Indupark Center Dortmund – Double BarrierSheet build-up enables PV installation

At the Indupark Center in Dortmund, KM Dachbau has started the refurbishment of a 28,000 m² commercial roof. Due to German fire safety regulations, the AllShield BarrierSheet is applied both below and above the insulation layer — a double configuration that ensures full fire compartmentalization across the entire roof surface.

In total, 56,000 m² of BarrierSheet will be installed over the coming weeks. This is the first AllShield refurbishment project in Germany, marking an important milestone for the application of non-combustible cover boards in the country’s commercial roofing sector.

New roof build-up

The existing mineral wool insulation has been replaced with a BarrierSheet + PIR + BarrierSheet + PVC build-up. This configuration reduces the total roof weight by 14 kg/m², freeing up structural capacity for a new photovoltaic (PV) system to be installed on top.

The system combines:

• PVC waterproofing membrane

• Two layers of AllShield BarrierSheet (3.0 kg/m² each)

• PIR insulation core

This double-layer concept meets the German requirements under DIN 18234 and VdS 3145 for PV-ready roofs, ensuring that all insulation and mounting components remain fully protected against flame spread.

Refurbishment insight

During the original construction of German commercial roofs, bitumen is often applied directly onto the steel deck, without a plastic vapour barrier. This allows roofers to reapply a hot-on-hot bitumen layer immediately after removing old insulation, keeping the roof watertight while the building below remains operational.

In this refurbishment, that same approach made it possible for KM Dachbau to replace the old mineral wool safely and efficiently while maintaining continuous weather protection.

The solution with BarrierSheets enables us to reduce the weight of the roof so we can add PV!