GRP riser grating and standard GRP grating are made from the same general type of composite material, but the terms describe different applications.
Standard GRP grating is used across a wide range of industrial flooring, walkway and platform applications. GRP riser grating refers to grating that forms part of a flooring system specifically designed around a service riser.
The important difference is not that riser grating is installed vertically. The riser itself runs vertically through the building, while the grating is normally installed horizontally within it.
What Is Standard GRP Grating?
GRP grating is manufactured from glass fibre reinforcement and resin to form an open mesh panel.
It is commonly used to create flooring, walkways, platforms and access areas in industrial and commercial environments.
GRP is often specified because of characteristics including corrosion resistance, relatively low weight and electrical non-conductivity. Open mesh grating can also allow liquids and debris to pass through the flooring rather than collecting on the surface.
The appropriate grating specification depends on the application, including the required loads, clear span, support arrangement and environmental conditions.
What Is GRP Riser Grating?
GRP riser grating uses GRP flooring within service risers and similar building voids.
A service riser can contain pipework, ducting, cable trays and other mechanical and electrical services passing between different levels of a building. The flooring therefore needs to accommodate these services while providing suitable access within the riser.
Rather than simply placing a standard panel over an opening, the grating may need to be cut and fabricated around multiple service penetrations and installed onto an appropriate supporting structure.
GRP Riser Grating Is Not Vertical Grating
The term “riser grating” can cause some confusion.
A building service riser is a vertical space used to route services between floors. The GRP grating installed within that riser generally forms horizontal flooring at the required levels.
Its purpose is not to provide vertical access in the way that a ladder or staircase does. It provides a floor or working surface around the services within the riser.
Why Does a Service Riser Need a Different Approach?
A normal walkway or platform may have relatively straightforward panel dimensions and support positions. Service risers can be considerably more restricted.
The flooring may need to accommodate:
- Pipework
- Ducting
- Cable trays
- Electrical services
- Multiple service penetrations
- Existing steelwork and supports
- Restricted installation access
These factors influence how the panels are divided, cut, supported and installed.
Service Penetrations and Panel Layout
One of the main differences with a riser application is the number and position of services passing through the floor.
GRP panels can be cut to accommodate these penetrations, but the layout needs to be considered carefully. Openings around services, panel edges and support positions all form part of the overall flooring arrangement.
Accurate drawings and dimensions are therefore particularly useful when designing GRP flooring for a service riser.
Loads and Support Requirements
Being used within a service riser does not remove the normal structural considerations associated with GRP grating.
The required loads, clear spans and supporting structure still need to be established before the appropriate grating and support arrangement can be determined.
Depending on the riser, the flooring may be supported by existing structural steelwork or require additional support as part of the installation.
Panel thickness alone should not be used to determine whether a particular grating is suitable. Loads, spans and support conditions need to be considered together.
Access for Future Maintenance
Riser flooring also needs to take account of what happens after the building services have been installed.
Pipework, valves, cables and other equipment may need to be inspected, repaired, altered or replaced during the life of the building.
The panel arrangement should therefore provide suitable access without unnecessarily obstructing the services within the riser.
Standard GRP Grating vs GRP Riser Grating
| Consideration | Standard GRP Grating | GRP Riser Grating |
|---|---|---|
| Typical application | Walkways, platforms and industrial flooring | Flooring within service risers and building voids |
| Installation orientation | Normally horizontal | Normally horizontal within a vertical service riser |
| Service penetrations | Application dependent | Frequently designed around pipework, ducting and cables |
| Panel layout | Determined by the flooring or access area | Designed around the riser dimensions and service layout |
| Support | Designed for the required loads and spans | Designed for the required loads and spans within the available riser structure |
| Future access | Depends on the application | Needs to consider inspection and maintenance of building services |
Choosing GRP Grating for a Service Riser
The difference between standard GRP grating and GRP riser grating is therefore primarily about the application and the complete flooring arrangement rather than a completely different type of material.
A service riser introduces its own design considerations, particularly around service penetrations, available support, restricted access and future maintenance.
For a GRP riser flooring requirement, drawings showing the riser dimensions, service locations and available supporting structure provide a useful starting point for reviewing the proposed arrangement.