A scissor lift is a work platform that rises straight up on a folding crossed brace frame and does nothing else: it will not reach out sideways, which is what separates it from a boom. That vertical only movement is why it carries several workers and their materials where a boom carries one or two. Hire starts around $95 a day for the common 19 foot electric machine.
Straight up, and only straight up
The crossed steel braces underneath extend like a lattice, raising the deck on a vertical line above the machine's own footprint. There is no boom to swing over an obstacle, so the lift has to be driven to a spot directly beneath the work. That same constraint is why the deck is large enough for materials and more than one person.
The two families: slab and rough terrain
Electric slab machines run on solid tires and belong on level finished floors, indoors or on a poured slab. Rough terrain units are diesel or hybrid, with knobbly tires, a wider stance and outriggers on some models. The same platform height across those two families is a very different machine and a very different rate.
How high they go, and what that means at the deck
Machines are sold by platform height, and working height is usually quoted about six feet higher, because a person standing on the deck reaches that far. Common sizes on a lot are 19, 26, 32 and 40 feet of platform. Measure to the work, subtract what a person can reach, and then book, rather than taking the tallest available.
Guardrails are the fall protection, mostly
The platform is a guarded work surface, which is why a scissor lift falls under the scaffold rules rather than the aerial lift rules covering booms. The rails and a closed gate protect the occupant, standing on the rails is never acceptable, and an extension deck has to be pinned before anybody steps onto it.
Questions people ask about what is a scissor lift
What is a scissor lift used for?
Ceiling work, lighting, ductwork, drywall, signage, warehouse racking, and anything else directly overhead where a crew wants a stable deck instead of a ladder. It takes tools and materials up with the crew, which is what makes it faster than a ladder rather than merely safer.
Do I have to wear a harness in one?
In a scissor lift with intact guardrails and a closed gate, a harness is not generally required the way it is in a boom lift, where the platform can be thrown. The manufacturer's manual and the site rules can require one anyway, and many general contractors do.
Can it be used outdoors?
A slab machine cannot, beyond a level paved area, and wind ratings limit even that. Work on dirt, gravel or a slope calls for a rough terrain unit, which is the model yards stock for construction sites rather than for warehouses.
How much room does one need?
A 19 foot electric is roughly the footprint of a large desk and passes through a double door, which is why it is the indoor standard. Larger machines get wide quickly, and the honest limit is usually the doorway and the floor loading rather than the ceiling.