What does the suffix t1, t2, t3 or t4 mean?
The test methods in CEN/TS 1187 use different exposures. Put simply, t1 works with burning brands, t2 with burning brands and wind, t3 additionally with radiation; t4 uses its own two-stage method with corresponding external exposures. The full conditions and assessment criteria are set out in the respective method. [1]
The digits are not an ascending quality grade. A result under t1 therefore does not automatically imply a result under t3 or t4. In an enquiry, classification and bracketed suffix always belong together.
Which layers does the classification cover?
The classification report names the tested roof build-up and its field of application. Important are roof membrane, thickness, insulation, supporting layer, fixing, pitch and any additional layers. Certain changes may fall within the described range, others need their own assessment.
A specific example is Efectis 2025-R000982: the construction listed there contains a PVC membrane, BarrierSheet above the PIR insulation and a further BarrierSheet layer below the insulation, plus other layers. This result describes a build-up, not an individual board that can be combined at will. [2]
What does a PV system change?
A module above the roof membrane can direct thermal radiation back to the roof surface and change the airflow space. Distance to the membrane, module tilt and orientation influence fire development. A test without this geometry therefore does not answer every question about a fire beneath PV. [3]
This does not devalue the roof classification. It answers a clearly defined question. Additional studies and suitable design answer the question of interaction with the PV system.
Why a material class does not replace the roof test
An A1 board can be part of a roof build-up with combustible insulation and organic waterproofing. Its low own fire contribution is useful. For the overall build-up, however, joints, temperature beneath the board and possible spread paths are also of interest.
A thin layer can limit flame contact while heat reaches the insulation below. This distinction is explained in the comparison of mineral composite boards using published tests.
How to request the right evidence
Do not just send "We need BROOF", but your roof section with material names, thicknesses, fixing and PV layout. Ask which test method is relevant and which parts of the planned build-up are covered by the report.
For Germany, the Netherlands and other markets, different national requirements and project specifications may apply. Selection is therefore coordinated with the responsible specialist designer. Someone else's project or another language version of a manufacturer's page is not an automatic basis for transfer.
Do not request evidence using only the word BROOF. Specify t1, t2, t3 or t4, the complete roof build-up and the proposed PV geometry.