Ordering GRP grating for an industrial project involves more than providing a panel size and choosing a colour.
The supplier needs enough information to understand what the grating will carry, how it will be supported, where it will be installed and what conditions it will face in service. Without that detail, important decisions around span, mesh, resin, surface finish, fixings and fabrication can be left until too late.
A clear GRP grating specification reduces that uncertainty.
Rather than treating grating as an isolated product, the specification should describe the duty it needs to perform within the wider platform, walkway, trench cover or access system.
The following checklist sets out the information that should normally be considered before an industrial GRP grating enquiry is issued.
1. Define where the GRP grating will be used
Start by describing the application.
The requirements for a process walkway may be different from those for a maintenance platform, stair landing, trench cover or removable access panel.
The specification should identify the purpose of each grating area rather than assuming every panel on the project performs the same role.
Typical applications may include:
- Pedestrian walkways
- Maintenance platforms
- Operating platforms
- Stair landings
- Trench and channel covers
- Drainage areas
- Removable equipment-access panels
- Access around tanks, machinery or process equipment
Where several applications occur on the same project, it can be useful to divide the grating into separate zones.
That makes it easier to apply different loading, mesh or surface requirements where necessary.
2. Record the required dimensions
Overall platform dimensions are useful, but they are not enough to manufacture a practical grating layout.
The supplier may also need:
- Finished area dimensions
- Individual panel dimensions
- Changes in level
- Irregular edges
- Curved or angled boundaries
- Openings for equipment or services
- Positions of supporting members
- Areas that need to remain removable
Where the grating is being fitted to an existing industrial structure, dimensions should be based on reliable site information.
Small differences between drawings and the installed structure can affect bearing, panel joints and openings.
If particular dimensions still need to be confirmed on site, the specification should make this clear rather than treating them as fixed.
3. State the design loading
The required load should be stated as part of the project information rather than left for the grating supplier to infer from the application.
A pedestrian route, for example, may also be exposed to maintenance equipment, temporary components or local point loads.
Where these are expected, they should be identified.
Relevant information may include:
- Imposed pedestrian loads
- Concentrated loads
- Maintenance loads
- Wheeled equipment
- Temporary equipment placed on the grating
- Any project-specific loading requirements
The loading needs to be considered alongside the actual support arrangement.
For the specification itself, the important point is that the required load is made clear before a panel type and depth are selected.
4. Confirm the clear span and support arrangement
Grating performance depends heavily on the distance between supports.
The clear span should therefore be established for each relevant area.
This is particularly important where the existing supporting structure is irregular or where different parts of a platform have different beam spacing.
The specification should identify, where known:
- Clear span
- Support centres
- Bearing width
- Support material
- Direction of supporting members
- Areas with cantilevers or interrupted support
For pultruded grating, the orientation of the main load-bearing bars is especially important.
Panel dimensions alone do not tell the supplier how the grating will behave once installed.
5. Decide whether moulded or pultruded grating is required
Moulded and pultruded GRP grating are not interchangeable products.
Each has structural and practical characteristics that may suit different applications.
The choice should therefore follow the project duty, support arrangement and required performance rather than being based simply on availability or panel thickness.
If the project specification already requires one type, state it clearly.
If the decision has not yet been made, provide enough information for the proposed system to be assessed against the actual application.
The grating specification itself does not need to repeat the full comparison. It needs to make clear which construction has been selected or which performance requirements the proposed product must satisfy.
6. Specify the mesh or aperture size
Mesh size affects far more than appearance.
The opening size can influence:
- Drainage
- Airflow
- Dropped-object risk
- Footwear suitability
- Movement of wheeled equipment
- Support for tools or smaller objects
- Cleaning requirements
A large open mesh may be useful in wet process areas where drainage is important.
A smaller aperture may be preferable where smaller objects could fall through or where the nature of the traffic requires a tighter surface.
The specification should therefore identify the required mesh arrangement rather than leaving it as an incidental product choice.
7. Describe the operating environment
The grating supplier needs to know what the product will be exposed to.
Simply specifying “industrial use” or “corrosive environment” may not provide enough information.
Relevant environmental details can include:
- Water and persistent moisture
- Wastewater exposure
- Salt-laden or marine atmospheres
- Process chemicals
- Cleaning chemicals
- Oils or other contaminants
- UV exposure
- Operating temperature
- Splash or washdown conditions
This information helps determine whether the proposed resin system and wider product construction are suitable.
Where chemical exposure is significant, the actual substances and conditions should be provided where available rather than relying on a general statement that GRP must be chemically resistant.
8. Identify any resin requirements
Resin selection can influence chemical resistance, fire performance and suitability for the operating environment.
Some projects will already specify a particular resin system.
Others will define performance requirements and allow the supplier or designer to propose a suitable product.
Either approach can work, provided the requirement is clear.
Where a particular resin type, client approval or performance classification is needed, it should be stated at enquiry stage.
This prevents a basic grating product being proposed and then rejected once the wider site requirements are reviewed.
9. State the required walking surface
Industrial grating needs to suit the conditions underfoot.
The specification should describe the expected surface conditions and any required anti-slip finish.
Consider whether the area is likely to be:
- Wet
- Oily
- Muddy
- Exposed to process residues
- Regularly washed down
- Used outdoors
- Subject to marine spray
A gritted or otherwise enhanced surface may be appropriate in demanding conditions, but surface finish should be selected alongside drainage and housekeeping arrangements.
Anti-slip treatment cannot compensate for poor platform drainage or standing contamination.
10. Include any fire-performance requirements
GRP should not be assumed to provide the same fire performance across every product.
Where fire behaviour is part of the project specification, state the relevant requirement clearly.
This might include a particular test method, classification or asset-owner requirement.
The supplier can then provide evidence for the proposed system.
This is preferable to requesting “fire-resistant GRP” without defining what performance needs to be demonstrated.
Any fire requirement should also be coordinated with the selected resin system.
11. Show every known opening and penetration
Pipework, cable routes, columns, valves and equipment supports can all interrupt a grating layout.
These openings should be shown before fabrication wherever possible.
For each penetration, useful information may include:
- Position
- Diameter or dimensions
- Required clearance
- Whether the service may move
- Whether insulation is present
- Whether access around the opening is required
Large openings may require additional supporting members rather than simply cutting a hole into a standard panel.
The support arrangement around penetrations should therefore be resolved alongside the grating layout.
Leaving significant cut-outs until site installation can create both structural and practical problems.
12. Identify removable grating panels
Some grating needs to be removed periodically to access equipment, channels or services below.
Those panels should be identified on the drawings and specification.
A removable panel may require a different approach to:
- Panel size
- Weight
- Fixing method
- Edge detailing
- Lifting
- Labelling or identification
It should also be possible to remove the intended panel without first dismantling unrelated parts of the access system.
Where a panel is expected to be lifted regularly, that should be stated. A panel removed once during a major shutdown may justify a different arrangement from one used for frequent inspection.
13. Define the fixing requirements
GRP grating needs to be properly restrained once installed.
The specification should identify any particular fixing requirements, including the material, type or frequency of fixings where these are defined by the project.
Fixing selection can be influenced by:
- Vibration
- Wind exposure
- Marine or chemical conditions
- Removable panels
- Supporting material
- Risk of unauthorised removal
The fixings need to suit both the grating and the structure beneath it.
A durable GRP panel can still create maintenance problems if clips and bolts are poorly matched to the environment.
14. State how cut edges should be finished
Industrial grating frequently requires cutting during fabrication.
The required treatment of cut edges should therefore form part of the specification.
Depending on the selected product and application, this may include appropriate finishing or sealing of exposed GRP edges.
Any requirements for banding, kerbs, toe plates or other perimeter details should also be identified.
This is particularly useful around openings and platform edges where grating interfaces with handrails or structural members.
15. Coordinate the grating with adjoining components
The grating does not exist independently from the rest of the access system.
Panel joints and supports may need to coordinate with:
- Handrail posts
- Toe boards
- Stairs
- Gates
- Structural profiles
- Equipment bases
- Adjacent flooring
- Existing steelwork
These interfaces should be considered before the grating layout is finalised.
A panel joint directly beneath an awkward handrail connection or a support member crossing an equipment-access opening may create unnecessary fabrication or installation problems.
Early coordination usually produces a cleaner panel arrangement.
16. Confirm site tolerances before fabrication
Existing industrial sites are rarely perfectly square or level.
Replacement grating and retrofit installations are particularly vulnerable to dimensional assumptions.
The project information should establish:
- Which dimensions have been surveyed
- Which dimensions require final verification
- Acceptable tolerances
- Who is responsible for confirming site information
- Whether adjustment is permitted during fabrication or installation
This is especially important where the grating needs to fit between existing steelwork, concrete channels, plant and pipework.
The specification should not force the installer to resolve significant dimensional discrepancies by uncontrolled site cutting.
17. Consider how the panels will reach the installation area
Panel size should be practical for the site as well as structurally efficient.
Large grating sections can reduce joints, but they may be difficult to move through an operating industrial facility.
Access restrictions may include:
- Doorways
- Existing platforms
- Stairways
- Pipework
- Restricted lifting areas
- Limited crane access
- Confined plant rooms
Where access is difficult, the preferred panel size may need to balance structural performance with handling and installation requirements.
This is worth establishing before the fabrication layout is approved.
18. Specify what documentation is required
The technical submission should match the complexity of the project.
Depending on the scope, the client may require:
- Fabrication drawings
- Panel schedules
- Load calculations
- Product data
- Material information
- Chemical-resistance information
- Fire-performance evidence
- Fixing details
- Installation information
- Inspection records
These requirements should be stated at enquiry stage.
Requesting additional evidence only after manufacture can create unnecessary delays, particularly where approval is required before installation.
A useful GRP grating enquiry should answer the important questions early
Before issuing a GRP grating specification, check whether it clearly states:
- Where the grating will be used
- What dimensions are required
- What loads need to be carried
- What the clear spans are
- How the panels will be supported
- Whether moulded or pultruded grating is required
- What mesh size is needed
- What environment the grating will face
- Whether a particular resin system is required
- What walking surface is needed
- Whether fire performance needs to be demonstrated
- Where openings and penetrations occur
- Which panels need to be removable
- What fixing arrangement is required
- How exposed edges should be treated
- Which site dimensions still need verification
- What installation constraints exist
- What technical documents need to be supplied
If those questions are answered, the supplier is in a far better position to propose GRP grating against a defined duty rather than making assumptions from a panel size alone.
For PJNC, grating specification forms part of the wider engineering process. The aim is to establish the loading, support, environment, fabrication requirements and site interfaces before manufacture so that the finished installation is appropriate for the industrial application.
A useful specification should remove uncertainty. It should tell the designer, fabricator and installer what the grating is expected to do and identify the areas that still require confirmation before the panels reach site.
FAQs About GRP Grating Specification
Can different GRP grating specifications be used on the same project?
Yes. Different areas may have different loading, environmental or operational requirements, so a single grating specification may not suit the whole site. Using clearly identified grating zones can help ensure the correct product is supplied for each application.
Should replacement GRP grating match the existing panels exactly?
Not automatically. The existing panel size or appearance may provide useful information, but the current loading, support arrangement and site requirements should still be checked. Changes to the surrounding structure or use of the area may mean that a different specification is now appropriate.
Can GRP grating be supplied in colours other than the existing installation?
Colour options depend on the selected GRP product and resin system. Where colour is important for asset identification, visual contrast or client requirements, it should be included in the specification rather than assumed to be available after the technical product has been selected.
Should spare GRP grating panels be ordered with the original project?
Spare panels can be useful where an installation contains bespoke sizes or where rapid replacement is important to operations. Whether they are worthwhile will depend on the scale of the installation, panel standardisation, storage arrangements and the consequences of a damaged panel remaining out of service.
How should changes to an approved GRP grating specification be managed?
Changes that could affect panel type, dimensions, support conditions or required performance should be reviewed by the appropriate project team before manufacture or installation proceeds. Recording approved revisions also helps ensure drawings, schedules and supplied panels remain consistent.