Grenfell changing warehouse design
13 April 2021
The tragedy has had a demonstrable impact on how warehouses are being physically designed, says Harry Watts.
The reverberations of the Grenfell tragedy have rightly been felt throughout our society. Grenfell is an awful reminder of the importance of effective regulation and effective, considered design. Naturally, as an essential workplace, the warehouse has not been excluded from the national inquest into how we can make our residences and workplaces safer. Three years on from the tragedy, a long, hard look inwards has resulted in a demonstrable impact on how warehouses are being physically designed; and the materials being utilised.
Since Grenfell, there has been a significant push towards incorporating more sophisticated computer modelling of fire spread, as well as enhanced sprinkler and smoke detection technologies into facility design. These developments and reduced regulatory tolerance for fire-risk mean that to enable sprinkler systems to be most effective, permeability between floors is required. Consequently, for traditionally non-fire-rated structures such as rack-supported floors, there has been a drive towards steel mesh decking in both picking levels and flooring. Mesh-based materials are effectively replacing their chipboard and timber-decking counterparts in these solutions, with the increased cost of mesh versus chipboard worthwhile for the safety benefits they bring.
Mesh grating's permeability results in less dense smoke (which is typically more lethal than flames) than solid chipboard flooring. Smoke cannot become trapped underneath floors, and visibility is enhanced, so warehouse staff working on a mezzanine floor will be able to see and assess the situation immediately and react accordingly. Mesh is also not a source fuel - one of the three elements that cause fire outbreak - and consequently, when compared with timber products, reduce the risk of fire breakout occurring on its own or when exposed to fire hazardous substances such as paint vanish, archive papers, office paperwork, stored timber and accumulated sawdust.
Due to these safety benefits, mesh grating can now have some operational advantages compared with other materials. Longer shelving runs in multi-tier solutions are permissible due to the safety advantages, and mesh can improve space utilisation since sprinklers can deluge unimpeded through the floor, making fire baffle zones unnecessary. In some cases, this can offer an increase of up to 33% in storage capacity.
While the use of mesh is undoubtedly growing in a post-Grenfell world, it's not without sacrifice. The expense of utilising mesh rather than chipboard in rack-supported structures is significant and makes fire-rated mezzanine floors an increasingly economical alternative. Mezzanines generally offer more flexibility since they can be easily repurposed or reconfigured. Additionally, they continue to incorporate solid chipboard flooring safely (fire-rating negates the need for permeability), which has health and privacy benefits for employees. Walking and rolling equipment across mesh can be both noisy and more difficult than on a smooth solid surface.
Understandably, Grenfell forced an immediate response by changing warehouse design to incorporate pre-existing materials and technologies that provide additional protections. However, it will be interesting to see whether technological or material innovation steps up to respond to the notable operational or cost disadvantages this has resulted in - or whether the industry will just accept the cost of safety as a price worth paying.
Harry Watts, managing director, SEC Storage
For more information, visit www.sec-storage.co.uk