Four test methods under TS 1187:

• Test 1 – Germany
• Test 2 – Scandinavia
• Test 3 – France
• Test 4 – UK

TS 1187, Test 4 has been adopted into England’s Approved Document B (ADB) and other relevant guidance. TS 1187, Test 4 evaluates:

• Flame spread across the roof surface
• Fire penetration
• Flaming particles/debris falling from the underside

Roof systems are evaluated on flame spread and fire penetration. BROOF (t4) systems must meet specific safety criteria and can be used freely when installed within 6m of any boundary.

Criteria for BROOF (t4) Compliance

To get a BROOF (t4) certificate, the roofing system should meet the following points:

• No internal penetration of fire through the roof deck within 60 minutes
• Burn time under 5 minutes after test flame removal
• Flame spread must be less than 0.38m
• No penetration or flaming debris

Industry Study by BRE & Warringtonfire

Study Aim To identify the worst-case scenario for fire resistance in roof decks when exposed to a standard roof system (per TS 1187, Test 4). Study Objective To determine fire penetration times (up to 60 mins) for various common roof deck types to support BROOF (t4) classification:

• Profiled Steel (0.7 mm, unperforated)
• Plywood (18 mm, Class 3.2, External ‘S’, Structural)
• Oriented Strand Board (OSB3, 18 mm, non-FR)
• Calcium Silicate Board (11.5 mm) – commonly used as a test substitute for concrete decks

Once penetration times are confirmed, specifiers and building owners can be confident that a roof system is likely to meet BROOF(t4) when used with these decks. Test Results Summary

Roof Deck Type	Average Penetration Time	Notes
Profiled Steel 0.7mm	No penetration	Refer to BRE report P118474-1000
Plywood 18mm	41.44 mins
OSB3 18mm	Not determined	Test equipment unable to measure
Calcium Silicate Board 11.5mm	No penetration

Study Conclusion Based on the test results, it was found that if a roof system has already been tested using 18mm plywood or non–fire-retardant OSB3 boards, then switching to a 0.7mm or thicker non-perforated steel deck or a concrete deck should not affect how the system performs in terms of fire penetration. That is because plywood and OSB3 are considered the worst-case options. So, if the original system passed and was rated BROOF (t4) with one of those materials, it should still meet the same rating even if the deck is changed to steel or concrete.