Standard EN 13501-5 is used across Europe to classify roof coverings with regard to their performance when exposed to external fire. The classification is based on tests conducted according to CEN/TS 1187, which defines four test methods (t1–t4) to represent different external fire exposure conditions. Test method selection is determined by national building regulations, which specify which variant must be used for approval in each country and application.
If you wish to have your company’s roof covering tested and classified according to EN 13501-5, do not hesitate to contact our experts via the form below.
Table of contents
Test methods and method selection under EN 13501-5
EN 13501-5 classification is based on results from the following tests described in the CEN/TS 1187 standard:
Test 1 (t1): exposure to burning brands
Test 2 (t2): exposure to burning brands and wind
Test 3 (t3): exposure to burning brands, wind, and supplementary radiant heat
Test 4 (t4): two-stage test, where the material is first exposed to burning brands alone, then to all three exposure sources combined
The final classification given to the roof covering always states the test method in parentheses after the main class (e.g., BROOF(t2)), making method selection crucial for obtaining the correct classification.
National building regulations in the country where the material is brought to market dictate which method should be selected. The following are examples of EN 13501-5 classification requirements in selected European countries:
In the UK and Ireland, Test 4 is used and BROOF(t4) rating typically required when roof coverings are installed in buildings where external fire spread is a considerable risk.1
In France, Test 3 is used to classify roof coverings. BROOF(t3) classification is required for roofs installed in high-rise buildings.2
In the Nordic countries, Swedish, Finnish, Norwegian, and Danish building regulations require Test 2 to be applied. BROOF(t2) classification is typically required, apart from certain low-risk applications.3
In Belgium and Germany, roof coverings are classified based on results from Test 1, with BROOF(t1) rating required in most cases.4
Test specimen and parameter selection
Each of the four methods specified in EN 13501-5 and CEN/TS 1187 defines specific test conditions, including roof pitch, deck or substrate type, and the number of specimens. These parameters are summarized in Table 1.
Table 1: Test parameters for EN 13501-5 classification of roof coverings
Test method | Supporting deck/substrate* | Roof pitch | Number of specimens |
Test 1 (t1) | Standard deck (wood particle board, calcium silicate board, or trapezoidal steel deck), no continuous deck, or the actual intended deck. | 15° (intended pitch < 20°), 45° (intended pitch ≥ 20°), or the actual intended pitch** | 4 |
Test 2 (t2) | Standard substrate (wood particle board, expanded polystyrene (EPS), fiber-reinforced calcium silicate board, or mineral wool) or the actual intended substrate. | 30° | 6 (3 at 2 m/s wind speed and 3 at 4 m/s wind speed) |
Test 3 (t3) | Same options as in Test 1. | 5° (intended pitch < 10°), 30° (intended pitch ≥ 10° and ≤ 70°), or the actual intended pitch** | 2 |
Test 4 (t4) | Complete roof structure representative of the actual intended application. | 0° (intended pitch ≤ 10°), 45° (all other pitches), or the actual intended pitch** | 4 (1 in the preliminary and 3 in the main test) |
* The deck or substrate is selected based on the intended application. Results obtained with standard substrates are valid for similar roof designs, but tests conducted with the actual deck or substrate are only valid for the exact same construction (including material composition, dimensions, thickness, etc.).
** If the actual intended pitch is used, the results are only valid for that exact pitch.
Classification criteria for BROOF ratings
Unrestricted use of roof coverings in Europe typically requires a BROOF rating, with lower classifications only allowed in low-risk environments, such as single-family homes located a fair distance away from other buildings. To achieve the highest possible rating in accordance with each of the test methods specified in EN 13501-5, the criteria listed in Table 2 must be met.
Table 2: External fire exposure performance criteria for BROOF classes under EN 13501-5
Class | Performance criteria |
BROOF(t1) | External and internal fire spread upwards < 0.7 m and downwards < 0.6 m Maximum burned length (external & internal) < 0.8 m No falling droplets or debris, no burning particles penetrating the sample No single through opening > 25 mm2 & sum of all through openings < 4,500 mm2 No internal glowing combustion or lateral flame spread over the edge of the measurement zone Max. radius of fire spread on horizontal roofs (external & internal) < 0.2 m |
BROOF(t2) | Mean damaged length of roof covering and substrate < 0.55 m Max. damaged length of roof covering and substrate < 0.8 m. |
BROOF(t3) | External fire spread time (TE) ≥ 30 min Time to fire penetration (TP) ≥ 30 min |
BROOF(t4) | No penetration of the roof system within 1 h in the main test Burning time < 5 min and flame spread < 0.38 m after withdrawal of the test flame in the preliminary test |
BROOF classification of green roofs
The multi-layer structure, thickness, and high moisture content of soil and vegetation can complicate external fire exposure testing of green roofs according to EN 13501-5, as the test methods were not developed for such constructions. In some countries, it may be possible to get around this issue by only testing the roof covering below the growing medium, as long as the final assembly meets certain design conditions.
In the UK, for example, a green roof system can be classified as BROOF(t4) if the underlying structural roof covering has this classification, the growing medium is at least 80 mm deep, and its organic content does not exceed 50 %.5 The Swedish National Board of Housing, Building and Planning also acknowledges that most green roofs have difficulties obtaining a BROOF(t2) rating with the standard test and therefore allows it to be replaced, in certain cases, with a project-specific fire safety analysis.6
Our solutions for roof material fire testing and classification
Measurlabs offers external fire exposure testing and classification according to all the test methods described in EN 13501-5 and CEN/TS 1187. If required, our experts can provide guidance on test specimen selection and other practical aspects of the process, including testing of complex assemblies such as green roofs.
We also offer a comprehensive range of additional fire tests for roofing and other construction materials, including reaction-to-fire testing and classification in accordance with EN 13501-1. Roof decks and substrates typically require an A1 or A2 rating under this standard for use in high-risk applications.
You can contact our experts using the form below to discuss your testing needs and to request a quote.
References
1 UK Approved Document B and Irish Technical Guidance Document B
2 Arrêté du 14/02/03 and Arrêté du 30 décembre 2011 (both in French)
3 Boverkets byggregler, BBR (in Swedish), Ministry of the Environment’s degree 848/2017 (in Finnish), Byggteknisk forskrift (TEK17, in Norwegian), and Roofings: Testing and approval conditions by ETA-Danmark (in Danish)
4 Belgian Arrêté royal du 7 juillet 1994 (in French) and German Muster-Verwaltungsvorschrift Technische Baubestimmungen (MVV TB) (in German)
5 Department for Communities and Local Government: Fire Performance of Green Roofs and Walls
6 Swedish National Board of Housing, Building and Planning (Boverket): Brandskyddskrav för taktäckning och gröna tak (in Swedish)