GRP Technical Guide

A Comprehensive Technical Guide for Engineers, Designers and Specifiers

GRP pultrusion has moved from a niche alternative to a specified structural material across rail, water, nuclear, marine, defence and chemical processing infrastructure throughout the UK. Yet for many structural engineers it remains unfamiliar territory, and that knowledge gap has been the single greatest barrier to wider adoption.

Written by Gavin Williams, Managing Director of Engineered Composites Ltd, this guide draws on decades of hands-on manufacturing experience and thousands of real GRP projects to give engineers, designers and specifiers the working knowledge they need to specify GRP pultruded products with confidence.

The guide is structured in four parts, moving from fundamentals through to future technology.

Part I covers material science, manufacturing, design principles and product range, giving engineers new to GRP the grounding they need before moving into design work.

Part II addresses UK standards, specifications and detailed structural design, including extensive worked examples for structural members and connections.

Part III examines real-world application through platforms and walkways, handrail systems, fencing and barriers, specification and procurement, installation and inspection and maintenance guidance.

Part IV looks at emerging technologies including self-healing resins, embedded sensors and smart infrastructure, reflecting that GRP is a material still evolving rather than standing still.

Extensive appendices provide standard profile dimensions, characteristic material properties, chemical resistance data, connection details, fire performance data, environmental impact data, cost comparison methodology and sector-specific guidance for rail, water, highways, nuclear and defence applications.

This book is written for structural engineers, designers and specifiers who need to make confident, well-informed material decisions. It is equally valuable as an introduction for those approaching GRP for the first time and as a reference for experienced professionals who need fast access to property data, design methodology and standards guidance.

Property values and design methods throughout represent current best practice and typical performance from quality manufacturers, always cross-referenced against the standards that govern UK specification. The result is a reference that bridges the gap between GRP’s proven track record on demanding infrastructure projects and the confidence engineers need to specify it correctly.

This guide is intended to supplement, not replace, the expertise of qualified structural engineers. All structural designs must be carried out by suitably qualified professionals in accordance with applicable codes, standards and regulations.

First Edition, 2025. Written by Gavin Williams, Managing Director, Engineered Composites Ltd, Chester, United Kingdom.