GRP Riser Flooring – What is it and how do I install?

Riser flooring is an integral part of any high-rise build project, in order to provide fall protection and improve the safety of workers. Read on to discover different methods of installation and which is best for different project types.

What is GRP Riser Flooring? 

Within a high-rise building, there are shafts that run from top to bottom where electrical services, water pipes and HVAC systems are housed. This allows heating, water and electricity to be easily distributed to each floor, whilst keeping them hidden. Often there will be wet and dry risers within a building, which are used in the event of a fire. Dry risers are empty shafts where the fire rescue services pump water throughout the building from the bottom. Wet risers already have water systems in that can be controlled to extinguish a fire. However, these riser shafts can present a health and safety hazard to those who access them, as a fall from height could be fatal. The common practice is to install a ‘riser floor’ at each level where the riser is accessible. Grating is a popular choice as it allows visibility up and down the riser shaft. However traditional grating, such as steel, poses a risk due to the high levels of voltage stored in these risers, so glass reinforced plastic (GRP) grating is the solution, thanks to its non-conductive properties.

How do I install GridEX® GRP Riser Flooring?


With new build projects, if the riser flooring is considered early on in the project, it can be installed at each level as the build progresses. Casting the GRP in the concrete removes the need for any mechanical fixings.

Concrete Rebate

However, it is often the case that the riser flooring is not considered until the concrete has been poured. A rebate is the most seamless way to fix Waux GRP riser flooring, in this instance, although it can also be placed on top of the concrete or steel frame if necessary. Waux M Clips hold the grating fast while concrete anchors secure it.            

GRP Angle Frame

If it is not possible to cast in, for example during a refurb project, GridEX® GRP Grating can be easily retrofitted. GRP angles can be cut to size in our workshop, or are easy to cut-in on site and fix to the inside of the riser shaft to form a shelf.

With larger voids, GRP angle beams will be needed in any case so that the load can be supported.


Benefits of using GRP as Riser Gratings
  • Non-conductive, so no risk around electrical circuits
  • Easy to cut in on site to accommodate awkward corners, and does not spark when cut
  • Lightweight, can be manually manoeuvred in where required
Waux recommends that no more than a 20mm gap is left around service pipes passing through the floor, as this can impact the structural integrity of the GridEX® GRP Grating.  Read our overview article to discover all the benefits of GRP!


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