How do stair lifts work?

How stair lifts work

“Stair lifts operate by navigating a metal rail,” Shane Campbell, business development manager at stair lift dealer Options HME, explained. “The [stair lift’s] chassis houses rollers that align the lift to the rail, and an electric motor provides the power to move the lift up and down.”

The journey on a stair lift involves four steps:

1. Prepare: Unfold the seat, armrests and footrest.
2. Board: Sit on the chair and secure the seat belt.
3. Operate: Press and hold the control switch in the direction of travel.
4. Dismount: At the journey’s end, swivel the seat toward the landing before standing.

Operating a home stair lift

Using a stair lift is straightforward, even for those with limited dexterity. “Most lifts use a large toggle switch or joystick on the armrest to control the movement … so users with limited hand function can use a wrist or forearm,” Campbell said. The lift moves at a safe, controlled pace of less than one foot per second.

Most stair lifts cost $2,000 to $15,000

For added convenience, many of the top stair lift companies provide remote controls. According to Celestina Roberts, marketing manager at Stannah Stairlifts, these are sometimes mounted to the wall or placed in a handheld remote. This lets you call the lift to you from the top or bottom of the stairs, she explained.

Stair lift driving mechanisms

The driving mechanism inside modern stair lifts typically uses one of two systems:

• Rack and pinion drives: Roberts described these as using a “toothed track, much like clockwork gears, that rotate to move the stair lift chair up or down the stairs.”
• Cable/chain drives: Less common today, Roberts said these systems use a powered cable or chain to pull up or lower the stair lift.

Components of a stair lift

Stair lift components may differ across manufacturers and models. But generally, you can expect more types of stair lifts to include these essential parts:

• Rail: This is the foundation of the system — it attaches to the stair treads. Manufacturers use aluminum for most straight stair lifts and often choose stainless steel for curved models.
• Drive system: According to Campbell, most modern lifts use a rack and pinion system where a toothed gear engages with tracks inside the rail.
• Motor: This is a bidirectional electric motor that powers the whole system.
• Seat/backrest: Most models have foldable seats, armrests and footrests that you can tuck away when not in use. Swivel seat functions allow for safer entry and exit by letting you turn away from the stairs.
• Battery system: “Your fully charged battery-powered stair lift can take you up and down the stairs about 10 to 20 times, depending on your set-up,” Roberts pointed out.

Safety features of stair lifts

“Stair lifts are designed to move users securely,” Roberts said. Manufacturers build multiple layers of protection into every unit to prevent accidents — especially crucial given that users often have mobility challenges. Here are the main safety features:

• Seat belts: “Seat belts on most stair lifts are similar to an automotive lap belt,” explained Campbell. “Some lifts have an optional harness that provides securement of the upper body for users with limited trunk stability.” These restraints keep you secure, especially on steeper staircases.
• Obstruction sensors: “[These are] commonly on the sides of the footrest and the upper and lower part of the motor housing,” Campbell highlighted. If they contact an object, the lift will stop and only allow travel in the opposite direction until you clear the obstruction.
• Swivel seats: This feature allows safer dismounting. “By rotating the seat, you aren’t dismounting from the stair lift on a stair or facing the staircase,” Roberts pointed out. Instead, you exit facing the landing with the chair as support. Most models rotate 45 to 90 degrees toward the landing and lock in place.
• Overspeed governor: “[If] the lift starts to [move] in an uncontrolled fashion, the overspeed governor will engage and bring the lift to a stop,” noted Campbell. Roberts adds that this safety system uses centrifugal force to sense the stair lift’s speed and works even without power.
• Limit switches: Located at the rail ends, these automatically stop the stair lift at the correct position, preventing it from traveling off the track.

Powering a stair lift

The majority of modern stair lifts run on battery power for safety and reliability. They rely on two 12-volt batteries connected to deliver 24 volts of power to the motor, which ensures consistent operation.

How stair lift batteries work

Stair lift batteries charge through what Roberts calls “trickle charging.” The system uses charging contacts located at the top and bottom of the rail. When you park the chair at either end, it automatically recharges. Campbell notes that the charger plugs into the rail rather than the motor housing.

During power outages, battery-powered models continue working without interruption, according to Campbell. You can use the lift without flipping any special switches. This feature is crucial during emergencies, especially when you need to reach a basement shelter during severe weather.

Author’s note

Most new stair lifts include battery backup, but some basic models may not. Roberts cautions that directly-powered units will stop working during outages, potentially leaving you stranded on the stairs. Since this poses serious safety risks for people with mobility challenges, most experts recommend models with battery backup for peace of mind.

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Installation and maintenance

Campbell emphasized that stair lift installations are less invasive than many think. Professional installation follows a process that causes minimal disruption to your home:

1. Assessment: Installers measure your staircase and assess any unique features. “Your installation team will ensure the rail is level along the lateral length of the stairs and matches your stairs’ incline,” Roberts explained. This initial evaluation determines the correct rail length and mounting positions.
2. Rail preparation: Technicians cut the rail to fit your specific staircase. At this stage, Campbell noted they’ll also install the charging contacts and join the two pieces of rail to create a seamless track suited for your home’s architecture.
3. Mounting: For standard straight stairways, Campbell explained that four brackets typically hold the rail in place: one at the bottom step, one at the top and two in the middle. These attach with lag bolts and work with carpet, hardwood or concrete steps.
4. Assembly: “[The final step involves] setting the seat level, positioning the rail, verifying the lift’s operation and providing instruction,” Campbell said. This ensures everything works well and you understand how to use your stair lift.

Can you install a stair lift yourself?

It’s best to get a stair lift professionally installed unless you’re a trained stair lift engineer. Stair lifts require precise measurements, secure mounting to stairs and electrical connections that most homeowners aren’t equipped to handle.

“A trained stair lift installation professional knows how to [properly] space brackets, align gears and calibrate safety sensors,” Roberts pointed out. Campbell warned that improper installation can lead to user injury or breakdown of the lift through issues such as loose belts or misaligned rails.

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Post-installation maintenance tips

After installation, your stair lift will need basic upkeep. Campbell recommended the following three key maintenance practices:

• Keep the rail clean of dust and pet hair.
• If your model requires greasing, apply it at the recommended intervals (usually every six months).
• Replace the batteries every three to four years before they start showing signs of weakness.