Backstop beams are a cost-conscious solution to ensure impediments don't clog your flue space and increase fire risk in your warehouse. 

One of the most common ways that longitudinal flue space gets choked is pallet push-through. The National Fire Protection Association has long required pallet rack flue space to remain clear so that any fires can successfully vent up rather than out, allowing sprinkler systems to activate faster. This vertical rise also helps slow fire spreading horizontally through a rack system. Flue space compliance is increasingly important to insurers and operators of warehouses and other industrial facilities.

There are two types of pallet rack flue space:

  1. Longitudinal Flue Space: the space between rack runs that sits perpendicular to the direction of loading. Put more simply – it’s the space between two runs of rack.
  2. Transverse Flue Space: the space between pallets, and between pallets and uprights.

Pallet push-through can result in blocked longitudinal flue space, even if the rows are adequately spaced and utilize row spacers.

Our customer, a global manufacturer of office furniture, was concerned that pallet push-through was going to result in product falling between the runs of rack, simultaneously endangering the expensive fire suppression system they had installed and increasing the risk of a catastrophic fire by blocking the longitudinal flue space.

After an initial site visit ASL proposed two separate systems: nylon mesh and backstop beams. Given the various constraints imposed by the fire suppression system, the customer eventually settled on backstop beams as it accomplished most of the job of nylon mesh at ~20% of the total cost.

While backstop beams are one of the most limiting options available, they were a great fit for this manufacturer as the fire suppression system that ran throughout the longitudinal flue space made it difficult to utilize a nylon mesh system or wire mesh panels. Furthermore, ASL was able to keep the cost down by designing, fabricating and installing the backstop beams.

In many cases, long runs of mesh are the most cost efficient and easiest to install, but when there are impediments such as the fire suppression system, you end up needing individual panels of mesh which complicates the installation and increases the price of the material. In the end, the customer was willing to trade assurance that product wouldn’t fall in the flue space for a much lower cost and easier installation.

A few things to keep in mind when considering adding backstop material:

  • What matters most: Preventing anything from falling or limiting the likelihood of a fall?
  • Are there impediments in the flue space? Do you have to work around existing product? Are the bays of rack standard or are they all different?
  • A lot can change between the time you give the green light and installation, so drawings are important to ensure everyone is on the same page regarding product specifications and anticipated performance
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