Incorrectly dimensioned pallet racking costs you floor space, safety and money. An upright spacing that is too tight forces the forklift driver to work to the millimetre and produces impact damage; a grid that is too wide wastes several hundred square metres of storage space per hall. If you size level loads too tightly, you only see the damage when the beam first deflects; if you forget the impact protection, you see it at the first destroyed corner upright. This article guides you rigorously through the dimensioning of pallet racking, from load assessment through upright spacing to standard-compliant impact protection in accordance with DIN EN 15512 and DIN EN 15620.
Basic terms in pallet racking dimensioning
Before you plan a pallet rack, four parameters must be fixed: bay size (centre-to-centre dimension), rack depth, overall height and the number of storage levels. These four values are not chosen freely, but derived from the stored goods, the handling equipment and the building.
Bay size (centre-to-centre dimension)
The centre-to-centre dimension is the distance from upright centre to upright centre of two adjacent frames. It determines how many pallets can be stored per level. For two Euro pallets stored crosswise (1.200 mm width) the standard dimension is 2.700 to 2.825 mm, for three pallets crosswise 3.600 to 3.900 mm. The clearances between pallet and upright are specified as minimum values in DIN EN 15620 (more on this later).
Rack depth
The rack depth (frame depth) depends on the pallet depth. Euro pallets are stored lengthwise (depth 1.200 mm), which results in standard frames of 1.100 mm. Industrial pallets (1.000 × 1.200 mm, stored crosswise) require 900 mm frame depth. The pallet may overhang 50 mm towards the operating side; at the rear (double rack) the centre gap must be taken into account as push-through clearance.
Height and storage levels
The usable rack height is limited by two factors: lift height of the forklift (counterbalance truck approx. 6.500 mm, reach truck up to 12.500 mm, narrow-aisle truck up to 17.000 mm) and clear building height minus fire protection and sprinkler clearance. For sprinkler systems in accordance with VdS CEA 4001, at least 500 mm must be kept clear between the top of the stored goods and the sprinkler level. Per storage level, allow for pallet height + load + 150 mm lift clearance + beam height.
Pallet and load assessment as the starting point
Every pallet racking dimensioning exercise starts with a realistic assessment of the load units. It is not the ideal goods that matter, but the heaviest and bulkiest goods actually stored.
Standard pallets and their weights
| Pallet type | Dimensions (mm) | Tare weight | Max. load | High-bay load |
|---|---|---|---|---|
| Euro pallet (EPAL 1) | 1.200 × 800 × 144 | approx. 25 kg | 1.500 kg dyn. / 4.000 kg stat. | 1.000 kg dyn. |
| Industrial pallet (CP3) | 1.200 × 1.000 × 144 | approx. 35 kg | 1.250 kg dyn. | 1.000 kg dyn. |
| Düsseldorf pallet | 800 × 600 × 144 | approx. 8 kg | 500 kg | n/a |
| CHEP pool pallet | 1.200 × 1.000 | approx. 30 kg | 1.250 kg | 1.000 kg |
| Mesh box (BoxPal) | 1.240 × 835 × 970 | approx. 75 kg | 1.500 kg | 1.000 kg |
Please note: the high-bay load is significantly lower than the maximum floor stacking load. A Euro pallet stacked on the floor may carry 4.000 kg statically, but in the rack level only about 1.000 kg dynamically, because the load is concentrated on two support points (the beams). This reduction is documented by EPAL and in DIN EN 15512.
Recording special formats
Special pallets (longer than 1.200 mm, one-way pallets of varying quality, coated wooden pallets) are the most common cause of impermissible point loads on the beam. Record these pallets separately with their outer dimensions, weight including load and condition class. For one-way pallets, the note from DGUV Information 208-061 additionally applies: they are not approved for high-bay storage if their load-bearing capacity has not been verified.
Upright spacing: centre-to-centre dimensions and tolerances
The upright spacing is the most important planning decision, it can only be corrected later by dismantling. Three parameters determine the centre-to-centre dimension:
- Number of pallets per bay (2 or 3 crosswise)
- Pallet width (800 mm for Euro, 1.000 mm for industrial)
- Clearances in accordance with DIN EN 15620
Standard grid dimensions
| Loading | Centre-to-centre (mm) | Remark |
|---|---|---|
| 2 Euro pallets crosswise | 2.700–2.825 | Industry standard |
| 3 Euro pallets crosswise | 3.600–3.900 | For wide aisles |
| 2 industrial pallets crosswise | 2.300–2.400 | 1.000 mm pallet width |
| 2 mesh boxes | 2.700–2.825 | Same as Euro |
| 2 Euro pallets lengthwise | 1.900–2.000 | Rare, only with deep frames |
Clearances in accordance with DIN EN 15620
DIN EN 15620 (tolerances, deformations and clearances for static racking systems) specifies binding minimum distances that must be maintained after deformation under maximum load:
- Between two pallets in a bay: at least 75 mm (classes 200/300A) or 100 mm for narrow-aisle installations with inductive guidance.
- Between pallet and upright (lateral): at least 75 mm when operated with a counterbalance truck, 100 mm with a reach truck.
- Vertically above the load unit to the next beam: at least 75 mm lift clearance, at least 100 mm for automated storage and retrieval machines.
- Push-through clearance: in double racks, at least 50 mm distance between the rear sides of both pallets and the push-through protection.
For a centre-to-centre dimension with two Euro pallets, the calculation is: 75 mm (upright left) + 800 mm + 75 mm (centre) + 800 mm + 75 mm (upright right) + 2 × 90 mm upright width = 2.005 mm clear dimension or approx. 2.700 mm centre-to-centre with a 90 mm upright width and four clearances. Established manufacturers therefore offer fixed centre-to-centre dimensions in 100 mm increments, larger clearances are a safety bonus, not a technical disadvantage.
Load assumptions: level load, bay load, stability
The permissible loads are standardised in DIN EN 15512:2020. You need to know and cross-check three values:
- Level load (F_F): maximum permissible load on one beam pair with even distribution across the bay width.
- Bay load (F_R): maximum permissible total load of one rack bay (two frames, all levels). Determined by the buckling capacity of the upright and the floor anchors.
- Stability: ratio of overturning to restoring moment. A factor ≥ 2,0 is mandatory.
Worked example: standard pallet rack for Euro pallets
Initial data:
- 2 Euro pallets per level, each 900 kg gross (industrial end product)
- 5 storage levels + floor level = 6 storage positions vertically
- Centre-to-centre 2.700 mm, frame depth 1.100 mm, frame height 7.000 mm
Level load calculation:
2 pallets × 900 kg = 1.800 kg per level. Selected beam: SCHULTE TS 90 (90 × 50 × 1,5 mm) with a permissible level load of 2.700 kg. Utilisation: 1.800 / 2.700 = 67 %, sufficient reserve, deflection < L/200.
Bay load calculation:
6 levels (incl. floor level) × 1.800 kg = 10.800 kg per bay. Selected frame: SCHULTE R 90 (90 × 45 mm upright, 1,8 mm wall thickness) with a permissible bay load of 13.000 kg at H 7.000 mm. Utilisation: 10.800 / 13.000 = 83 %.
Point load under the upright:
Half the bay load per frame = 5.400 kg, divided between 2 uprights = 2.700 kg per upright foot. With a base plate of 120 × 120 mm = 144 cm², this results in a surface pressure of 187 N/cm² or 1,87 N/mm², uncritical for industrial floors of class C25/30.
Stability:
With an H/B ratio of 7.000 / 1.100 = 6,4, floor anchoring with M12 chemical bonded anchors (ETA test certificate) is mandatory. Otherwise the factor is < 2,0.
Impact protection: what the standard requires
Corner uprights at aisle ends and cross aisles are the most common damage points in pallet racking. DGUV Information 208-061 and DIN EN 15512:2020 therefore mandatorily require impact protection on every corner upright of racking installations operated with forklift trucks.
Geometric requirements
- Minimum height: 400 mm above the top of the finished floor.
- Minimum distance to the frame: 100 mm (the impact protection must not touch the upright in the event of an impact).
- Independent floor anchoring: the impact protection is anchored separately, never fixed to the rack foot.
- Signal colour: yellow-black in accordance with DIN 4844 / ASR A1.3.
Energy absorption
In accordance with DIN EN 15512 Section 9.7.4, the impact protection on corner uprights must absorb an impact energy of at least 400 Nm without loading the upright behind it. This energy corresponds roughly to a counterbalance truck with a deadweight of 1,5 t plus load at an impact speed of 1 km/h. For upright protection inside the aisle (not at corners), 150 Nm is sufficient.
Corner protection vs. upright protection
| Type | Location | Energy | Design |
|---|---|---|---|
| Corner protection (corner impact guard) | Outer corner at aisle end | ≥ 400 Nm | L-profile, 400 mm on both sides, 4-hole anchoring |
| Upright protection | Inside the aisle, single upright | ≥ 150 Nm | U-profile or plastic, 1- to 2-hole anchoring |
| Drive-through protection | Cross aisles in long installations | ≥ 400 Nm | L-profile on both sides or welded steel tube |
| High-performance polymer | Universal, fewer floor anchors | ≥ 400 Nm | deforms elastically |
Floor loading and structural analysis
The hall floor is the often overlooked bottleneck. Modern new logistics buildings are designed for 50 kN/m² (5 t/m²) distributed load and a 70 kN point load. Existing halls, especially buildings from before 1990 or converted production halls, often do not achieve these values.
Point load under the upright foot
For a heavy pallet rack with a 13 t bay load and two uprights per frame, the vertical load per upright is approx. 6,5 t (65 kN). On a base plate of 120 × 120 mm this corresponds to a surface pressure of 4,5 N/mm². For industrial floor class C25/30 this is permissible, for class C20/25 it is borderline, here load distribution plates 250 × 250 mm must be used.
Floor anchors
DIN EN 15512 requires mechanical anchoring of every frame. For standard pallet racking, chemical bonded anchors M12 with test certificate (ETA) and a minimum embedment depth of 80 mm are sufficient. For top-beam heights > 9 m or high loads, M16 or heavy-duty anchors are used. Important: the anchoring must not be placed in joints or through bonded screed.
Industrial floor classes at a glance
| Class | Compressive strength | Application | Suitable for pallet racking |
|---|---|---|---|
| C20/25 | 20 N/mm² | Standard warehouse halls | Up to 9 t upright foot load + load distribution plate |
| C25/30 | 25 N/mm² | Modern industrial floors | Up to 13 t upright foot load directly |
| C30/37 | 30 N/mm² | High-bay warehouses, narrow aisle | Up to 20 t, automated warehouses |
| Screed on separating layer | variable | Older buildings, office areas | Not suitable, structural assessment required |
Safety distances and aisle widths
The aisle width influences space utilisation, throughput and safety. It results from the handling equipment used plus normative safety distances in accordance with DGUV Regel 108-007 / DGUV Information 208-061 and DGUV Information 208-022 (safety in in-house traffic).
Aisle widths by handling equipment
| Handling equipment | Working aisle width | Typical height | Remark |
|---|---|---|---|
| Counterbalance forklift | 3.500–4.200 mm | up to 6,5 m | Wide variant, classic |
| Reach truck | 2.700–3.000 mm | up to 12,5 m | Moving-mast truck, most common solution |
| Narrow-aisle truck (3-way) | 1.600–1.800 mm | up to 17 m | Inductively/mechanically guided |
| VNA very narrow aisle | 1.500–1.650 mm | up to 17 m | Very narrow aisle, high space utilisation |
| High-bay stacker crane (S/R machine) | 1.450–1.550 mm | up to 45 m | Fully automated, high-bay warehouse |
Safety distances in accordance with DGUV
For traffic routes in the warehouse, DGUV Information 208-022 applies in conjunction with ASR A1.8 (traffic routes):
- Forklift traffic only (no pedestrians): widest load unit + 200 mm buffer on both sides.
- One-way traffic, forklift + pedestrians: widest load unit + 1.000 mm safety distance to wall/rack.
- Two-way forklift traffic: double load unit + 400 mm safety distance in the middle + 500 mm each to the wall.
- Escape routes: at least 1.250 mm width (ASR A2.3) with up to 200 people in the catchment area.
Common planning errors
- Upright spacing too tight for the real pallet width: anyone calculating with the nominal pallet width of 800 mm forgets excess width due to stretch wrapping, protruding loads or warped pallets. Always plan with 820–850 mm as the design width.
- No allowance for additional levels: raising the number of storage levels later requires taller frames, stronger floor anchors and possibly a fire protection upgrade. Provide at least one reserve level in the initial planning.
- Fire wall clearance ignored: with T90 fire walls, racking must keep a 500 mm distance (VdS 2199); this distance often only becomes a requirement during the fire protection assessment and costs a complete rack bay.
- Double rack without push-through protection: in double racks, rear stops or separating mesh must be installed so that pallets cannot fall off at the back.
- Floor level calculated like an elevated level: the floor level bears directly on the hall floor and does not count towards the bay load, but it needs no beams, which is often forgotten in the design.
- Narrow-aisle racking with counterbalance truck dimensions: narrow-aisle installations need increased clearances (class 400 in accordance with DIN EN 15620), tighter floor flatness tolerances (DIN 18202 Table 3, row 4) and inductive guidance. Anyone who fails to take this into account will have impact damage on every third upright after 6 months.
- Seismic design forgotten: in earthquake zones 1–3 (Rhine Graben, Lower Rhine, Swabian Alb), design in accordance with DIN EN 16681 is mandatory, with frame bracing and, where necessary, additional cross bracing.
Frequently asked questions
Do I need a structural engineer for every pallet rack?
No. For standard racking from the product ranges of reputable manufacturers, the structural analysis is covered by type approval in accordance with DIN EN 15512. An external structural engineer is required for self-assembled installations, combined rack types in one row, special geometries or unclear floor load-bearing capacity.
How often must pallet racking be inspected?
DIN EN 15635 and DGUV Information 208-061 require an annual racking inspection by a competent person. In addition, weekly visual checks by the person responsible for the warehouse are mandatory. Damage leading to a "red" classification (e.g. an upright with deformation > 5 mm) requires immediate decommissioning.
Which upright height matches which aisle width?
Rule of thumb: up to 6 m upright height, the counterbalance truck is economical. Between 7 and 12 m, the reach truck dominates. From 9 m, narrow-aisle operation becomes attractive because space utilisation increases by 35–45 %. From 12 m, only narrow-aisle operation or fully automated high-bay warehouses (stacker cranes) make sense.
How far may a pallet overhang?
In accordance with DIN EN 15620, a maximum of 50 mm towards the operating side and 0 mm towards the rear for double racks without push-through protection. With push-through protection, a defined overhang may be permitted at the rear, but this is not recommended in practice.
What does standard-compliant impact protection cost?
A steel corner guard with 400 Nm energy absorption costs 35–70 € each to purchase; for an installation with 40 corner uprights this amounts to 1.500–3.000 €. Polymer impact protection costs 180–350 € each, considerably more expensive to buy, but maintenance-free and gentler on the hall floor in the long term, because no anchors work loose.
What is the difference between impact protection and push-through protection?
Impact protection protects the upright from mechanical damage by the forklift. Push-through protection prevents pallets from being pushed out of the back of the rack during loading. Both are independent safety devices governed by different standards (DIN EN 15512 and DIN EN 15620 respectively).
Conclusion
Dimensioning a pallet rack is not a catalogue exercise but an engineering problem with clear technical input parameters: load unit, handling equipment, floor structure and building envelope. If you consistently derive the upright spacing from the real pallet width and the clearances of DIN EN 15620, you build a rack that works flawlessly for over 20 years. If you verify loads separately as level, bay and point loads and check the floor pressure against the industrial floor class, you avoid expensive retrofits. And if you plan impact protection not as an accessory but as a normatively required component in accordance with DIN EN 15512, you protect material, personnel and insurance premiums. Invest the planning time at the start, in operation it pays back many times over.