Design & specification
Grating Load and Deflection Basics
Load capacity and acceptable walking performance are related but different checks. A panel can remain strong while deflecting more than the project allows.
Do not compare two products until their tables use the same load type, span definition, support condition, units and deflection criterion.
Separate the load cases
Uniform load is distributed over an area. Concentrated load acts over a defined footprint, while a wheel load depends on wheel contact, position and distribution. These cases are not interchangeable, and a pedestrian table should not be used to approve vehicular service.
| Load input | Question to resolve |
|---|---|
| Uniform | What design pressure and loaded area apply? |
| Concentrated | What force, footprint and critical position apply? |
| Wheel | What wheel load, contact area and traffic path apply? |
| Dynamic | What impact or vibration allowance does the design basis require? |
Read every table condition
Confirm material, bearing-bar size, pitch, span, restraint, units, load definition and whether the published value is strength-limited, deflection-limited or both. NAAMM identifies separate manuals for regular and heavy-duty grating, which is a useful warning against treating all tables as one dataset.
Deflection is a serviceability decision
The project specification should state the acceptable deflection or performance criterion. Comfort, alignment with adjacent flooring, drainage and equipment operation may control before ultimate strength. Do not invent a universal deflection limit where the governing code or project standard has not supplied one.
Use the calculator as a screening aid
GoGrating's calculator and load tables can support preliminary selection, but final acceptance requires project-specific engineering and product data. Record all assumptions so a reviewer can reproduce the comparison.
Primary references
Checked 2026-09-03. Verify the edition accepted by your project before use.