- Written by
- Scaffold Exchange Team
- Published
- September 26, 2026
- Reading time
- 6 min
How scissor lift sizes work
Platform height is the height of the platform floor at full elevation. Working height is platform height plus about 6 ft, the reach of a standing worker, and is what some rate cards quote. A "19 ft scissor" has a 19 ft platform and a 25 ft working height. Rent by the height of the work, not the height of the ceiling.
Model numbers encode the two things you need. Genie GS-1930 is 19 ft platform, 30 in wide; GS-2632 is 26 ft, 32 in; GS-3246 is 32 ft, 46 in; GS-4047 is 40 ft, 47 in. JLG and Skyjack use the same idea (JLG 1932R, Skyjack SJIII 3219). Once you can read the number you can tell from the rate card whether the machine fits your door.
The four slab classes
| Class | Platform / working height | Rated load | Width | Weight | Typical use |
|---|---|---|---|---|---|
| 19 ft | 19 / 25 ft | 500 lb | 30 to 32 in | 2,700 to 3,000 lb | Fits a standard door and most elevators; retail, office, ceilings to about 24 ft |
| 26 ft | 26 / 32 ft | 500 lb | 32 in | 4,300 to 4,700 lb | Still fits a 36 in door; the most rented class for commercial fit-out |
| 32 ft | 32 / 38 ft | 700 lb | 46 in | 5,600 to 6,000 lb | Warehouse and high-bay work; needs a double door or roll-up |
| 40 ft | 40 / 46 ft | 770 lb | 47 in | 7,300 to 7,800 lb | Distribution centres, arenas, tall atria; check the slab |
Every class has a platform that extends 3 to 4 ft past the chassis on one end (the "deck extension"), which is how a scissor works over a low obstacle or up to a wall the chassis cannot touch. The extension usually has a lower load rating, printed beside it. Stowed height is 7 to 8 ft with the rails up on the 19 and 26 ft classes; the rails fold on most machines to get under a 6 ft 8 in door.
Rough terrain scissor lifts
Rough terrain scissors are a different machine: four-wheel drive, diesel or dual-fuel, foam-filled lug tyres, a wider chassis, often outriggers or a self-levelling system, and gradeability of 25 to 40 percent. They are built for graded sites, gravel and compacted fill, and they carry more: 1,000 to 1,500 lb on platforms 5 to 6 ft wide and up to 12 ft long with the extension out.
| Class | Platform height | Rated load | Width | Weight | Example models |
|---|---|---|---|---|---|
| 26 ft RT | 26 ft | 1,250 lb | 69 in | 6,700 to 7,500 lb | Genie GS-2669 RT, JLG 260MRT |
| 33 ft RT | 33 ft | 1,000 lb | 69 in | 7,900 to 8,800 lb | Genie GS-3369 RT, Skyjack SJ6832 RT |
| 43 ft RT | 43 ft | 1,500 lb | 90 in | 13,000 to 15,000 lb | Genie GS-4390 RT, JLG 4394RT |
| 53 ft RT | 53 ft | 1,500 lb | 90 in | 16,000 to 18,000 lb | Genie GS-5390 RT, JLG 530LRT |
On a site where the ground is soft, sloped beyond the machine's rating, or crowded with spoil, trenches and stacked material, a rough terrain scissor still may not be able to set up. That is where a frame scaffold on sills goes in instead; the comparison guide covers the trade.
Fitting the machine to the building
Doors and elevators
A 19 ft or 26 ft slab scissor at 30 to 32 in wide fits a standard 36 in door with the rails folded. Most passenger elevators take a 19 ft machine (about 6 ft long, 2,800 lb); confirm the car's rated load and door height with building management before delivery. Anything 32 ft and up needs a double door, a roll-up or a loading dock.
Floor loading
The whole machine weight sits on four small wheels, so the point load is high. A 32 ft scissor at 5,900 lb puts roughly 1,500 lb on each wheel over a few square inches. Raised access floors, plywood decks, mezzanines, parking decks, and slabs that are still curing all need a check. Ask the supplier for the wheel load figure and give it to the engineer or building owner.
Surface and slope
Slab scissors are rated for firm, level surfaces and a slope of only a few degrees in each direction; most have a tilt alarm that stops elevation beyond it. They are not for gravel, grass, or a sloping car park. Non-marking tyres are standard on electric models for finished floors.
Overhead
Know the stowed height with rails up (about 7 ft 6 in on a 19 ft machine, more on larger ones) and the overhead hazards along the route: duct, sprinkler mains, door headers, low mezzanines. Crushing against overhead structure is one of the two most common scissor lift fatalities, and it happens while driving as often as while elevated.
Rated load and what counts
Rated load includes everyone on the platform plus every tool, fixing, cable reel, bucket and sheet of drywall. A 500 lb machine with two 200 lb workers has 100 lb left. Manufacturers also limit the number of occupants, usually two on the slab classes. Overloading and off-centre loading both trip the load-sensing system on newer machines under ANSI A92.20, which means the lift refuses to elevate; on older machines nothing stops you, which is worse.
Prices for each class are in the rental cost guide. If you are pricing a job, list the class, the count and the weeks in a quote request and suppliers will confirm what they have on the yard.