The I-65 South corridor running out of Nashville through Franklin, Spring Hill and on to Columbia is one of Middle Tennessee's defining industrial submarkets, and it holds two very different kinds of building. Franklin is a corporate headquarters town -- Nissan North America and Mars Petcare US are both based here -- with light industrial and flex space along Mallory Lane and Carothers: high-value, often low-clear, and expensive per square foot. Spring Hill is built around General Motors Spring Hill Manufacturing and its supplier base, with Columbia's Maury County manufacturing tied to the same plant further south. Racking a Franklin flex suite is a different engineering problem from racking a Spring Hill supplier building. This guide covers what changes.
Why I-65 South Buildings Are Different
In most big-box markets, the building is rarely the constraint. At Class A clear heights you are limited by your lift fleet, your SKU velocity, the sprinkler design and your willingness to trade selectivity for pallet positions. That describes the newer distribution stock on I-24 and I-40 well. It describes much of the I-65 South corridor less well.
In Franklin flex and light industrial, the building is very much the constraint. Clear height caps how many beam levels you can run, rent is high, and the design problem is extracting maximum storage from a limited cube without making the space unusable for the people who work in it. Every foot of aisle costs real money.
In Spring Hill and Columbia supplier buildings, the constraint is time. A supplier to an assembly plant is judged on whether parts arrive when the line needs them, so the question is not "how much can we store" but "how fast can we put away, sequence and ship" -- and the rack has to serve that.
Franklin: Getting Density Out of a Low-Clear, High-Value Space
When the ceiling is fixed and the rent is high, the levers are depth and aisle width rather than height:
- Measure the real clear height. The listing figure routinely overstates usable height. Design height comes off the lowest sprinkler head, duct, light fixture or joist in the bay, and in flex space those vary from suite to suite.
- Narrow the aisles where the operation allows. Narrow-aisle reach trucks, or very narrow aisle with turret trucks in the right operation, can recover a meaningful share of the floor.
- Go deeper where SKUs repeat. Double-deep or push-back trades selectivity for positions, which suits operations with multiple pallets per SKU.
- Mix in shelving and mezzanine where the product is small. Many Franklin users store cartons and parts rather than full pallets, and pallet rack is not always the right answer.
Flex buildings also bring mixed occupancy: offices, showrooms or labs in the same building as storage. That makes egress paths, fire separation and the sprinkler design part of the rack conversation from the start.
Spring Hill and Columbia: Racking for the Line
The warehousing that grows up around an assembly plant follows the production schedule. The design priorities are different from distribution:
- Buffers sized to production, not to the cube. Line-side and sequencing buffers get sized to production rate and replenishment frequency. Overbuilding storage in a supplier building often means slower picks, not more safety.
- FIFO where it matters. Pallet flow and carton flow earn their place because parts need to be used in order and pick faces need constant replenishment from behind.
- Returnable containers. Automotive supply runs on returnable racks, totes and dunnage, which take space, stack awkwardly and can change the fire classification depending on what they are made of.
- Separate zones for separate jobs. Raw material, work in progress and finished goods each have a different velocity and handling pattern. Collapsing them into one system is the usual reason a plant runs out of capacity while looking half empty.
The Ground and the Seismic Check
Every market has a slab question. Middle Tennessee's has two parts, and neither goes away just because the building is new.
The first is the ground. The Nashville Basin sits on limestone bedrock close to the surface, with karst. Building pads are often cut-and-fill over uneven rock, so slab support can vary across a single building: where fill is deep a slab can settle, while the slab over shallow rock does not. On a rack system that can show up as localized out-of-plumb and floor-level differences that have nothing to do with forklift damage.
The second is seismic. Middle Tennessee is typically ASCE 7 Seismic Design Category B or C, depending on site class and location. Under ANSI/RMI MH16.1, base-plate size, anchor count and frame bracing are checked against the site's seismic values, and drawings are sealed by a Tennessee-licensed PE.
Practical consequences:
- Anchor specification starts from the real slab. Thickness, reinforcement, joint layout and the geotechnical report all matter, and in an older flex building none of them should be assumed -- we core to verify rather than working from a catalog detail.
- Check for post-tensioning before drilling anything. Where a slab is post-tensioned, drilling into a tensioned cable is both a safety event and an expensive structural repair. Ground-penetrating radar maps the cable runs, the anchor pattern is set to clear them, and the scan record is kept -- most landlords want a copy. Do not assume a slab is or is not post-tensioned; confirm it from the building documents and, where they are unclear, from a scan.
Catching a slab conflict on paper costs nothing. Catching it during install costs days.
ESFR Sprinklers and Rack Geometry
Early Suppression Fast Response sprinklers are common in the newer and larger buildings on this corridor, and they are the reason tall storage is practical at all. But ESFR protection is designed for a specific storage configuration, and the racking is part of that configuration -- not an independent decision made afterward. In older flex space, the sprinkler system may have been designed for office or light storage use, which makes the question even more important.
Three things matter most:
- Flue space. Sprinkler designs depend on transverse and longitudinal flue spaces staying open so water reaches the seat of a fire. Rack depth, back-to-back spacing, and load overhang all affect this. Closing off a flue to gain a few inches of storage can undermine the sprinkler design.
- Clearance to sprinkler heads. NFPA 13 requires minimum clearance between the top of storage and the sprinkler deflector. This is what actually caps your top beam level -- not the deck height. We spec uprights against the lowest sprinkler head in the bay, every time.
- Solid shelving and decking. Solid decking blocks vertical water penetration. Where solid shelves or containment decking are needed, that generally has to be reconciled with the sprinkler design, sometimes with in-rack heads.
This coordination step is where corridor racking projects most commonly stall. We bring the facility's sprinkler engineer into the conversation before rack drawings are finalized rather than discovering a conflict during plan review.
Choosing a Storage System for This Corridor
The usual options, and where they fit on I-65 South:
Selective rack remains the baseline. Every pallet is directly accessible, it suits high-SKU operations, and it is the simplest system to permit, install, and modify later -- which matters in flex space where tenants change.
Double-deep selective roughly halves your aisle count in exchange for a deep-reach truck and second-position access delay. It works well where SKUs come in pairs of pallets and the operation can tolerate the honeycombing.
Push-back rack, two to six deep, stores on nested carts on inclined rails. It is LIFO, so it fits operations with moderate SKU counts and multiple pallets per SKU. Density gain is substantial in a low-clear building where height is not available.
Pallet flow and carton flow are gravity-fed FIFO -- loaded at one end, picked at the other. They are the natural fit for supplier buildings feeding a production line. They cost more per position and demand more maintenance than static rack.
Very narrow aisle (VNA) with turret trucks recaptures the most floor of any option by cutting aisles substantially. It requires wire guidance or rail, a tight floor flatness tolerance, and a fleet commitment. That flatness requirement deserves attention here: a floor sitting on cut-and-fill over uneven rock can move differently from one area to the next, so VNA is a commitment to verifying and maintaining the floor as well as buying the trucks.
Permitting: Which Jurisdiction Are You Actually In?
This is the question that costs people weeks on this corridor, and it is not obvious from the address.
Tennessee adopts building and fire codes statewide through the State Fire Marshal's Office, and cities and counties that enforce their own codes are "exempt" jurisdictions that do their own plan review. Along I-65 South the local answer changes several times:
- Metro Nashville. The northern end of the corridor is inside the consolidated Metro government, where Metro Codes reviews the building permit and the Nashville Fire Department Fire Marshal's Office handles high-piled review.
- City of Franklin. Franklin runs its own codes department and fire department, in Williamson County.
- Spring Hill. Spring Hill straddles Maury and Williamson counties and runs its own codes and fire departments inside city limits. The county a parcel sits in matters for anything outside the city.
- Columbia and Maury County. The City of Columbia reviews work inside city limits; unincorporated Maury County goes through the county building codes office, and in some unincorporated areas plan review routes through the State Fire Marshal's Office.
On top of the jurisdictional question, IFC Chapter 32 high-piled combustible storage requirements generally apply where the top of storage exceeds 12 feet, or 6 feet for high-hazard commodities. Under the model code, an operational permit is required above 500 square feet of high-piled storage area; confirm whether the local office has amended that.
Commodity classification drives how demanding that review gets. Group A plastics carry the most stringent requirements in Chapter 32 and can require in-rack sprinklers, and classification depends on the product and its packaging rather than on your industry. Automotive parts in plastic returnable totes, shrink wrap or foam dunnage can land in the high-hazard band. Classify before you design the rack; it changes the answer.
Submitting the building permit and the high-piled storage review the same day keeps them concurrent. Sequential submittal is the single most common self-inflicted schedule delay we see on these projects. See pallet racking permits in Greater Nashville for the full sequence.
Working Around a Live Operation
Many buildings in this corridor are racked while running. A supplier cannot stop shipping to the plant, and a Franklin tenant may be sharing the building with its own offices. Phased installation in a live building is standard work, and it comes down to sequencing: work zone by zone so operations continue elsewhere, barricade active areas, schedule noisy and dust-producing work outside peak hours, and stage material so lift-truck lanes stay clear.
Supplier operations tied to a production schedule frequently require nights and weekends. That is a scheduling question, not an obstacle -- but it needs to be priced and planned at quote time rather than discovered in week two.
Practical Steps for I-65 South Racking Projects
- Confirm the reviewing office from the parcel, not the address. Metro Nashville, City of Franklin, City of Spring Hill, City of Columbia, and unincorporated Williamson or Maury County are different answers, and Spring Hill straddles two counties.
- Measure the building. Real clear height to the lowest obstruction, column grid and sprinkler design, especially in flex space where suites differ.
- Verify the slab before the anchor pattern is set. Confirm thickness and construction, check for post-tensioning and scan where the documents are unclear, and treat karst and fill transitions as design inputs alongside the seismic check.
- Classify your commodity before you call a racking company. Whether your product and packaging falls into Class I through IV or into the high-hazard band under IFC Chapter 32 shapes rack height, in-rack sprinkler requirements, and the fire review.
- Design for the job the building does. In Franklin flex, density from depth and aisle width; in a Spring Hill or Columbia supplier building, flow, FIFO and buffers sized to the line.
Nashville Pallet Rack serves Franklin, Spring Hill and Columbia. Call (615) 551-3677 to start a project.