New fire tests fill the gap

Underlining its commitment to providing specifiers and contractors with the most comprehensive, authoritative fire test data available for light gauge steel framing, leading systems designer and manufacturer, voestalpine Metsec has teamed up with specialist insulation company, Mayplas, to fill a knowledge gap in the vital area of fire protection when using cavity barriers.

Current fire performance requirements for cavity barriers, covered by BS EN 1366-4, make no allowance for light gauge steel as a base material, leaving designers, engineers and contractors with a dilemma when using steel framing systems in conjunction with other materials, such as masonry.

Recognising this, and driven by demands from professionals in the construction industry, Metsec partnered with Mayplas to validate the predicted behaviour of Mayplas’s cavity barriers when used in conjunction with Metsec’s light gauge steel framing system, SFS.

In keeping with Metsec’s disciplined approach to performance testing, particularly fire testing, stringent preparations were made for testing to be undertaken by a leading independent laboratory and for the testing to include different sheathing boards. This would not only assure reliable, authoritative results but also provide the industry with a choice of potential solutions.

Engaging the Building Research Establishment (BRE) to undertake the testing, test frames were constructed to follow the principles of BS EN 1366-4 as closely as possible. Three different sheathing boards were used; British Gypsum Glasroc X, Euroform Versaroc and RCM Y-Wall, with different thicknesses of Mayplas MP552 cavity barriers.

The different test frame configurations were aimed at gathering sufficient information to facilitate comparison between Mayplas cavity barriers used between two skins of masonry – for which test data already existed – against use between masonry and Metsec SFS.

All of the SFS/masonry wall constructions exceeded the requirements of the individual Building Regulations which apply to each of the regions of the United Kingdom; England and Wales, Scotland and Northern Ireland..

Using Mayplas cavity barriers at 140mm thickness achieved 120 minutes’ performance for both integrity and insulation, whilst the 245mm thick barrier achieved 120 minutes of integrity and 60 minutes of insulation.

Furthermore, detailed inspection of the wall constructions after the fire testing had finished revealed that there had been no separation between the masonry and SFS, clearly demonstrating that the steel framing had not been adversely affected and proving the integrity of the solution.

Commenting on the results, Chris Holleron, Metsec’s Sales Director for Framing, states, “Naturally, we did not enter into this testing without having a good degree of confidence in the efficacy of SFS. The fact that the results are in line with those for a traditional wall construction, using cavity barriers between two skins of masonry, adds weight to the argument for using SFS in a wide variety of situations.

“The test results are a valuable addition to our comprehensive fire test data documentation and will provide specifiers and contractors with further reassurance when using Metsec construction systems.”