In-Place Pile Repair for Demanding Marine Environments

29 January 2026

(Image credit: Denso)

Denso, Inc., a global leader in corrosion prevention and sealing technologies, has highlighted the SeaShield Series FX-70^® pile repair and protection system, a cost-effective, long-term solution engineered to restore and protect damaged steel, concrete, and timber piles in harsh marine and waterfront environments. Originally introduced in 1970 as the industry’s first in-place structural pile repair solution, the FX-70 system has more than five decades of proven field performance, with many early installations still in service today. The system combines custom-made fiberglass jackets with high-strength, water-insensitive repair materials to deliver durable in-place repairs, often without taking structures out of service.

At the core of the SeaShield Series FX-70 system is a custom-made, tongue-and-groove-seamed fiberglass jacket that forms a tight, continuous shell around each pile. The fiberglass jacket serves as a stay-in-place form and provides a corrosion-resistant protective shell for the life of the repair, shielding piles from seawater, chemicals, weathering, and erosion. High-strength, water-insensitive epoxy and cementitious repair grouts and mortars are placed inside the jacket, where they bond to concrete, timber, and steel piles to strengthen, repair, and protect damaged sections in wet, tidal, and fully submerged conditions. Depending on the extent of section loss, the FX-70 system can be configured using epoxy grout alone or in combination with non-shrink, anti-washout cementitious underwater grout, with repair details determined by the engineer.

During installation, the repair materials displace existing water and can be pumped, tremied, or poured into the SeaShield FX-70 jacket even while the pile is submerged. This true in-water placement capability eliminates the need for expensive cofferdams or dewatering. By allowing repairs to be completed in place, the system helps reduce overall project cost and loss-of-use, as structures can generally remain in service during installation.

Engineered for versatility, the SeaShield Series FX-70 system accommodates piles of various shapes and sizes, including round, square, and H-piles, in both underwater and dry environments. The system’s modular fiberglass jackets are custom-fabricated for each project and installed using mechanical fasteners and epoxy-bonded tongue-and-groove joints, eliminating the need for heavy-lifting equipment. This flexibility allows engineers and contractors to standardize on a single repair system across diverse pile geometries and site conditions, simplifying design and inventory.

Once installed, the SeaShield Series FX-70 system forms a low-maintenance protective envelope around the repaired pile, preventing corrosion, deterioration, weathering, and erosion. With decades of documented performance in marine structures worldwide, the FX-70 system provides owners with a durable, long-term repair and protection solution.

The materials used in the SeaShield Series FX-70 system are safe for use in marine-life habitats, supporting repairs in environmentally sensitive areas.

In addition to performance benefits, the system is designed to blend easily with existing structures, helping owners maintain the visual appearance of piers, bridges, and waterfront assets while upgrading underlying structural protection. As a structural pile repair and protection system for steel, concrete, and timber piles, SeaShield Series FX-70 offers a single, integrated solution for extending the service life of critical marine and waterfront infrastructure.