The Colorado fire that swept through and destroyed nearly 1100 houses in the 2021-22 US winter suggests the Australian construction market down under may have superior construction standards than the US construction industry with mandatory product ratings to achieve fire resistance. The Bushfire Attack Level (BAL)reporting for bushfire prone areas requires one of five levels of fire resistance rating at the development application. Choice of composite decking effects the structure’s fire resistance Could US regulators mirror the BAL rating system with a Forest Attack Level (FAL) rating system? Internationally, some composite decking choices are:
The major challenge for builders is how composite decking performs in Texan weather conditions compared to a hardwood timber deck. Composite decking manufacturers recommend 3/8” expansion gaps and a grid pattern/format due to the excessive expansion in sunlight of the product compared to timber but the composite decking advantage is higher sustainability and lack of maintenance. Composite decking comparisons are complex but can be assessed on four attributes:
TheEkologixboards have two format sizes (in four colors) of 23x88mmx5.4m and 23x137mmx5.4m at almost double lineal meter cost. Ekologixcomposite decking uses HDPE plastic throughout the entire board’s depth which means that the board maintains a more natural appearance and can be sanded. The elimination of the cap-stock or veneer coating means that the board performs better from a sustainability design perspective but is more susceptible to staining. Ekodeck’scompetitors have eliminated the staining propensity by using a PVC composite top veneer coating. The PVC top veneer reduces a boards capacity to cope with heavy knocks and punctures as the composite decking color and texture isn’t throughout the. Although cost competitive,Ekodeckcomposite decking does not achieve a BAL rating.
Millboardis sold byOutliveis 100% more costly thanOutlive standard composite boardModwood. The Australian made product is not fire-rated (or BAL rated) so the reason for the increased pricing structure could be the shear volume of required raw material as the format sizes are either approximately 3/8”x7” 2/8”x12’ lengths or 3/8”x8”x12’ lengths. The nine color range also has availability in ‘weathered’ textures. This product can only be fixed with the proprietary stainless steel star head screw. The supply cost of the boards and the associated cost of the fixings certainly will almost invariably result in this product only be specified in up-market individual houses.
Modwoodis also only available as grooved composite decking, supplied at a more competitive price thanMillboard. The most important feature ofModwood is that achieves a BAL 40 rating when using the ungrooved profile with two format sizes ofModwood are 1”x3” 4/8”x18’ and 1”x5” 3/8”x18’. Clients should remember the labor cost for fixing the boards is increased with the narrower widths when assessing the apparent supply cost savings. Modwood is available in four color shades with smooth or brushed finish. The boards are glue fixed into a galvanized, powder-coated galvanized or stainless steel proprietary fixing system (called ‘Klevaklip’).
Timber Techsupplies six ranges of composite decking and nineteen colors of varying brushed or smooth finishes internationally – the square edged XLM Plank range is the only range with a BAL 29rating. The format size is 5”2/8”x1”mm for both the square edge and grooved boards with sectional profiles similar to Trex. The reduced BAL rating means that this product is unsuitable for specification in bush fire prone areas or BAL 40.
Trex Decking offer 20 colors to the Texas construction market in square edged and grooved composite decking. The diversity of colors and quality of finish of the boards are major advantages for specifying this for your next project but lacks high fire-resistance with BAL 29 rating. Interestingly, some Australian hardwoods also achieve a BAL 29 rating. The grooved boards use the proprietary fasteners that create 2/8” gaps – AS 3959-2009 stipulates resistance against ember attack requires a 1/8” gap. Trex arguably leads composite decking technologyaccumulating thirty years of manufacturing composite decking. The format size is either 1”x5”4/8”x16’ or 1”x5”4/8”x19’5/8” so the composite decking are expeditiously installed with reduced labour than the wider and longer composite decking lengths.