Ten Reasons to Choose GRP Over Steel For Construction

By Stuart Burns January 28, 2012

GRP GratingEveryone knows and understands steel in the construction world – it’s been used for hundreds of years and was invented thousands of years ago. And now there’s a new kid on the block – glass reinforced plastic (GRP)

GRP is well known in the boat-building, light aircraft and automotive industry. It’s lightweight, strong and non-corroding and can be moulded into intricate shapes and profiles. Its characteristics, performance, appearance and texture can all be designed-in to the manufacturing process.

How can this material work well in the traditional and conservative construction industry? And how does it stack up against traditional materials such as concrete and steel? Some of these advantages are outlined below.


GRP does not rust or corrode like steel and other metals. Nor does it suffer from the many chemical and corrosion failures of reinforced concrete. It’s impervious to water and gases and is widely chemical-resistant. The top surface characteristics can be defined to be capable of resisting the majority of caustic chemicals.

Reduced weight/density

GRP is approximately 60-75% less dense than steel, yet it has higher specific strength (or strength to weight ratio). The lower weight cuts handling, transport and installation costs. The top surface characteristics can be tuned to deliver the required resistance to point and line loads that match the underlying load-bearing characteristics to its operating environment.

 Low maintenance

As it doesn’t corrode, GRP doesn’t need any maintenance other than regular cleaning. Removable components are low weight and accurately manufactured for ease of lifting and replacement during cleaning. The material is UV stable to it doesn’t need any surface protection after installation either.

Elastic Properties

When steel reaches its elastic limit, it yields and deforms – GRP behaves differently and does not deform. It returns to its original shape after deflection, thanks to its advanced elastic properties. Tests have shown that GRP can resist significant impact loads very well without permanent deformation, saving costly repairs.

Cheaper to Install

As GRP is lower weight than steel strength for strength, installation is easier, often not requiring mechanical lifting equipment. This can save significant costs and time. Other savings can be made with transport, again thanks to the reduced weight. GRP does not require specialist cutting or welding equipment. Where required, joints are made using mechanical fixings secured with simple hand tools.


A GRP grating, with a carefully designed and integrally bonded gritted top surface, has achieved some of the highest levels of slip resistance ever recorded for a walking surface. GRP is 50% better than steel grating and 70% better than chequer plate for slip resistance. This safety margin advantage is crucial for high-risk working environments such as power stations, gas platforms and so on.

Non Static and Non Sparking

GRP is ideal for many hazardous environments, thanks to its static dissipative and non-sparking properties. Such hazardous environments include underground and offshore locations and those where flammable materials and gases exist. GRP won’t create a spark if normal tools are accidentally dropped – a hazard on steel flooring.

Temperature Resistance

GRP can withstand intense heat for long periods. Standard pultrusions can operate in continuous temperatures of 60-65°C with full structural integrity maintained, while vinyl ester and phenolic GRP pultrusions can withstand in excess of 100°C and 200°C respectively.

Electromagnetic Transparency

GRP does not attenuate the normal electromagnetic spectrum (e.g. radio waves) so it is very effective as a durable and strong material for radio masts and radomes.

Versatile Shape and Size

As GRP products are moulded in one way or another, it can be manufactured to the desired shape, design, performance, texture and finish to meet the specific needs. It’s a very versatile material that’s worth exploring. And if you come up with a new use for a structural composite, let us know!