GRP for Water & Wastewater

The Swedish water and wastewater (WWT) sector faces major reinvestment needs. Many treatment works were built in the 1960s and 70s with grating, handrailing and structural steel — either galvanised or stainless — that are now corroding after decades of exposure to moisture, chemicals and hydrogen sulphide. GRP (Glass Reinforced Plastic) has emerged as the new standard for refurbishment and new build, because the material avoids the corrosion problems that define the industry.

Byggkomposit supplies GRP structures to municipal water companies, process contractors and consultants across Sweden. Typical projects include walkways over tanks, grating on grit chamber covers, handrailing around sludge wells, stairs to scraper bridges, platforms at inlet screens and access routes inside pumping stations and pressure boosting plants. The material is inert to most WWT chemicals, does not conduct electricity and is light enough that one or two technicians can swap a section during live operation.

Applications in water and wastewater plants

Treatment works and biological stages

On primary sedimentation, biological stages and secondary clarifiers, GRP grating is installed as walking surfaces above the open tanks. Because hydrogen sulphide (H₂S) and humid air attack both galvanic protection and stainless steel, fibreglass provides a fully corrosion-free solution that is also easy to jet-wash clean from sludge build-up.

Pumping and pressure boosting stations

Inside pumping stations, chemical exposure combines with electrical equipment. GRP handrailing and platforms are safe for personnel because the material does not conduct electricity, and combined with anti-slip surfaces they reduce the risk of falls in wet conditions. The structures are light enough to be lowered through existing manholes during refurbishment.

Waterworks and reservoirs

In waterworks producing drinking water, GRP is used for access routes around filter beds, UV systems and chemical dosing stages. Because the material does not release metal ions or microparticles, it complies with drinking water handling requirements. We supply certified grades for specific applications.

Refurbishment during live operation

One of the biggest advantages of GRP products in WWT projects is that they can be installed during live operation. With no hot works required and sections light enough to carry, staff can swap a grating panel in a few hours — instead of shutting down an entire treatment line for welding. That cuts both downtime and total project cost.