The maintenance manual for a steel platform in a chemical plant runs to pages. Recoating schedules, surface preparation standards, coating inspection criteria, corrosion under insulation checks. The maintenance manual for an FRP platform in the same environment is a single sheet. FRP structures are low-maintenance, not zero-maintenance — the distinction matters because "zero maintenance" can lead to neglect, and neglect can turn a minor mechanical issue into a structural problem.
Inspection: What to Look For and When
FRP structures should be visually inspected at the same frequency as the facility's general structural inspection program — typically annually for industrial plants, and additionally after any significant event such as a dropped heavy object, vehicle impact, or nearby fire. The inspection covers three areas:
- Mechanical damage: Impact from dropped tools, fork-truck contact, or vessel mooring on marine structures can cause localized cracking, delamination, or through-thickness fracture of FRP elements. The visual signature is a whitish, opaque area on the surface (stress whitening from resin micro-cracking) or a visible crack line. Any crack that extends through the thickness of a grating panel or structural member should be evaluated for repair or replacement. Surface chips and scratches that do not expose more than a few glass fibers are cosmetic and do not require repair.
- Fastener condition: Check a random sample of grating clips, structural connection bolts, and handrail base plates. Look for loosening (indicated by rust stains if stainless steel fasteners were used — FRP fasteners will not show rust but may show movement marks), and for any signs of local crushing around bolt holes. A torque wrench check on a 10% sample of structural bolts can confirm that the connections remain tight. Re-torque any bolt below 80% of the original specified torque.
- Surface condition: FRP surfaces exposed to UV will, over a period of 10 to 20 years, show a color shift (from gray to a chalky whitish-gray) and may exhibit slight fiber prominence on the surface. This is a cosmetic change in the surface veil and does not affect structural properties. If the surface veil has worn through and glass fibers are visibly exposed and loose, a light application of UV-resistant sealant can restore the surface protection, but this is a long-term cosmetic measure rather than a structural repair.
Cleaning: Pressure Washing with Limits
The most common maintenance action on an FRP structure is cleaning — removing accumulated chemical dust, bird droppings, silt, or process spill residue. Pressure washing with plain water is the standard method. The pressure at the nozzle should not exceed 100 bar (1,450 psi), and the nozzle should be kept at least 300 mm from the surface. Higher pressures, or holding the nozzle close to the surface, can erode the resin-rich surface layer and expose fibers — particularly on molded grating, where the surface resin layer is approximately 0.5 mm thick. Hot water up to 60 °C can be used; above 80 °C, the thermal shock from rapid cooling may induce surface micro-cracks in some resin systems.
For oil or grease contamination, a mild detergent or citrus-based degreaser can be applied with a soft brush before pressure washing. Strong solvents (acetone, MEK, chlorinated solvents) should be avoided — they will attack the resin matrix over time. If a specific chemical cleaner is required due to the nature of the process residue, verify its compatibility with the specific FRP resin system used on the structure before application.
The Absence of a Paint Cycle
FRP structures do not require painting. The color is integral to the resin — typically a gray, green, or orange pigment added during manufacturing. There is no coating to degrade, no surface preparation for recoating, no blasting, no painting crew access requirements. This is not a small advantage: in a chemical plant, a single steel structure repaint can involve scaffolding, containment, grit blasting, and multi-coat application over a 3–4 week period. Removing that line item from the maintenance schedule is often the financial justification for FRP in the first place.
For cleaning and maintenance products compatible with FRP, see our FRP Access Components or contact us regarding specific chemical compatibility.