How to Specify 4×8 Molded Fiberglass Grating Panels

Quick answer: Unicomposite’s current FRP grating catalog lists two molded grating configurations at 4 × 8 ft (1220 × 2440 mm): 1.0 in (25 mm) and 1.5 in (38 mm) thick. Both rows list a 1.5 × 1.5 in (38 × 38 mm) mesh designation and 70% open area. The footprint identifies a cataloged panel size; it does not by itself establish allowable load, support span or current availability.

What Does “4×8 Fiberglass Grating” Mean?

In a purchasing inquiry, 4×8 fiberglass grating normally identifies the nominal full-panel footprint. In the current Unicomposite catalog, the corresponding listed metric panel size is 1220 × 2440 mm.

That footprint is only one part of the specification. Two panels can share the same length and width while differing in thickness, panel weight, resin request, surface request, and suitability for a particular support and load condition. A useful quotation request therefore identifies the catalog configuration and the project conditions separately.

Current Cataloged 4×8 Molded Grating Configurations

The following values are transcribed from the current customer-facing Unicomposite FRP Gratings Product Catalog. Values and paired units are reproduced as listed so that buyers can refer to the same fields during an inquiry.

Specification field	25 mm catalog row	38 mm catalog row
Catalog panel size	4 × 8 ft (1220 × 2440 mm)	4 × 8 ft (1220 × 2440 mm)
Panel thickness	1.0 in (25 mm)	1.5 in (38 mm)
Catalog mesh designation	1.5 × 1.5 in (38 × 38 mm)	1.5 × 1.5 in (38 × 38 mm)
Bar thickness	1/4 in (6.4 mm)	1/4 in (6.4 mm)
Open area	70%	70%
Catalog areal weight	2.4 lb/ft² (11.6 kg/m²)	3.8 lb/ft² (18.4 kg/m²)
Catalog full-panel weight	77 lb (35 kg)	121 lb (55 kg)

How to read the listed units: The dimensions above use the unit pairs printed in the catalog. They should not be treated as exact mathematical conversions or manufacturing tolerances. When fit is critical, use the dimensions and tolerances confirmed in the quotation and approved drawing.

How to read the listed weights: The catalog lists areal weight and full-panel weight separately. Multiplying a displayed areal value by the nominal panel area may not reproduce the listed full-panel weight exactly. Use the full-panel value as listed for catalog comparison, and confirm the quoted configuration when shipping or handling depends on weight.

This table confirms two cataloged molded-grating configurations with the requested 4 × 8 ft footprint. It is not a load or span table, and it does not mean every resin, surface, color, inventory status, fabrication option, or delivery schedule is available for both rows.

How Much Area Does a 4×8 Panel Represent?

A nominal 4 × 8 ft panel has a 32 ft² plan footprint. The 70% open-area value describes openings within that footprint; it does not reduce the nominal panel footprint to 70%.

Dividing a project area by 32 can support an initial full-panel estimate, but it does not establish the final order quantity. Finished-piece layout, openings, edge details, support locations and cutting allowances can all affect the number of panels required. Use a dimensioned layout when the purchase depends on actual cut-piece yield.

What the 4×8 Label Does Not Tell You

A footprint-only request leaves several purchasing questions unanswered:

• Supports and loads: The clear span, support arrangement, load case, load position and permitted deflection are separate from the panel footprint.
• Resin and surface: State the operating environment and requested surface instead of assuming that every combination is available for both catalog rows. Where an opening dimension or slip criterion matters, include the required measurement or test basis.
• Finished layout: A full panel may be divided into several finished pieces. Drawings should identify openings, cutouts, edges, bearing locations and required quantities.
• Acceptance documents: List the drawings, calculations, test records or other submittals required by the project. A catalog dimension alone does not confirm structural, fire, slip, electrical or regulatory acceptance.

Choosing Between the 25 mm and 38 mm Catalog Rows

The two catalog rows provide a useful starting point, but the choice should not be reduced to “thicker is always suitable.” Compare the exact quoted construction against the project’s clear span, supports, uniform or concentrated load case, load position and deflection limit using applicable approved data. Then confirm the requested resin, surface and acceptance documents for the operating environment. Thickness alone does not complete that review.

Mesh, Open Area and Panel Weight: What Buyers Can Confirm

Both cataloged 4×8 rows above list a 38 × 38 mm mesh designation, 6.4 mm bar thickness, and 70% open area. These are useful identity fields when comparing a quotation with the catalog. The table does not define whether the mesh figure is a clear opening, center spacing or another measurement basis. Request the dimensioned mesh drawing where opening size matters.

The 70% value belongs to the cataloged construction represented by these rows. Do not transfer it automatically to a covered or otherwise changed construction, and do not turn it into an unsupported statement about drainage rate, slip performance, heel safety, load capacity or code compliance.

The listed panel weights—77 lb (35 kg) and 121 lb (55 kg)—also help procurement and site teams plan receiving, movement, and staging. The figures do not replace a site-specific handling plan. Lifting method, staffing, access, packaging, panel condition, and local safety requirements still need to be addressed by the responsible project team.

4×8 Fiberglass Grating RFQ Checklist

For a more precise project discussion and quotation, submit the following information where available:

• The requested catalog row: 25 mm or 38 mm thickness, with the 4 × 8 ft (1220 × 2440 mm) panel size
• Number of full panels and, if applicable, a schedule of finished pieces
• Dimensioned drawings showing openings, cutouts, support lines, and bearing locations
• Clear span and support arrangement
• Uniform and/or concentrated load case, load position, and required deflection limit
• Operating environment, including media or chemicals, concentration, temperature, exposure frequency, UV exposure, and cleaning method
• Requested resin category, surface, and color, if specified by the project
• Required opening dimension and mesh measurement basis, where relevant
• Required documentation, submittals, test methods, and acceptance criteria
• Quantity, delivery destination, and requested project timing

If a field is not yet known, mark it as open instead of replacing it with an assumption. That makes the unresolved decision visible during quotation review.

Frequently Asked Questions

Does 4×8 describe the thickness or mesh size?

No. It identifies the nominal panel footprint. Thickness and mesh are separate specification fields. The current catalog lists both 25 mm and 38 mm thick molded configurations at 4 × 8 ft, and both rows list a 38 × 38 mm mesh designation.

Is a 4×8 panel exactly 1220 × 2440 mm?

The catalog pairs 4 × 8 ft with 1220 × 2440 mm as its listed panel size. These values should not be read as exact mathematical conversions or as manufacturing tolerances. Use the dimensions and tolerances confirmed in the quotation and approved drawing when fit is important.

Does the 38 mm panel automatically have a higher allowable load?

The catalog table on this page does not establish an allowable load. Selection requires the applicable load-and-deflection data for the exact configuration, together with the project’s span, supports, load case, load position, and deflection criterion.

Can I order every surface or resin option in both 4×8 configurations?

Availability should be confirmed for the selected catalog configuration. Do not assume that every possible surface, resin, color, fabrication service, inventory status, or lead time applies to both rows.

Prepare a Clear 4×8 Grating Inquiry

Review the Fiberglass Grating product range, then submit the preferred 4×8 catalog row together with your span, supports, loads, environment, finished dimensions, quantity, and required documents for project discussion and quotation.

Reference

1. Unicomposite, FRP Gratings Product Catalog, current customer-facing catalog; relevant molded-grating dimensional table on catalog page 11.