Insulation testing uncovers differences between combustible products. Since the thermal insulation industry has started preparing for the migration of SANS 428 to SANS 53501-1, testing has revealed interesting but also controversial results. The Thermal Insulation Products & Systems Association SA (TIPSASA) explains how things are changing. 

Controversy about the migration from SANS 428 to SANS 53501-1 

• Internationally, EN 13501-1 Fire classification of construction products and building elements Part 1: Classification, using data from reaction to fire tests, has been enforced since 2002. 
• The South African thermal insulation industry is officially switching over to the new fire tests methods and classification at the end of December 2024. 

South Africa is a member of the World Trade Organisation (WTO), and SANS 428 was considered to be a barrier to trade. The adopted international test methods measure the performance of the physical properties of products and offer transparency of the performance classification of products. 

From two to seven 

The previous classification of SANS 428 only had two classifications, namely non-combustible “A” or combustible “B”. It soon became clear that the results of combustible products in accordance with the new classification are very different, and even products previously classified as non-combustible are now rated “A2”, with limited combustibility.  

Combustible products are now divided into five different categories, also measuring smoke and droplets. 

There are combustible products that now perform worse than other combustible products and to add insult to injury, misinformation is being spread about the new test methods (especially the SBI) and classification. This raises the question: Are these legitimate concerns about the standard’s impact or vested interests? 

Technical performance 

The Construction Products Regulation (CPR), introduced by the European Union, laid down harmonised rules for the marketing of construction products. The Regulation provided a common technical language to assess the performance of construction products.  

One of the performance requirements for construction products is the reaction to fire performance. The basis for the European reaction to fire classification, the EUROCLASSES, was put in place in 1993 by the Fire Regulators Group.  

The classification system was based on the performance of products under different fire conditions. It is a harmonised classification system in the international arena and each country still has its own building regulations for applications. 

Room corner testing 

The test regime consisted of existing test methods accepted internationally, but the “controversial” SBI test method was developed to assess the performance of building products in a (real-scale) room corner scenario.  

The ISO 9705 room corner test, which is a full-scale test method intended to evaluate the contribution to fire growth provided by a surface product applied in a room, was put forward as the reference test for this scenario.  

• The main development objective therefore was that the product ranking in the SBI would have a high correlation with the ranking obtained in the ISO 9705 room corner test.  
• The second development objective followed from the requirement that the method had to be capable of measuring the required characteristics in a repeatable and reproducible way.  
• The research and development by fire experts were finalised after ten years and published and implemented in 2002. 

The SBI test simulates a single burning item burning in a corner of a 3x3m² test room. Eventual corner joints as applied in end-use conditions form part of the product under testing. The combustion gasses are collected in a hood and transported through a duct. The duct contains a measurement section with a differential pressure probe, thermocouples, a gas sample probe and a smoke measurement system, to measure heat and smoke production.

Safety concerns 

The introduction of SANS 53501-1 in South Africa has raised concerns about products currently listed as non-combustible, now being re-tested and classified as combustible. 

The SANS 53501-1 (BS EN 13501-1) classification comprises of three ratings. The first is the main Euro class rating, which will be the letter A1, A2, B, C, D, E or F.  

A1 is the highest level of performance, while F is the lowest. A1 products are classified as non-combustible. A2 products are classified as limited combustibility, and B to F are classified as combustible in ascending order. 

Certain products previously classified as “A” in accordance with SANS 428 are now classified as “A2” limited combustibility.  

Typical examples are homogeneous and non-homogeneous products. In layman’s terms it means that glass wool or mineral wool unfaced will receive an A1 rating and laminated glass wool products an A2 with smoke and droplets measurement. The “A2” limited combustibility implies that there is no significant contribution to fire.  

Similarly, there are also other products previously classified as non-combustible that now receive a combustible rating. This is to be expected, as the test methods are vastly different. 

Test requirements 

Misinterpretation of SANS 10400-T  

It should be noted that facades and External Thermal Insulation Finishing Systems (EIFS) are tested to different standards, namely SANS 10177-2 and SANS 8414-1/2 respectively. It is insulation products that are tested and classified in accordance with SANS 53501-1. 

Similarly, the core material of an insulated panel can have a fire classification, but the complete panel system must be tested in accordance with ISO 9705, which is now available in South Africa. 

The usage of combustible materials is allowed, provided they have been tested and are classified and used in accordance with the requirements of the building occupancy classification. 

Furthermore, SANS 10400-T is the application of the National Building Regulations Part T. It is deemed to satisfy the requirements of the regulation. Rational design is always an option. 

Education and training 

TIPSASA has actively been promoting the changes by participating in the DAS Conferences on a national level since 2023, educating professionals on the forthcoming changes. They also offer additional educational workshops and seminars for interested parties.  

With the migration of SANS 428 to SANS 53501-1,

testing has revealed interesting but also controversial results for insulation materials. 

For more information, contact TIPSASA: 

Tel: +27 861 000 334 / +27 82 305 8559 

Website: www.tipsasa.co.za