The manufacturer’s moisture-resistant BluClad panels were most effective, protecting against fire for 120 minutes but all those tested, including Paintboard and Duripanel, could protect for more than 30 minutes from either side of the construction.
All of Marley Eternit’s fibre cement products (decorative cladding panels, building boards and profiled roof sheets) have the reaction to fire classification Class A2, s1, d0. This is the second highest category and includes products which do not significantly contribute to fire load and growth. In addition, the s1 classification is the lowest for smoke production as is d0 for flaming droplets and particles
The products are also defined as Materials of Limited Combustibility by the Building Regulations 2002 Approved Document B (Fire Safety) and meet the requirements of Class O materials.
The latest tests were carried out on a variety of external wall constructions generally used as the non-load bearing wall element behind external rainscreen cladding panels, with vertical timber battens or aluminium profiles generally fixed to the timber or steel frame construction to receive fixings from the rainscreen system.
The boards were tested on wall constructions comprising 100mm-deep studs of timber or metal, filled with two layers of 50mm-thick mineral wool, with staggered joints.
The best performance was by Marley Eternit’s 10mm BluClad external render board. A skin of this either side of a timber frame gave 120 minutes of fire resistance. Up to 90 minutes of fire protection was given by a single layer of 9mm general-purpose, external grade Paintboard either side of a timber frame, and 30 minutes on a steel frame.
And Duripanel, a smooth and highly durable cement bonded particle board that is ideal as an alternative to chipboard or plywood for use in load-bearing situations, gave 60 minutes of fire protection on a steel frame, using 12mm on each face.