Fire Safety Guidelines for Solar Roofs: Lessons from FRISSBE & ZAG

European research confirms: rooftop fires spread because of combustible roofs. AllShield makes roofs inherently safe and insurable — even with solar panels.

How European research supports AllShield’s mission for safer, insurable roofs

European research confirms what insurers and building owners already fear: rooftop fires with solar panels often escalate because the roof itself is combustible. In May 2024, the Slovenian National Building and Civil Engineering Institute (ZAG), as part of the European FRISSBE project, published its Fire Safety Guideline for Building Applied Photovoltaics (BAPV). This independent guideline highlights the risks and gives clear recommendations to prevent rooftop fire disasters.

Why this matters

Across Europe, the number of flat and sloped roofs with solar panels is growing rapidly. While PV helps reduce carbon emissions, it also brings new fire hazards. The guideline stresses three key findings:

• Rooftop fires often start with electrical failures, but spread because of flammable roofing materials.
• Existing roofs with bitumen and EPS insulation are especially vulnerable.
• Passive, non-combustible barriers beneath PV systems are crucial to limit fire spread and protect property.
  
  

AllShield solutions amid complex certifications

The FRISSBE/ZAG guideline confirms the approach AllShield has pioneered for years: making roofs inherently fire safe, regardless of PV technology or installation quality. Yet, one of the biggest challenges remains the lack of harmonized testing and approval methods across Europe.

• BarrierSheet – Independently tested by ZAG, following the 4 PV-panel setup of the NEN7250:2021 (under review)  and classified Broof(t1). A lightweight, non-combustible underlayment that prevents fire spread under roofing membranes.
• AllShield Blue – tested under the NEN 7250:2021 (under review) and FM4482 Approved as a repair coating on FM-approved roofs, enhancing existing solar-equipped roofs into fire-safe, insurable systems.

However, the patchwork of requirements across markets adds significant complexity and cost. For example: England mandates Broof(t4), continental standards often accept Broof(t1), and FM Approvals uses norms like FM 4478/4476. Recent industry updates show FM has now introduced a new, more stringent standard—FM 4478—which certifies the combined system of solar panel + mounts/racking + roofing  and insulation with metal roof.This confirms how fragmented and demanding testing can be, especially for integrated roofing and solar systems.

Towards European harmonization

The FRISSBE guideline underlines the urgent need for harmonized testing and approval methods across Europe. AllShield contributes to this development by:

• Performing independent testing at ZAG and Kiwa-BDA.
• Achieving Broof(t1) classification.
• Attaining FM Approval for AllShield Blue as a repair coating on FM-approved roofs.

Still, the lack of alignment forces manufacturers, insurers, and building owners to navigate a fragmented certification landscape—resulting in time-consuming, costly delays that hinder wider implementation of safe roofing solutions.

The bottom line

The ZAG/FRISSBE guideline demonstrates that fire-safe roofs with solar panels are achievable—but only if the roof itself is non-combustible. AllShield provides exactly that: tested, certified, mineral-based protection that makes commercial roofs safer and insurable. Simultaneously, we continue advocating for unified approval standards so these proven, fire-safe solutions can be deployed more quickly, affordably, and broadly.