Steady Ground: Critical Elements of Warehouse Floor Construction

 

When it comes to warehouse efficiency, a solid foundation is not just a metaphor. The flatness and smoothness of your warehouse floor set the stage for everything from the stability of your pallet racking to your forklifts’ ability to navigate safely, and the protection of inventory and your employees. You can have the most reliable racking systems in place, but if your storage system is on unstable ground, it’s automatically at heightened risk for accidents, damage, and downtime.

There are indicators called the “F Numbers” that tell you the degree of your slab’s flatness. The number (FL) describes the floor’s levelness and (FF) describes your floor’s flatness.

• Floor Flatness F-Number (FF) – Measures the roughness of a slab’s surface caused by waves when the concrete is poured and smoothed out.
• Floor Levelness F-Number (FL) – The amount of slope or pitch in a floor’s surface and the degree to which it approaches or deviates from perfect horizontal positioning.

The American Concrete Institute (ACI) indicates acceptable ranges for flatness and levelness in ACI 302.1, Guide for Concrete Floor and Slab Construction. Floor flatness is an essential element in creating a sound structure but there are several other factors that must weigh-in as well.

Achieving a Super Flat Warehouse Floor

The truth is that you really only get one good shot at getting your warehouse floor to the right level of flatness and smoothness. It’s the part of your warehouse’s construction that is most vulnerable to error, and it can be the most difficult to fix. Some of the primary factors that can affect your floor’s levelness and flatness include:

Subsoil – Subsoil preparation is critical. Before pouring concrete, preliminary soil tests must be performed and the ground should be properly compacted. If not adequately prepared, the soil underneath the facility can settle, causing instability in the structure and, by extension, everything within it. Depending on the results of the soil testing, re-bar or even post-tensioning cables may be required to ensure the facility will adequately support the intended use. To that end, it is also essential to know the design of the rack system and what type of vehicles will support the warehousing efforts. Here’s why…

According to the ACI, Very Narrow Aisle (VNA) vehicles that travel a defined path require a Class 9 Super Flat floor with a minimum FF of 100.  A facility with a more random vehicle traffic pattern typically requires an FF value of 50. System height can also affect the FF level required for stability and support as well as anchoring and installation. So, where possible it is advantageous to provide the warehouse design before warehouse construction.

Slab Strength & Thickness – The required slab thickness is based on the anticipated load. Floors that require a higher tolerance (higher F-number) can be more difficult and costly to build, but will be constructed appropriately to sustain planned operations. The weights of material handling vehicles, storage racking, and support systems (conveyance, sortation, packaging, etc.) should be built into the calculation to establish the required slab tolerance. Special considerations will be given to items such as free-standing industrial work platforms that may require footings to support them properly.

Humidity and Other Weather Conditions – It is important to control both temperature and moisture as the concrete cures, which may take 60-90 days if left untreated. Extreme changes in temperature will cause your floor joints to expand and contract. It can also affect the way concrete sets and ultimately cures.

Prevent Minor Floor Damage from Becoming a Major Problem

Wear and tear on warehouse flooring from vehicles, chemicals, and abuse is likely to happen, but it’s important to address damage as it occurs to lessen the impact. Damage to the floor surface has consequences for employees, equipment, and productivity. It is more cost-effective to make repairs than to replace equipment and pay workers compensation claims.

One cost-effective way to ensure overall warehouse safety is to conduct regular safety audits and immediately fix issues as they emerge. Setting up simple procedures for reporting spills, accidents, damage, and safety issues is one simple and inexpensive way to improve warehouse function and workplace safety. Additionally, the Apex team can help train your workers to evaluate pallet racking damage and to spot general warehouse safety concerns using the free Rack Repair App. The Apex PROs can even come to your facility to train your team to spot and record issues, to learn more check out our blog, or give the team a call to schedule a class.

Let Apex Help You from the Ground Up

The Apex team is ready to provide expert guidance and insights on your next warehouse facility project, whether new construction or renovation.  Our engineers will work with you to ensure you have the resources, assets, and advice you need to ensure your operational expectations are met. Call us today for a consultation and to learn about all that we can do for you.