Calculating Floor Load Capacity for Your Business

Need to calculate your floor load capacity for your commercial building? There are a few steps and calculations for the process. First, you want to learn about your community’s building code requirements. In some circumstances, you might want to leave the job to a structural engineer. However, there are some measurements and tables you can use for your floor load capacity calculator. With these few suggestions, you can estimate the load limits of your commercial kitchen flooring


What Is Floor Load Capacity?

If you are redesigning your business space, you need to understand the floor load capacity. This calculation is the total weight that a floor can support over a specific area. In the United States, this measurement is expressed as pounds per square foot (psf). Your floors should be engineered to handle live and dead loads. With these calculations, you will know the weight limits of your particular space. 


Why You Need To Know Your Floor Capacity

It is vital to have a floor load capacity calculator for a variety of reasons. In a commercial space, you might need to install heavy equipment as part of your business. You don’t want those pieces to break or buckle your floors, as both will increase maintenance costs. For that reason, the floor load capacity determines the weight limits of that space. 


Different Types of Loads

You might think that there is a single type of load to take into consideration for your business. However, there are two different kinds of weight loads: live loads and dead loads. A live load is the weight of the people, equipment, and other furnishings that your floor needs to support. Anything that isn’t attached to the floor is considered a live load. 

Anything that is permanently attached to the floor is considered a dead load. This type of load can also include the material that is used in the floor’s construction process. For example, if you have a wooden floor that is covered with vinyl or carpet, you have to calculate the weight of those materials per square foot. With all those heavy flooring materials, the extra weight increases your dead load. 


Know Your Building Codes

No matter where you live, you need keep your building up-to-date and abide by local building codes. Many of these codes have a minimal live load that all floors must be able to handle. Most building codes are based on the International Residential Code (IRC). 

Following these specifications, all floors in those non-sleeping rooms have a minimal live load of 40 pounds per square foot. Any sleeping rooms must be able to support a live load of 30 pounds per square foot. 

There is a measurement called the deflection limit. With that calculation, these IRC codes determine how much the floor can bend under a heavy load. According to the IRC, floors must not deflect more than 1/360 of the span of the floor. If you have a floor with a span of 10 feet, then it has a deflection limit of 120 inches. 


Understanding Span Tables

Span tables determine the design limit for a specific lumber type. The table allows you to calculate whether your design meets those code requirements. If you use a particular spacing and joist size, the table indicates its strength value. This value is known as the Fb value. Another value to remember is the E value. That value takes in the stiffness of the floor joist. 

Most engineers and architects utilized these tables to determine the spacing and size of the joists. When they design the building, they use these calculations in their plans.

How do these values and tables work for you? If you have measurements for your space, you might want to work backward to calculate your floor’s load capacity. 


How To Determine Your Floor Capacity 

There are a few measurements and values to add to your floor load capacity calculator. You want to determine the spacing, span, and size of your floor. The lumber grade and species of your floor joists are also vital information to know. If you need to find the grade and species, look for a stamp on the lumber. 

Now that you have your values, you will want to use a span table. With these calculations, you can find the Fb value of your joists. For example, if you have a space of 10 feet by 11 feet with a 2×6 Douglas fir joist, the value determines that your joists have an E value of 1,900,000 and an Fb value of 1,495.

After you have consulted the span table, find the required Fb value of your specific table. Suppose your joist has a span of 11 feet and 2 inches with a spacing of 16 inches. With that measurement, the span table will have a 30 psf live load and 10 psf dead load floor. 

You can determine that the Fb value is 1,315 with an E value of 1,800,000. In other words, your floor joints will be able to support a 10 psf dead load and 30 psf live load. You can also use a span table for calculating floor load. Make sure to scan the table until you find the heaviest limits for your particular floor. 

For instance, if you have a 40 psf live load and 10 psf dead load, your floor has an E value of 2,400,000 and an Fb value of 1,644. In simple words, all your existing joists will not be able to support a live load heavier than 40 psf. 

Once you have determined all the load limits of your joists, you need to calculate the acceptable capacity for your commercial business. It is vital to calculate the correct weight limits for your floors. Without verifying load limits, your equipment or furnishings could cause issues with the joists. These load limits keep your business and customers safe from bucking floors.