FRP grating load tables help you determine whether a grating panel can support the expected load without excessive bending. However, the highest number in the table is not automatically the correct load capacity for your project.
To read the table correctly, you must match the exact grating type, panel thickness, support span, load type, and allowable deflection. Using data from a different product series or support arrangement can result in an unsuitable selection.
A load table shows how a specific FRP grating configuration behaves under different loads and support spans. Manufacturers may provide separate tables for molded grating, pultruded grating, pedestrian grating, and high-load products.
Depending on the manufacturer, the table may include:
Always confirm that the table belongs to the exact product being specified.
Before reading the load values, first identify whether the product is molded or pultruded FRP grating because their reinforcement patterns and load behaviour are different. Molded grating has reinforcement running in two directions, allowing loads to be distributed across the panel. Its load table usually shows the relationship between panel depth, mesh configuration, support span, applied load, and deflection.
Pultruded grating uses parallel bearing bars that carry most of the load in one direction. The bearing bars must be positioned across the supporting beams, so the installation direction is essential. Because the two products have different structures, a molded grating load table should not be used to assess pultruded grating, and vice versa.
The next step is identifying the correct panel configuration. Do not read values from a row simply because the overall panel dimensions appear similar.
The product description may include information such as:
A deeper panel generally provides greater stiffness, but depth alone does not determine capacity. Mesh arrangement, reinforcement, resin system, and manufacturing method also affect performance.
The clear support span is the unsupported distance between the edges of two supporting beams. It is not necessarily the full panel length or the centre-to-centre distance between supports.
For example, a 1,200 mm panel may rest on supports with only 900 mm of clear space between them. In that case, you should use the 900 mm span row in the load table.
Support span has a major effect on deflection. As the unsupported distance increases, the same grating panel will bend more under the same load. Manufacturer tables therefore provide different results for each span.
FRP grating load tables normally separate loads according to how they are applied. Using the wrong load category can produce an incorrect result.
A uniform load is distributed across the grating surface. Examples include groups of pedestrians, stored materials distributed over a platform, or general floor loading.
Uniform loads may be expressed in:
A line load is applied across a narrow line over part or all of the panel width. It may represent certain equipment bases, wheels, or a load distributed through a narrow support.
Some manufacturer tables express concentrated line loads in pounds per foot of grating width.
A point load acts on a small area, usually near the centre of the unsupported span. Examples may include an equipment foot, trolley wheel, or maintenance load.
Point-load values are normally expressed as a total force rather than a load per square metre. A panel that performs well under a uniform load may show greater local deflection under a concentrated point load.
Deflection is the amount the grating bends under an applied load. It is usually measured at the centre of the unsupported span.
A grating panel may remain below its failure load but still bend too much for comfortable or safe use. For this reason, deflection often governs the final selection.
Deflection for pedestrian grating is often limited to approximately 6 mm to maintain user comfort. Deflection above approximately 12 mm should be avoided because excessive movement may place additional force on hold-down clips and cause fasteners to loosen. These figures are general references, so the allowable deflection must still follow the project specification and product-specific load table.
Use this process when reviewing a load table:
Assume a pedestrian platform uses a grating panel supported over a clear span of 900 mm. The expected uniform load is 4 kN/m², and the project allows a maximum deflection of 6 mm.
In the relevant manufacturer’s table, find:
Item
Project Requirement
Grating type
Exact specified product
Clear span
900 mm
Load type
Uniform load
Design load
4 kN/m²
Maximum deflection
6 mm
The selected panel is potentially suitable only when the table shows a deflection of 6 mm or less at that load and span. You must then confirm that the load remains below the manufacturer’s recommended limit.
This example is illustrative and should not replace product-specific engineering data.
Some load tables show both an ultimate capacity and a maximum recommended load. They are not the same.
Ultimate capacity indicates the load associated with structural failure during testing. Maximum recommended load applies a safety factor and represents the lower value intended for selection.
For example, Strongwell’s pultruded grating tables identify recommended loads using a 2-to-1 safety factor. That safety factor belongs to the specific published table and should not automatically be assumed for every manufacturer or product.
Never specify grating based on the failure load.
A load table usually assumes particular support and loading conditions. Actual performance may change when the installation includes:
Additional framing may be required around pipes, access openings, equipment, and irregular panel edges. Hold-down clips and panel connectors must also follow the approved installation arrangement.
At GAJA Fiberglass, we manufacture Dura Gritz® molded FRP grating using thermosetting resin and high-strength roving reinforcement. The product is used for platform decking, walkways, trench covers, chemical-processing areas, and other industrial access applications.
Our product information states a high loading capacity of up to 750 kg. However, we do not treat this figure as a universal allowable load for every installation. Before confirming a configuration, our team reviews the panel depth, clear span, load type, supporting frame, cutting layout, chemical exposure, and required deflection limit.
Reading a load table correctly helps prevent excessive deflection, unsuitable panel selection, and problems during installation. The final configuration should be based on the actual load, clear span, support layout, chemical environment, and project specifications.
Our team can review these details before preparing a suitable Dura Gritz® FRP Grating configuration.
Indonesia Head OfficeEmail: marketing@gajafiberglass.comPhone: +62 (21) 4585-3491WhatsApp: +62 811-186-7919
Australia RepresentativeContact Person: Mr. Victor BhaveEmail: victor.bhave@gajafiberglass.comPhone: +61 41 424-0017
The load, support span, and deflection must be read together. One value cannot be evaluated independently.
A thicker panel is generally stiffer, but capacity also depends on the mesh, reinforcement, support span, and product design.
It is the unsupported distance between the inside edges of two supporting members.
No. A uniform load is spread across the panel, while a point load is concentrated within a small area.
No. Use the table issued for the exact manufacturer, product series, panel configuration, and resin system being supplied.
