Installation & Maintenance · 2025-08-25
FRP Grating Lifespan: What 25 Years Actually Looks Like
“25-year design life” is the standard FRP grating claim. What it actually means, environment by environment:
| Environment / resin | Realistic service life | What ages first |
|---|---|---|
| Dry interior, ortho | 30+ yrs | Nothing much — cosmetic UV if sunlit |
| Outdoor splash, ISO | 20–30 yrs | Grit surface micro-wear; UV surface chalk (cosmetic) |
| Wastewater H₂S, ISO | 20–25 yrs | Surface resin in hottest zones |
| Chemical splash, vinyl ester | 20–25 yrs | Only if media/concentration exceeded design |
| Immersion / tidal, vinyl ester | 20+ yrs | Edge zones if panels were site-cut and unsealed |
How FRP ages — honestly
Three mechanisms, none fatal if the panel was specified correctly: UV surface chalking (pigments are stabilized through the section, so it is cosmetic), grit micro-wear under decades of boot traffic (renewable with a PU grit coat), and resin chemical attack only when media exceeded the resistance confirmation. Strength loss from normal aging is gradual and small — the load table you bought is still the load table the deck delivers.
The maintenance list (it is short)
- Annual visual: cracked panels from impacts, missing clips, grit wear in traffic lanes
- Cleaning: hose or pressure-wash; open mesh needs it for drainage, not survival
- Clip check: re-snug any loose hardware on the same visit
- Never: recoat, repaint, galvanize — the absence of these programs is the whole point
The honest comparison: steel's 20-year program is inspection plus recoat cycles plus partial replacement. FRP's is inspection plus a wash. That difference is the entire 20-year cost model.