The Numbers That Repeat
Built around the 48" x 40" GMA pallet; sizes are nominal. See how to measure.
Beams
| Length | Pallets per level | For | Notes |
|---|---|---|---|
| 96" (8 ft) | 2 x 48" x 40" (40" face) | The standard bay | 96 - 80 = 16" to split between the end and middle gaps |
| 99" | 2 x 48" x 40" | Tight sites | Bay = 102" |
| 102" | 2 x 48" x 48" | 48" square pallets, drums | Only 6" left for all gaps; check with your supplier |
| 108" (9 ft) | 2 x 48" x 48" or 3 narrow | Square pallets, more clearance | 108 - 96 = 12" for the gaps with 48" faces |
| 120" (10 ft) | 2 pallets with extra room | Wide loads, long product | Not for 3 x 40" faces: 3 x 40 = 120 leaves no clearance |
| 144" (12 ft) | 3 x 48" x 40" (40" face) | Three pallets per level, lumber on decks | 144 - 120 = 24" for the gaps; 3 x 48" faces leave none |
Pick the span from the loaded width plus every gap, not the pallet count. Face heights: 3", 3 1/2", 4", 4 1/2", 5", 5 1/2", 6", 7" (structural). Beam spacing = load height + about 6" lift clearance + beam face; 48" loads on 4" beams run about 58" centres.
Uprights
| Depth | Pallet | Overhang per side | Notes |
|---|---|---|---|
| 36" | 48" x 40" pallets turned (40" deep), or 42" deep pallets | 2" for 40" deep, 3" for 42" deep | Less common |
| 42" | 48" pallets (the standard) | 3" | 90% of what we sell |
| 44" | 48" pallets, more deck support | 2" | Some makers' standard |
| 48" | 48" pallets flush, or 54" pallets | 0" to 3" | Decking-heavy racks, drums |
| Height | Levels (48" loads) | Where |
|---|---|---|
| 96" (8 ft) | Floor + 1 | Backrooms, retail |
| 120" (10 ft) | Floor + 1 to 2 | Small warehouses |
| 144" (12 ft) | Floor + 2 | 16 ft clear buildings |
| 192" (16 ft) | Floor + 3 | 20 to 22 ft clear |
| 240" (20 ft) | Floor + 4 | 24 to 26 ft clear |
| 288" (24 ft) | Floor + 5 | 29 to 30 ft clear |
| 360" to 480" (30 to 40 ft) | Floor + 6 to 8 | VNA, AS/RS, rack-supported |
Clear heights assume the first beam at 48", 58" between beam tops and 18" kept below the sprinklers. Your sprinkler design may need more clearance; the rack height calculator reruns it.
Column sizes: 3" x 1 5/8" and 3" x 3" (teardrop roll-formed), 3 5/8" and 4" for heavier series, C3 to C5 channels for structural. Gauges 14 (standard), 13 and 12 (heavy). Footplates 3" x 5" up to 5" x 8" with two anchor holes.
Wire Decks
| Deck (depth x width) | Frame depth | Beam length | Channels | Typical rating, spread evenly |
|---|---|---|---|---|
| 36" x 46" | 36" | 96" | 3 | 2,500 lb |
| 42" x 46" | 42" | 96" | 3 | 2,500 to 2,700 lb |
| 42" x 52" | 42" | 108" | 3 to 4 | 2,500 to 3,000 lb |
| 42" x 58" | 42" | 120" | 4 | 2,500 to 3,000 lb |
| 48" x 46" | 48" | 96" | 3 to 4 | 2,500 to 3,000 lb |
| 48" x 52" | 48" | 108" | 4 | 3,000 lb |
Two decks per bay on these spans. Sizes are nominal order sizes; a tape over the waterfalls can read different. The deck maker's rating for your exact deck and load type governs, and a uniform rating does not cover point loads. Mesh 2 1/2" x 4", 6 gauge wire. See wire deck styles.
Bays and Rows
- Bay width centre to centre = beam length + 3" column (96" beam = 99" bay).
- Row length = bays x bay width + 3". Ten 96" bays = 993" = 82' 9".
- Back-to-back rows: two frames plus a 6" to 12" frame gap: 42" + 12" + 42" = 96" of frame. With 48" pallets overhanging 3", the loads take 102" and the gap between loads is 6".
- Single row on a wall: frame depth, plus the rear overhang and the wall gap your fire design calls for.
Aisles
| Truck | Aisle |
|---|---|
| Sit-down counterbalance | 12' to 13' |
| Stand-up counterbalance | 10' to 11' |
| Reach truck | 8' 6" to 10' |
| Double-deep reach | 10' to 11' |
| Turret / VNA | 5' 6" to 6' 6" |
| Walkie stacker | 7' to 8' |
| Pallet jack / hand truck only | 6' to 7' |
Full forklift aisle width chart.
Heights and Clearances
- Top of load below the sprinkler deflectors by the clearance your sprinkler design requires. 18" is common for standard heads; ESFR heads and some commodities need more.
- Flue spaces: 6" between pallets and between back-to-back rows is common; your fire design sets it.
- First beam level: usually 48" to 60" with pallets on the floor; lower for hand-picked shelves.
- Clear height to rack height: 24 ft clear can take a 20 ft frame with 4 beam levels of 48" loads, if the first beam is at 48" and 18" is enough for your sprinklers. See the rack height calculator.
Other Systems in Brief
- Push-back: lane depth 8' 6" (2 deep) to 17' (4 deep); rails rise 3/8" to 1/2" per foot.
- Drive-in: lanes 1 pallet wide (bay 60" to 64" for 48" pallets), 2 to 10 deep, rails at each level.
- Pallet flow: lanes 2 to 20 deep on a 3/8" per foot slope, about 3 3/4" of drop per 10 ft.
- Cantilever: columns 8' to 24', arms 12" to 72", column spacing 3' to 6'.
- Mezzanine: 10' to 20' spans standard, 8' to 12' clear underneath, 125 lb per sq ft design load.
Common questions
What is the standard pallet rack size?
A 96 inch beam on 42 inch uprights, holding two 48 by 40 inch pallets per level with 3 inches of overhang front and back. 12, 16 and 20 foot uprights cover most buildings.
How wide is a pallet rack bay?
Beam length plus one 3 inch column: a 96 inch beam makes a 99 inch bay centre to centre, a 108 inch beam a 111 inch bay. Ten 96 inch bays run 82 feet 9 inches.
How far apart are beam levels?
Load height plus about 6 inches of lift clearance plus the beam face. A 48 inch load on a 4 inch beam puts levels about 58 inches apart.
What size wire deck fits a 96 inch beam?
Two 46 inch wide decks per bay, as deep as the frame; 42 by 46 is standard. 108 inch beams take 52 inch decks, 120 inch beams 58 inch.
