FEATURE ARTICLE, AUGUST 2007

THE STORAGE BEHIND THE STORE
Developing modern, efficient distribution centers can only help retailers maintain streamlined supply chain operations.
Greg Freehauf

TCB Design Build construction workers use precast concrete wall panels to build Joliet Crossings in Joliet, Illinois. Precast concrete dominates the midwestern market as the base material for distribution center construction.

Empty shelves are something that retailers just don’t want to see. And often, it is the real estate that shoppers don’t see that can make the difference between inventory issues or successes. A seamless supply chain from the factory to the front lines is critical to making sure shoppers find what they are looking for. As competition between brands becomes fiercer each year, retailers are paying increased attention to the store behind the store, the distribution center that ensures a shop’s shelves remain stocked with the goods that customers want and need.

While not in the same league as retail stores when it comes to aesthetics, distribution centers for retail goods are not just carbon copies of one another. When building a modern distribution center, corporations must pay attention to the building’s basic features, technology and amenities to avoid operational risks or inefficiencies down the road. For example, investing in the proper fire safety systems, the latest in racking technology — and even just making sure that your building has been constructed using building materials appropriate to specific climates — can all make a huge difference to a retailer’s bottom line.

The construction of distribution centers is advancing with the rapid evolution of retail supply chain management, and the necessary technology is more than keeping pace. Whether leasing a portion of a larger building or utilizing the build-to-suit process to make sure a building is custom-designed, it is important to understand the new technologies and trends in construction in order to operate the most efficient distribution operation.

State-of-the-art racking systems and material handling equipment are being designed to most efficiently use available floor space. Correspondingly, the clear ceiling height in the average distribution buildings is reaching 32 feet. While most types of building structures and skins can accommodate this requirement, today’s soaring clear heights will require other changes to be made in the construction. Bring your eyes down from the ceiling to the floor, and you will see that the flatness rating of the floor and the thickness of the floor slab greatly affect the technology inside the building, as well as the basic features of the exterior walls. If a floor slab doesn’t have a flatness measurement of at least 1/8 to 1/4 inch, the top of the rack and its contents can lean too far into the aisles and adjacent racks, making the material handling more difficult. This structural inefficiency then translates into increased costs in the form of lost time, increased labor expenses and the possibility for a rise in damaged goods. When goods are stacked up to the full 32-foot height, the loads are substantial and will require heavier floor slabs of a minimum thickness of 7 inches.

When working with high-racking systems, once the floor and the ceiling components are established, the focus must turn to the features in between. Investing in a state-of-the-art sprinkler system that provides sufficient operational fire protection is more than an investment in life safety. In fact, if the base building’s system does not provide sufficient protection, the tenant would have to install in-rack sprinklers, which is definitely something to be avoided. The proper sprinkler system is normally a K-15 Early Suppression Fast Response (ESFR) system for the purposes of providing adequate protection of the rack area in tall racking environments. In-rack sprinkler heads are extremely expensive and are particularly vulnerable to frequent malfunctions, because of the device’s propensity to break when moving pallets of goods on and off the racks. To avoid both the initial and the ongoing expense of in-rack sprinklers, look carefully at both the racking system and the base building fire protection system to make sure they are compatible.

Most large distribution centers for retail goods are typically designed as cross dock facilities. This means that the building is designed with dock doors on opposing sides, allowing for maximum loading and unloading efficiency. The spacing for a cross dock facility is normally 12 feet. When the requirement allows for fewer doors per side, the design is planned so that the doors alternate every other space. The column spacing along the length of the building works best with 48- or 50-foot bays, depending on the racking aisle widths and rack depths. When looking at floor plans and the overall supply chain management process, it is important to remember that inventory control and racking systems must be compatible not only with the fire protection, ceiling heights and floors, but also with the docks, the essential connection from warehouse to delivery truck.

Common spacing across the width of the building can fall in the 40- to 50-foot range. Most buildings also feature larger spaces at the drive bays adjacent to the dock doors. These column spaces are normally 60 feet, while some facilities expand them to up to 75 feet, providing room for the depth of a full truckload.

The defining feature of any building is the materials from which it is constructed. Distribution centers are no exception — and it is important to note that building materials perfect for Texas may make no sense in Illinois. While many chain stores have very effectively put national design standards into place for building interiors, companies should not be tempted to do the same with the exterior components of a facility. Different climates require different materials, so every site selection decision needs to weigh the location of the building site and the availability of construction materials with careful consideration. Many national companies don’t realize that construction is a highly localized business. If a company was to construct all of its distribution facilities in the same way across the nation, it would leave savings on the table in certain locations, as well as leave itself open to skyrocketing operational costs or inefficiencies elsewhere.

In rural areas, pre-engineered metal buildings are popular due to the lack of conventional building materials nearby. These buildings have more operational restrictions, and tend to be more temperamental. They can include features such as 48- to 50-foot column spacing in the building length, but are typically the most cost effective when the column spacing does not exceed 30 feet. This is fine for certain retail operations, but may not efficient for others. In rural facilities, the operational economies are quite dependent on maintaining the metal siding as the wall material. Once the metal is substituted for a hard wall type of construction, the cost grows substantially.

In warmer climates — most notably California, Arizona and Texas — concrete tilt-up construction dominates the large distribution center market. Most retailers are attracted to this style for operational efficiencies, as it provides the ability to store as much inventory in a single location as possible. These panels are poured on the newly poured floor slab, allowed to set up and then tilted into place. The panels can be poured to more than 30 feet in width, and provide substantial flexibility for the design and location of windows and openings. However, the panels are normally not insulated and have either a stained or exposed aggregate finish. The structural system accompanying tilt-up construction is normally conventional steel and bar joist, or can even be pre-engineered structural system, depending on local economies.

In colder climates, precast concrete wall panels dominate, rather than tilt-up construction. With multiple Midwest and East Coast manufacturing plants, this construction type eliminates perimeter structural steel with its load bearing capabilities. This feature not only reduces the cost of the steel but also allows for the use of a less expensive trenched foundation.

Concrete tilt-up construction has not succeeded in colder climates for three specific reasons. Colder environments require an insulated panel, which is cost prohibitive when constructing the panel on-site and not pre-made in the plant. Additionally, there are far fewer days of suitable weather for pouring concrete in an open area in the colder regions. Lastly, the sites in such regions too often require unionized labor, further increasing the cost to form and pour the slabs.

To operate at their most efficient, retailers must remember to pay attention to the details that shoppers will never see. While consumers may only see the storefront, they will certainly feel the difference if there are inefficiencies in the store behind the store.

Greg Freehauf is president of TCB Design Build.


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