All pipes and fittings should be inspected before installation at the job site to ensure that no damage has occurred during transit or storage.
If any damage has occurred, it is possible to repair a GRP (Glass Reinforced Plastic) pipe, but the repair method depends on the extent and type of damage.
Typical Situations Where Repairs Are Possible
Minor surface damage: Scratches, gouges, or superficial cracks can usually be repaired with resin and glass matting (laminate patching).
Leaks at joints: Can often be fixed by resealing or re-bonding the joint.
Small holes or pinholes: Repaired by grinding out the damaged area and applying a new laminate layer.
Localized cracks: Can be cut out and reinforced with new GRP laminate.
Common GRP Pipe Repair Methods
Laminate Repair (Patch Repair)
Damaged area is cut back to sound material.
Surface is abraded, cleaned, and dried.
Layers of resin-impregnated fiberglass are applied and cured.
Sanded and coated for corrosion protection.
Section Replacement
If the pipe has a long crack or severe structural damage, the affected section is cut out.
A new GRP pipe section is joined in using couplings or laminated joints.
Sleeve or Overlay Repair
A GRP sleeve (internal or external) is fitted over the damaged area.
Bonded with resin for reinforcement and leak sealing.
Joint Reinstallation
If leakage occurs at couplings, it may require disassembly and reinstallation with new seals or joint replacement.
⚠️ When Replacement is Better
If the damage is extensive (e.g., long cracks, delamination, severe impact damage).
If the pipe has been compromised structurally and cannot guarantee long-term pressure integrity.
If the system is critical (e.g., high-pressure or chemical service), replacement may be safer.