New fire tests on hsb elements provide unique data fire safety

Results fire tests on wall-filling hsb elements announces James Hardie at PREFAB 2019 trade show

James Hardie, a world leader in fiber cement products and a market leader in gypsum fiber and fireproofing solutions, has collected new data on the fire safety of wall-filling hsb elements. These data are the result of extensive fire tests James Hardie has conducted on these hsb elements for many years. The unique new data will be presented at the PREFAB 2019 trade show (booth 05.B055), which takes place from Oct. 8-10 in the Brabanthallen in 's Hertogenbosch. "The aim of testing this construction extensively and for many years is to find out the development of a facade fire as accurately as possible when the facade construction consists of hsb elements," says Larson van Dijk, chief engineer at James Hardie Group.

The James Hardie Group, which includes the fermacell®, JamesHardie® and Aestuver® brands, is responding to current developments in the market that call for increasingly safer built fire-safe façade structures. In recent years, James Hardie has tested various facade constructions and building nodes with facade-filling hsb elements for their behavior in case of fire. From this, unique results have emerged. "With this new test data, we can map the development of a fire in a hsb façade even better. With this we can provide the precast hsb industry with new knowledge about fire safety," says Van Dijk. The Building Code focuses mainly on the fire class of facade materials. Van Dijk continues: "But the fire class of facade materials is not the same as the fire safety of a facade. Fire class is about fire propagation across the facade. Fire safety is about how fast the fire or smoke gets into the next apartment. This includes much more than the fire class of the facade material. It is mainly about the junctions. And it is precisely these that are rarely tested."

For the fire test, two façade-filling hsb elements were placed on top of each other, with a concrete floor in between, combined with a ventilated façade construction. This included a traditional construction of hsb elements, built from inside to outside with 12.5 mm fermacell® Gypsum fiberboard, vapor-tight foil, 38×235 mm framework, filled with glass wool and on the outside a fire-retardant vapor-tight foil. Standard ventilation grilles (55 mm high) were installed in the tested facade. The tests paid particular attention to fire development in the cavity. "How the fire develops in the cavity was hardly visible before, because cladding obstructs the view. After testing the hsb elements, we found out how erratic a facade fire is and what fire does to the materials used in the hsb element," says Van Dijk. The two superimposed hsb elements showed that they more than met the residential separation requirements (WBDBO 60 min).

It also became clear that fire load is not dependent on the potential proportion of wood in the wall-filling hsb element. The additional contribution of Powerpanel H2O to fire safety in the case of a facade construction finished with a layer of stucco or stone strips was also investigated. The test shows that this cement-bound board remains extremely stable under fire loads. "The temperature rise on the inside of the HSB element is slow and the underlying fasteners, structural timber and glass wool are fully exploited. After the structural timber disappears due to the fire, the panel falls inward under its own weight. This happened during the fire test after about four hours," says Van Dijk. With this test data, James Hardie can make new calculations, such as whether fire is affected by open joints in the cladding or by rigid foam insulation, which is put over hsb elements to achieve a high insulation value with limited (wood) thicknesses. "In short, through the fire tests we have learned a lot about the degree of fire safety of wall-filling hsb elements," says Van Dijk.

James Hardie's fire tests meet the need from the market in terms of new data on fire safety among building project clients looking for hsb façade structures. "The market is currently asking for hsb elements that meet current laws, regulations and building requirements in all areas, such as noise and insulation requirements, fire resistance and air and water tightness," says Ton Borgers, key account manager of James Hardie. This trend focuses in particular on precast hsb wall constructions as a total solution, tested and certified as a total concept. With the results from the fire tests, James Hardie set to work. "We started from existing hsb elements, which are, for example, combined with new types of high-efficiency insulation to meet today's thermal requirements," Borgers explains. For example, the study includes a test report with test data on the effect of different nail spacings when fixing the Powerpanel H2O as a base for stone strips. Of these, James Hardie has prepared complete tables. "In fact, we tested a junction that closely matches reality," Van Dijk adds. These tests were performed by accredited laboratories that conduct testing at the European level. An expert paper is being written based on these tests.

"The total solution revolves entirely around timber frame construction," says Peter Vriens, commercial director Benelux. He points out that to investigate the total concept, James Hardie worked intensively with other manufacturers, such as adhesive and stone strip manufacturers, whose products are used in the timber frame elements. "With them, we established concrete LTAs of the technical systems of the total solution in timber frame construction with clear instructions and directions for the contractor applying the systems. This method offers the customer security and guarantee on the closed elements and the standard details of the hsb façade element. According to Borgers, this total solution is based on three pillars: complete unburdening, safety and security. "With this hsb façade construction, fire predictions can be made that approach reality. In addition, the precast construction relieves the contractor, because it allows him to achieve efficiency gains and failure cost reductions when realizing his project. Prefabrication has the future and will change the way of thinking throughout the construction column," Borgers said.

Fermacell BV operates in the international building materials market with system solutions for dry construction. The company produces and supplies gypsum fiber boards, floor elements and cementitious boards. Fermacell products are highly sound-insulating, impact-resistant, moisture-resistant and fire-retardant. In addition, they contain no harmful substances and are 100% recyclable. For more information: www.fermacell.nl For more information specifically regarding fermacell Fire Resistant Systems, download the new Fire Book here: https://www.fermacell.nl/brandboek

Fermacell BV is part of the James Hardie Europe Group and also sells facade fiber cement products (for more information: www.jameshardie.nl).