Read Before You Estimate, Mobilize, or Apply

A protective-lining specification is more than a product name and a required film thickness. It defines the work the contractor is expected to perform and the conditions under which the completed lining will be accepted.

Important requirements may be spread across drawings, general conditions, coating schedules, referenced standards, product data sheets, addenda, inspection plans, safety requirements, and owner procedures. Reading only the paragraph that names the lining material can leave major obligations undiscovered.

The specification should be reviewed during estimating, again before purchasing materials, and once more with supervisors, applicators, and inspectors before work begins.

Identify the Complete Contract Document Package

Before reviewing individual requirements, determine which documents apply and which document controls if two requirements conflict. The contract may establish an order of precedence among documents.

The applicable package may include:

• The project specification
• Drawings and coating schedules
• Bid documents and scope clarifications
• Addenda and approved substitutions
• Manufacturer product data sheets
• Manufacturer application instructions
• Safety Data Sheets
• Referenced AMPP, ASTM, OSHA, and other standards
• Owner inspection and quality requirements
• Approved written responses to requests for information

1. Confirm the Scope of Work

Start by identifying exactly which surfaces are included. A tank-lining project may include the shell, floor, roof underside, columns, supports, rafters, ladders, nozzles, manways, sumps, piping, bolts, welds, and other internal components.

Determine whether the contractor is responsible for:

• Removing the existing lining
• Cleaning and decontaminating the structure
• Repairing steel, concrete, welds, cracks, or bugholes
• Providing ventilation, heating, cooling, or dehumidification
• Providing access, scaffolding, lighting, and containment
• Protecting adjacent equipment and completed work
• Testing, inspection assistance, and documentation
• Waste collection, characterization, and disposal

2. Verify the Service Environment

The specification should identify what the lining will contain and the expected operating conditions. Compare this information with the lining manufacturer's written chemical-resistance and temperature limitations.

Look for the exact chemical or product, concentration, normal temperature, maximum temperature, immersion cycle, cleaning process, abrasion, pressure, and expected return-to-service conditions. If this information is missing or differs from actual plant operation, request written clarification.

3. Identify the Complete Lining System

Do not treat the named finish material as the entire system. The specification may require a primer, resurfacer, stripe coat, lining coats, reinforcement, aggregate, repair compound, and finish coat.

4. Read Every Surface-Preparation Requirement

Surface preparation requirements should identify more than a general cleaning method. For steel, review the required degree of cleanliness, surface profile, soluble-salt limits, dust removal, edge preparation, weld treatment, flash-rust restrictions, and time allowed before coating.

For concrete, review curing requirements, laitance removal, surface strength, moisture testing, surface texture, contamination, crack repair, bughole filling, and treatment of joints and penetrations.

Confirm how cleanliness, profile, dust, salts, moisture, and other conditions will be measured. The method, frequency, acceptance criteria, and responsible party should be understood before preparation begins.

5. Find the Environmental Limits

The specification and product data normally establish acceptable air temperature, surface temperature, relative humidity, and separation from the dew point. They may also address condensation, ventilation, air movement, heating, cooling, lighting, and dehumidification.

Determine how often environmental conditions must be measured and recorded. Conditions inside a tank can differ from readings outside the structure. Readings should represent the actual work area and substrate.

6. Review Mixing and Application Instructions

Confirm requirements for:

• Material storage and conditioning temperature
• Mixing ratio and whether partial units are permitted
• Mixing equipment and mixing time
• Induction or sweat-in time
• Pot life at the expected temperature
• Permitted thinner and maximum thinning
• Application equipment and spray-tip range
• Wet-film and dry-film thickness per coat
• Minimum and maximum recoat times
• Required cure before inspection and service

When the specification and current manufacturer instructions differ, do not choose whichever requirement is easier. Submit the conflict for written resolution.

7. Understand Film-Thickness Requirements

Determine whether the specified thickness applies to each coat, the complete system, or both. Review the permitted minimum, maximum, and range as well as the number and location of readings.

More material is not automatically better. Excessive thickness can produce solvent entrapment, sagging, cracking, poor cure, or internal stress. Insufficient thickness can leave weak areas or reduce barrier performance.

8. Locate Every Inspection Hold Point

A hold point is a stage of work that must be inspected or accepted before the contractor proceeds. Covering work before a required inspection can result in rejection even if the completed lining appears acceptable.

Common hold points include:

• Initial substrate condition
• Repairs to steel, concrete, welds, cracks, and details
• Completed surface preparation
• Surface profile, dust, salt, or moisture testing
• Primer and stripe-coat application
• Individual lining coats
• Dry-film thickness
• Holiday or discontinuity testing
• Completed repairs
• Final cure and acceptance

9. Identify Required Testing

The specification should identify the test method, equipment, frequency, acceptance criteria, responsible party, reporting requirement, and repair procedure for an unacceptable result.

Testing may include:

• Visual inspection
• Surface profile measurement
• Soluble-salt testing
• Concrete moisture testing
• Wet-film and dry-film thickness measurement
• Holiday or discontinuity detection
• Adhesion testing
• Hardness or cure verification
• Final cleanliness or service-readiness inspection

10. Understand Repair and Retesting Requirements

The specification should explain how defects are marked, prepared, repaired, cured, and retested. Confirm the required overlap onto sound lining, permitted repair material, surface-preparation method, recoat requirements, and retesting procedure.

Repair work should be documented with the same care as the original application. A repair is not complete merely because the defect has been covered.

11. List Every Required Record and Submittal

Documentation requirements affect staffing, instruments, scheduling, and cost. They should be included in the estimate and quality-control plan.

• Product data and Safety Data Sheets
• Batch numbers and expiration dates
• Material-storage temperature records
• Environmental-condition logs
• Surface-preparation and cleanliness records
• Mixing and application records
• Wet-film and dry-film thickness reports
• Holiday-test and repair reports
• Instrument calibration or verification records
• Final inspection and acceptance documentation

When to Submit a Request for Information

A request for information should be submitted when the documents are incomplete, inconsistent, or unsuitable for the observed conditions. Examples include:

• The specified product differs from the approved submittal
• The actual service differs from the stated service
• The specified thickness conflicts with manufacturer instructions
• The substrate contains defects not addressed by the specification
• The required surface preparation cannot be achieved
• The recoat or cure schedule conflicts with the project schedule
• The inspection method or acceptance criteria are unclear

Specifications Do Not Replace a Safety Plan

A technical lining specification may identify hazards or safety requirements, but it does not replace the contractor's responsibility to evaluate the work and comply with applicable safety regulations.

Review Safety Data Sheets, confined-space requirements, respiratory protection, ventilation, fire and explosion hazards, high-pressure equipment, electrical classification, access, rescue, and waste-handling requirements before work begins.

The Key Takeaway

A good specification review converts a stack of contract documents into a practical work plan. The contractor should know what must be prepared, applied, measured, witnessed, repaired, documented, and accepted before mobilization.

Read the specification before pricing the work. Resolve questions before applying material. Document the work before the evidence is covered.

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