Fire performance should not be specified simply as “fire-rated GRP”.
That description does not explain what the material needs to achieve, which fire characteristic matters or what evidence should support the product being supplied.
An external maintenance platform may have different requirements from a walkway inside an enclosed process area or an access route used during an emergency. The specification therefore needs to start with the location and function of the access system, not with a resin type or product label.
Define the fire requirement first
“Fire performance” can refer to several different characteristics.
Depending on the application, the project may need to consider:
- Ignition
- Flame spread
- Smoke production
- Contribution to fire development
- Behaviour at elevated temperature
- Continued structural function
- Availability of an access or escape route
These are not interchangeable.
The first question should be what the GRP access system is expected to do if a fire occurs.
A route used occasionally for inspection may have a different requirement from a platform providing access to isolation equipment. An external walkway in an open area may also need different consideration from one inside an enclosed building.
The required outcome should be clear before the GRP product is selected.
Reaction to fire is different from fire resistance
This distinction is important when reviewing GRP products.
Reaction to fire concerns how a product contributes to the development of a fire. Depending on the test and classification system, this may include characteristics such as flame spread, heat release or smoke production.
Fire resistance concerns whether an element or assembly can maintain a required function for a stated period under defined fire exposure.
A product made using a fire-retardant resin should therefore not automatically be described as a fire-resisting structure.
A reaction-to-fire classification may provide useful evidence for the tested product, but it does not by itself confirm how an entire load-bearing platform, stair or walkway will behave during a fire.
Specifications should avoid vague terms such as “fireproof” where a more precise requirement can be stated.
Consider the function of the access system
The importance of fire performance depends partly on what the structure is used for.
An industrial GRP access system may provide:
- Routine operational access
- Inspection access
- Maintenance access
- Access to valves or isolation points
- A route between working levels
- Access associated with an emergency procedure
The consequence of losing that route can therefore vary considerably.
If the system performs an important emergency or operational function, that requirement needs to be identified during design rather than left for the material supplier to infer later.
Fire-retardant resin is only part of the specification
The resin system influences GRP fire behaviour, but specifying a resin family does not establish the performance of the finished access system.
Polyester, vinyl ester and specialist phenolic systems can provide different combinations of fire, chemical and environmental performance.
The correct choice depends on the complete operating environment.
For example, a platform in a chemical processing area may require both suitable fire performance and resistance to the substances present on site. One requirement should not be assessed without the other.
The choice between phenolic and polyester GRP grating should therefore be based on the actual project duty and supporting evidence rather than the resin name alone.
Check exactly what the fire evidence covers
Fire-performance evidence needs to relate to the product being proposed.
When reviewing test reports or classifications, check whether they apply to the actual:
- Product type
- Resin formulation
- Thickness or grating depth
- Construction
- Surface finish
- Mounting arrangement
- Intended application
Evidence for one GRP product should not automatically be applied to every product made from a similar resin.
For example, results for one grating construction may not support a different panel depth or configuration.
This matters when specifying both moulded GRP grating and pultruded GRP grating, because the finished products are constructed differently even where they are being considered for similar access duties.
The evidence should match the product closely enough to support the proposed use.
Surface finishes can affect the product being assessed
The finished component may include more than the underlying structural material.
GRP grating can incorporate:
- Gritted surfaces
- Surface veils
- Pigments
- Coatings
- Covered sections
Where fire-performance evidence is important, changes to the product build-up should not automatically be treated as cosmetic.
If a different surface treatment or product variant is proposed, the project team should check whether the existing evidence still applies.
The same principle applies to substitutions during procurement.
A similar-looking GRP product is not necessarily supported by the same test information.
Assess the complete access assembly
An access platform is not made from grating alone.
A complete system can include:
- Structural GRP profiles
- Grating
- Stair treads
- Stringers
- Handrails
- Toe plates
- Support brackets
- Fixings
- Connections to steel or concrete
Where fire performance is important, the specification needs to consider the function of the complete arrangement.
A grating panel may have suitable product evidence while questions remain about the supporting structure or the ability of the complete assembly to fulfil a particular requirement.
This is particularly relevant where continued structural performance at elevated temperature forms part of the project brief.
It does not mean every GRP structure requires a specialist fire assessment. The level of assessment should reflect the function of the route and the actual project requirement.
Establish the normal structural duty as well
Fire requirements do not replace normal structural design.
The access system must still be suitable for its everyday loading.
That may include:
- Pedestrian loads
- Concentrated loads
- Maintenance equipment
- Handrail loads
- Support spacing
- Deflection requirements
- Environmental loads where relevant
The loads acting on the GRP access system should be established separately from any fire-related requirement.
This avoids treating a fire classification as evidence of normal structural suitability.
Location affects the specification
The same GRP product will not necessarily be suitable for every industrial location.
Open external access
An external platform in an open environment may have relatively straightforward fire requirements, depending on nearby hazards and the function of the route.
Enclosed plant areas
Smoke, evacuation arrangements and nearby equipment may place greater importance on the selected product and supporting evidence.
Chemical and process plants
Fire requirements may need to be assessed alongside chemical exposure and access to important process or isolation equipment.
Marine and offshore sites
Restricted access, operational requirements and the nature of potential fire exposure may result in more specific project or client requirements.
The specification should reflect the actual installation rather than applying one standard material requirement across every part of a site.
Identify emergency and escape functions early
A GRP route that supports an emergency function needs particular attention during design.
This may include:
- Escape access
- Access to emergency equipment
- Access to isolation controls
- Firefighting access
- Other safety-critical routes
The GRP supplier should not be expected to determine this from drawings alone.
Where a route has an emergency function, it should be identified in the project information so that the material and structural requirements can be assessed against that duty.
Ask for evidence that answers the specification
A technical submission should make it possible to connect the proposed product with the evidence supplied for it.
Depending on the project, supporting information may include:
- Product data
- Test reports
- Classification documents
- Material information
- Relevant approvals
- Fabrication information
The key questions are straightforward:
- Which product was tested?
- What construction was assessed?
- Which fire characteristic was measured?
- Under what conditions?
- Does that evidence represent the proposed product?
A statement that a product is “fire retardant” does not answer those questions.
The supporting evidence needs to demonstrate the requirement actually stated in the project specification.
Avoid copying requirements from another project
A previous specification can be a useful reference, but its fire requirements should not automatically be transferred to another site.
A wastewater treatment platform, manufacturing plant, rail installation and offshore structure may all use GRP but operate under very different conditions.
Instead, establish:
- Where the system is installed
- What it is used for
- The relevant fire scenario
- Whether smoke or flame spread matters
- Whether continued structural function is required
- Which project or client requirements apply
The material can then be selected against those conditions.
This also reduces unnecessary over-specification.
The highest available product classification is not automatically the correct one if the project does not require it.
Record the requirement in the design information
Where fire performance is significant, it should be traceable through the design documentation.
Relevant information may include:
- Required fire performance
- Selected resin system
- Grating or structural profile type
- Approved product references
- Surface configuration
- Restrictions on substitution
- Supporting evidence
For bespoke systems, GRP fabrication drawings help connect the approved materials and components with the structure being manufactured.
This becomes particularly useful where different GRP products are used within the same platform, walkway or stair assembly.
Control substitutions and site changes
The installed system should remain consistent with the approved specification.
Changes that may require review include:
- Alternative grating products
- Different resin formulations
- Changed surface treatments
- Replacement structural profiles
- Additional cut-outs
- Unapproved coatings
A substituted product should be checked against the same fire requirement as the original product.
Changes should also be recorded so that the final installed system remains traceable.
This is especially important where the selected product formed part of a documented approval process.
Include fire requirements at the start of the GRP design
Fire performance is easier to manage when it is identified before product selection and fabrication begin.
Introducing a requirement late can lead to:
- Product substitutions
- Revised technical submissions
- Changes to drawings
- Procurement delays
- Rework
Fire requirements should therefore form part of the information used to design the GRP access system from the outset.
This allows material selection, structural duty and supporting evidence to be considered together.
Specify the requirement, not the description
The key question is not whether GRP can be described as fire resistant.
It is whether the proposed GRP system meets the fire requirement for that particular installation.
That means defining:
- The relevant fire characteristic
- The function of the route
- The installation environment
- The required supporting evidence
- Any need for continued structural performance
Once those points are clear, the resin, grating, structural components and documentation can be selected against a defined requirement.
That produces a much stronger specification than relying on broad terms such as “fire-rated GRP”.
FAQs About Fire Performance for Industrial GRP Access Systems
Can GRP fire performance change if a product formulation is updated?
Yes. Changes to resin formulation, additives, surface construction or manufacturing may affect whether older test evidence remains representative. Current product information should therefore be checked when fire performance is part of the specification.
Should fire-performance documents be retained after the GRP system is installed?
Yes. Relevant test reports, classifications, approved product information and final fabrication records can help future maintenance teams confirm what was originally specified when components need replacing or modifying.
Can replacement grating be selected only by matching its dimensions?
No. Where fire performance forms part of the project requirement, replacement grating should also be checked for the relevant material specification, construction and supporting fire-performance evidence rather than being selected solely because it fits the existing opening.
Does painting or coating GRP affect its documented fire performance?
It may. An additional coating changes the finished product build-up and should be checked against the basis of the available fire-performance evidence before it is applied to an installation with defined fire requirements.
Who should define the required fire performance for a GRP access route?
The requirement should come from the wider project design and fire strategy rather than being determined by the GRP supplier alone. The supplier can then propose products and evidence against the performance requirement provided.