Corrosion is a perpetual challenge for companies and government authorities managing infrastructure, facilities, or utilities. Whether it’s pipelines, bridges, or power plants, effective rehabilitation is essential to ensure safety, performance, and longevity. This article outlines a five-step structured approach to properly repairing corroded assets, including key steps to assess, plan, and execute rehabilitation projects.

1. Documentation review

The first step in rehabilitation projects is to review all the documentation available for the asset. This includes:

• Drawings, technical specifications, and reports: review initial project drawings, technical details, and construction reports, including expansions or previous repairs, to identify design changes and challenges.  
• Original coating system: identify the materials, means, and methods used in the original corrosion protection systems.
• Past repairs: review historical repair records to understand previous issues, techniques, and their effectiveness.
• Hazardous substances: Check for the presence of hazardous materials such as lead-based coatings or asbestos, which could complicate repairs and require specialized safety procedures and environmental protection measures.

Proper documentation ensures the repair project starts with accurate baseline information and identifies potential safety or material compatibility challenges.

2. Failure mode analysis

Understanding why corrosion occurs is crucial to preventing recurrence. A failure mode analysis typically includes:

• Type of corrosion: observe whether the corrosion is uniform or localized, and determine its cause such as environmental factors, workmanship, or design.
• Root causes: evaluate environmental conditions, construction issues, or operational stresses that may contribute to the corrosion.
• Corrosion survey: map out areas of structural weakness and rank the extent of the damage following industry standards and non-destructive testing (NDT) techniques.

By identifying the root cause, targeted solutions can be implemented to ensure long-term effectiveness.

3. Coating compatibility assessments

Selecting a new or compatible coating system is essential to protect assets after repair. Key considerations include:

• Existing coatings: determine compatibility between existing and new coating systems to prevent adhesion failures or chemical reactions.
• Environmental factors: consider how exposure to environmental factors and chemicals impacts the repair coating application and durability.
• Industry standards: refer to standards such as ISO, NACE, or SSPC to ensure the chosen coating system meets durability and performance requirements for a given service.

Compatibility assessments help ensure rehabilitation plans will deliver the expected service life.

4. Repair plan

Developing a detailed repair plan sets the foundation for successful rehabilitation. The plan should include:

• Scope of work: define the specific areas of repair and the methods to be used.
• Accessibility and environmental protection: assess the options and outline protocols for hazardous material handling, worker safety, and environmental compliance.  
• Materials and equipment: determine the materials, tools, and equipment needed to execute the rehabilitation project cost-effectively.
• Procedures and standards: define industry procedures and standards for each repair process aligned with the asset’s service life extension expectations.
• Timeline and resources: estimate project timelines, budget, and workforce requirements.

A comprehensive plan ensures that all stakeholders understand the repair process challenges and objectives.

5. Rehabilitation execution

The execution phase involves implementing the repair plan with precision. Key steps include:

• Structural repairs: conduct necessary welding and bolting, to restore asset integrity.
• Surface preparation: use substrate cleaning methods such as abrasive blasting or power tool cleaning to remove dirt, rust, contaminants, and deteriorated coatings.
• Coating application: apply the selected protective coating system following manufacturer guidelines and industry standards.
• Quality control: inspections and tests must be performed at key repair steps to ensure work meets defined specifications.