The short answer: take your factory’s clear height, subtract 500 mm for installation and
maintenance clearance, and that gives you your maximum rack height. A 5.5 m clear ceiling
fits a 5 m rack with 14 storage levels — enough for 42 metric tons of sheet metal in a single
tower footprint. Use the reference table below to find your number in under a minute.
Step 1 — Get Your Real Ceiling Number (Not the One on Your Lease)
Before you look at any rack spec, you need one measurement: your factory’s clear height. That’s not the floor-to-ceiling number on your building permit. It’s the distance from the floor to the lowest physical obstruction directly above your planned installation zone.
In most fabrication shops, that lowest point isn’t the ceiling itself — it’s something hanging below it:
- Roof beams and trusses — typically drop 200–400 mm below the ceiling surface.
- Fire sprinkler lines — heads must remain unobstructed. Most fire codes require 450–600 mm of clearance below the sprinkler level. Check your local code.
- HVAC ducts and conduit runs — especially in older industrial buildings that weren’t designed with tall equipment in mind.
- Overhead cranes or runway beams — if your shop has a bridge crane, its lowest travel position sets your hard ceiling.
Once you know the true clear height, subtract one more number: 500 mm. CK Metal Storage requires a minimum 500 mm clearance between the top of the rack and the lowest overhead obstruction. This isn’t wasted space — it’s what allows the installation team to work safely and gives your maintenance crew room to service the lift mechanism over the years.
Your usable rack height = Factory clear height − 500 mm
Example: your shop has a 6 m clear height with a sprinkler system at 5.8 m (200 mm drop from ceiling). Your usable rack height is 5.8 m − 0.5 m = 5.3 m, which rounds down to a 5 m rack configuration.
Step 2 — Find Your Factory in the Table
With your usable rack height in hand, here’s what CK’s Automated Sheet Tower delivers at each configuration. Figures are based on standard 3,000 × 1,500 mm sheet format at 3 metric tons per level, full load.
| Factory Clear Height | Rack Total Height | Storage Levels | Max Capacity (3T/level, full load) |
| ~4.5 m (±14’–15′) | 4 m | 10 levels | 30 metric tons |
| ~5.5 m (±18′) | 5 m | 14 levels | 42 metric tons |
| ~6.5 m (±21′) | 6 m | 18 levels | 54 metric tons |
| ~7.5 m (±24’–25′) | 7 m | 22 levels | 66 metric tons |
| ~8.5 m (±28′) | 8 m | 26 levels | 78 metric tons |
Note: the rack height in the table is the tower structure itself. Your factory clear height needs to be approximately 500 mm above that figure to allow safe installation and ongoing maintenance access.
Step 3 — What Those Numbers Mean on Your Shop Floor
The capacity figures in the table represent the maximum storage in a single tower footprint — an area roughly equivalent to two parking spaces. To put that in perspective:
- 42 metric tons in a 5 m rack is typically enough to cover a week or more of material buffer for a mid-sized laser cutting operation running two shifts.
- 54 metric tons in a 6 m rack covers most fabrication shops processing a mix of steel, aluminum, and stainless — all in one tower, fully indexed and retrievable in under 45 seconds.
- 78 metric tons in an 8 m rack is designed for high-volume operations with consistent throughput — or for shops that want to minimize replenishment frequency on high-usage grades.
For shops that need more capacity than a single tower provides, CK’s system can be configured as a double tower sharing one lift mechanism. This roughly doubles your storage positions without doubling your floor footprint — and without the cost of two independent lift systems.
One More Thing: Taller Isn’t Always Faster
It’s worth knowing that rack height doesn’t just affect how much you can store — it also affects how fast you can retrieve. CK’s lift travels at 10 meters per minute vertically, with a push/pull speed of 8 meters per minute. Here’s what that looks like in real retrieval times from the top level:
| Rack Height | Top-Level Travel | Lift Time (10 m/min) | Total Retrieval Cycle |
| 4 m | ~3.5 m | ~21 sec | ~30 sec |
| 5 m | ~4.5 m | ~27 sec | ~35 sec |
| 6 m | ~5.5 m | ~33 sec | ~40–45 sec |
| 8 m | ~7.5 m | ~45 sec | ~55–60 sec |
A 5 m rack retrieves every pallet — including the very top level — in well under 45 seconds. That’s fast enough to keep a laser cutter or punch press running without any material wait. As you go taller, top-level retrieval time inches toward the 60-second mark.
This is why around 70% of CK installations land at approximately 5 meters: it’s the point where storage density, retrieval speed, and typical factory ceiling heights all line up cleanly. For most fabrication shops, it’s the right answer — not because it’s the maximum, but because it’s the optimum.
If your ceiling gives you 6 meters or more and your throughput is high, the 6 m configuration is worth the conversation. If you’re pulling sheets dozens of times per shift, two 5 m towers will almost always outperform one 8 m tower on total daily throughput.
Your Pre-Quote Checklist
Before you reach out to CK Metal Storage for a layout recommendation, grab these four numbers. It takes about ten minutes and means we can give you a specific, accurate recommendation on your first call:
☐ Your factory clear height — floor to the lowest overhead obstruction in your planned installation zone (not the ceiling peak).
☐ Any additional obstructions — sprinkler heads, crane runways, duct lines. Note the clearance each requires.
☐ Your planned installation footprint — approximate floor area available for the tower (length × width).
☐ Your typical sheet sizes and weekly material throughput — this helps size the right configuration and determine whether a single or double tower fits your workflow.
FAQ
What is the minimum ceiling height needed for a CK Automated Sheet Tower?
The smallest standard configuration is 4 meters of rack height, which requires approximately 4.5 meters of factory clear height (rack height plus the 500 mm maintenance margin). This gives you 10 storage levels and up to 30 metric tons of capacity.
My ceiling is 5.5 meters — what can I fit?
A 5.5 m clear height fits a 5 m rack configuration comfortably, with the required 500 mm clearance above. That gives you 14 storage levels and a maximum capacity of 42 metric tons, based on standard 3,000 × 1,500 mm sheet format at 3 T per level.
Can the rack be installed next to a laser cutter or punch press?
Yes — and that’s exactly how most installations are designed. CK’s Automated Sheet Tower is built to sit directly adjacent to CNC laser cutting machines, with automated or semi-automated sheet feeding connections available. Keeping the tower close to the machine eliminates the forklift handling step entirely.
What if my ceiling height falls between two options in the table?
The table uses standard rack heights (4 m, 5 m, 6 m, 7 m, 8 m). If your usable rack height falls between two figures — say 5.3 m — you’d configure a 5 m rack. The remaining 300 mm is absorbed into the overhead clearance margin, which simply exceeds the minimum 500 mm requirement. We never build to the exact ceiling; there’s always working room above.
Is the 3-ton-per-level capacity a hard limit?
For the standard CK Automated Sheet Tower handling 3,000 × 1,500 mm format, 3 metric tons per level is the rated capacity. If your operation involves heavier plate or larger sheet formats, CK offers configurations with higher per-level load ratings. Share your material spec and we’ll confirm the right setup.