarily safe if evacuation routes and smoke management aren't adequately designed. Ultimately, fire safety is about intelligent risk management through careful material selection, thoughtful structural design, and effective coordination across disciplines.
As Lehtinen concludes, "Our testing isn't about boasting, but about ensuring safety. We want to deliver practical solutions that can be trusted, even when the unexpected happens."
Learn more about Peikko’s work on fire safety.
Product highlight: PETRA® Slab Hanger
Supporting hollow-core slabs with enhanced fire resistance you can rely on.
- R120 fire rating: Now offers up to R120 resistance (previously R60) without external fire protection.
- Integrated safety: Fire resistance built in — no extra wraps, coatings, or temporary supports needed.
- Continuous performance: Same strength and load-bearing capacity during a fire event.
- Flexible design: Available in multiple models (Standard, Strong, Special, Green), to suit spans, loads, and environmental goals.
This article was originally published in Peikko’s customer magazine Connections 2026.