What is Floor Load & How Do Scissor Lift Brands Stack Up?

07/23/2021

The increased demand for efficiency from contractors and jobsite planners as well as the spread of sensitive flooring materials like computer flooring has brought floor load into the spotlight. Many construction sites now call for machines that produce less strain and prevent damage to the floor or building structure. But what exactly is floor load, and how do the different scissor lift brands compare?

What is Floor Load?

Floor load, or ground pressure, is the amount of force a floor can withstand, or the amount of pressure a machine exerts. If the pressure exerted by a scissor lift or any other piece of equipment exceeds the capacity of the floor beneath it, damage can be done to the floor or to the building’s structure. Naturally, when we think of pressure our first thought goes to the weight of the machine, but this is not the only factor at play. Platform capacity, gross machine area, occupied floor area, and wheel contact area must also be considered to get an accurate idea of how much strain the machine is exerting. Let’s run through those terms quickly.

Platform capacity: The amount of external weight added onto the platform.

Gross machine weight: The total weight of the machine plus the weight of anything on the platform. The minimum value would be the same as the machine weight if it is empty. The maximum value would be the weight of the machine plus the platform capacity.

Occupied floor area: The estimated floor space occupied by the machine base. Calculating this value is simply the length of the chassis multiplied by the width of the chassis.

Wheel contact area: The area that the lift’s wheels are in contact with the floor. Remember to multiply the value of an individual tire times four to get the value for all four wheels.

Maximum Machine Load vs. Maximum Wheel Load

When determining whether a lift is safe to drive on a specific surface, you must consider both the machine load and the wheel load. These measurements are similar but vary in what parts of the structure they will impact.

Maximum machine load is the upper limit to how much weight a surface can support. If this value is exceeded, it can damage the building’s structure, such as beams and concrete, as the floor will not be able to support the weight of the machine. Machine load is measured in pounds per square foot, or PSF.

Maximum wheel load focuses on the individual wheels rather than the whole machine. When lift platforms are loaded, the added weight does not distribute equally, causing the four tires to each exert a different amount of pressure on the floor. So, while the machine’s total weight may be lower than the floor’s requirements, depending on how the platform weight is distributed, the lift may still exceed the maximum wheel load. If this were to occur, the pressure could cause cracks or punctures to the floor’s surface. This is especially important on more sensitive materials like tiles, carpet, or wood. While the force being quantified is the same, wheel load is measured in pounds per square inch, or PSI.

Calculating Machine Load

We’ve run through all of the important terms and concepts to calculate machine load, now we can put them all together and do the math. Machine load is determined by taking the gross machine weight divided by the occupied floor area. An expanded formula would look like this:

(Machine weight + occupied platform capacity) / (chassis length * chassis width)

Machine Loads by Brand

We’ve established why machine load matters and how it’s calculated. Now, let’s compare the machine loads of leading scissor lift brands. The lower the machine load, the less strain each individual lift is putting on the floor, allowing for more workers on the surface. Featured in this table are 19 ft lifts from JLG, Genie, Haulotte, Skyjack, MEC, Snorkel, Sinoboom, and of course, Hy-Brid Lifts. For starters, we’ll compare these lifts with nothing on the platform, for the minimum gross machine weight.

The PS-1930 from Hy-Brid Lifts takes the crown with a PSF of 147.04. The S3219E from Snorkel is the only lift that could even crack 200 PSF, but just barely at 199.81, a full 52.77 extra pounds of force per square foot.

The next test adds in each lift’s maximum platform capacity to calculate maximum gross machine weight.

Well, what happened here? The PS-1930 still pulled out a victory, but the field closed in, with Snorkel taking second place at just 40 PSF greater. How did Hy-Brid Lifts lose its advantage?

The answer lies in platform capacities. Pro Series lifts, including the PS-1930, boast best-in-class lift capacities. Its 650 lbs is far greater than any competitors, with Skyjack collecting a silver medal at only 600 lbs. Many of the lifts in this category max out around 500 lbs with JLG, Genie, Sinoboom, Haulotte, and MEC all at 507 lbs or lower. The lower capacity does reduce floor load but does so at the expense of lift performance. Even then, they still can’t stack up to the PS-1930.

To level the playing field, Table 3 gives all machines the same platform load at 500 lbs. Unsurprisingly, Hy-Brid Lifts is still on top, followed by Skyjack, MEC, Haulotte, Genie, JLG, Sinoboom, and finally Snorkel. Best-in-class floor load and industry-leading platform capacity may feel too good to be true, but the PS-1930 gives operators both.

The gap between Hy-Brid Lifts and the field is simply enormous. Snorkel still sits in second place at 232.29 PSF, but the gap between the S3219E and the PS-1930 is a whopping 48.22 PSF, which is greater than the gap between Snorkel in second and Sinoboom in last at 266.55 PSF. All other competitors fall in this 34.26 PSF range, while the PS-1930 remains in a class of its own. At maximum platform capactiy, the PS-1930 still has a lower floor load than an empty S3219E!