You are here: Knowledge Base > 10. Academy Series

Commercial and Industrial Floor Coatings | Article 23 of 24 | Inspection, Testing, Defects and Repairs
Last Updated: 09/21/2026

Commercial and Industrial Floor Coatings Certificate Program emblem

Commercial and Industrial Floor Coatings for Professional Contractors

Article 23 of 24

Floor-Coating Inspection, Testing, Defects, and Repairs

Finding Problems Early and Correcting Their Causes

Quality control does not begin after the final coat is installed. Professional floor-coating inspection starts with the concrete and continues through preparation, mixing, application, cure, final testing, repair, and acceptance.

Inspection Is a Process, Not a Final Walkthrough

A final inspection can identify visible defects, but it cannot reconstruct conditions that were never measured or work that was covered by later coats. Once a flooring system is complete, the concrete profile, repair preparation, primer coverage, embedded aggregate, and individual layer thicknesses may no longer be visible.

Each stage should therefore be inspected and accepted before it is covered. The contractor should record materials, batch numbers, mixing times, environmental conditions, application quantities, coverage, cure intervals, testing, and repairs.

Good documentation protects the owner and the contractor. It shows what was done, where it was done, which conditions existed, and how the completed work was evaluated.

Four Stages of Floor-Coating Inspection

1. Pre-Installation

Confirm the concrete condition, moisture results, contamination, repairs, joints, access, environmental controls, materials, equipment, and approved system.

2. Surface Preparation

Verify cleanliness, soundness, surface profile, dust removal, repair acceptance, edge preparation, and detail readiness.

3. Application

Observe mixing, batch control, coverage, film thickness, aggregate distribution, recoat timing, workmanship, and environmental conditions.

4. Final Acceptance

Inspect appearance, cure, texture, continuity, adhesion, thickness, details, repairs, cleanliness, and readiness for the intended service.

Pre-Installation Inspection

The contractor should inspect the work area before mobilizing application crews. Existing conditions should be documented with written notes, marked drawings, test reports, and dated photographs.

Concrete age, condition, strength, and previous repairs
Cracks, joints, spalls, delamination, and surface laitance
Oil, grease, chemicals, curing compounds, sealers, and adhesives
Moisture test locations, methods, conditions, and results
Floor flatness, slope, drainage, and standing-water areas
Drains, penetrations, equipment bases, walls, and transitions
Ambient and concrete temperature, humidity, and dew point
Required mockups, test areas, colors, textures, and acceptance criteria

Conditions outside the contract requirements should be reported in writing before work proceeds. Beginning installation without documenting an unacceptable substrate may transfer unnecessary risk to the flooring contractor.

Inspecting Surface Preparation

Prepared concrete should be clean, sound, dry as required, and uniformly profiled for the selected system. The correct profile exposes sound concrete without unnecessarily damaging the slab.

Preparation Acceptance Questions

Has weak laitance and unsound concrete been removed?
Does the surface match the specified concrete surface profile?
Have oil, grease, chemicals, adhesives, and other contaminants been removed?
Are edges, corners, drains, and vertical surfaces properly prepared?
Has dust been removed using suitable industrial vacuum equipment?
Are cracks, joints, and repairs ready to receive the flooring system?
Has the concrete been damaged by overly aggressive preparation?
Have all required tests and inspections been documented?

Preparation acceptance should occur before primer application. Photographs and written records should include representative floor areas as well as cracks, drains, edges, repairs, and transitions.

Application Quality-Control Checks

Inspection Point	What to Verify	Why It Matters
Material identity	Correct product, component, color, batch, and expiration status	Prevents incompatible or incorrect materials from entering the system
Mix ratio	Complete units or accurately proportioned components	Incorrect ratios can prevent proper cure and property development
Mixing	Correct equipment, speed, time, sequence, and container scraping	Reduces unmixed material, air entrainment, and inconsistent cure
Environmental conditions	Air temperature, surface temperature, humidity, and dew point	Conditions affect condensation, flow, working time, and cure
Coverage and thickness	Area covered, material consumed, wet film, and system build	Under-application may reduce performance and hide defects poorly
Aggregate	Correct type, cleanliness, broadcast rate, and distribution	Aggregate affects thickness, texture, wear, and slip resistance
Recoat interval	Minimum and maximum times for each floor section	Incorrect timing can cause trapped material or poor intercoat adhesion
Workmanship	Uniformity, edges, seams, roller marks, bubbles, debris, and missed areas	Early correction is easier before the coating cures or is covered

Common Floor-Coating Defects

A defect is a visible or measurable condition that differs from the approved requirement. The appearance of a defect may suggest a cause, but diagnosis should be based on evidence rather than appearance alone.

Pinholes and Bubbles

Possible causes include concrete outgassing, air introduced during mixing, porous concrete, incorrect rolling, excessive film thickness, or unsuitable environmental conditions.

Blisters

Possible causes include moisture vapor, osmotic pressure, contamination, trapped solvent or water, poor adhesion, and application over an unacceptable substrate.

Delamination

Possible causes include weak concrete, laitance, contamination, insufficient profile, condensation, missed recoat windows, and incompatible materials.

Soft or Uncured Areas

Possible causes include incorrect proportioning, incomplete mixing, wrong components, low temperature, contamination, or application beyond usable working time.

Fish Eyes and Craters

Possible causes include silicone, oil, grease, cleaning residue, airborne contamination, or poor surface wetting.

Uneven Color or Gloss

Possible causes include batch variation, incomplete mixing, unequal thickness, inconsistent rolling, different cure conditions, or contamination.

Peeling at Edges

Possible causes include weak terminations, insufficient edge preparation, impact, water intrusion, feathered coating edges, or movement at transitions.

Cracking

Possible causes include concrete movement, reflective cracking, shrinkage, structural movement, thermal stress, incorrect joint treatment, or an overly rigid repair.

Diagnose the Cause Before Repairing the Symptom

A blister can be cut out and filled, but the repair may fail again if moisture vapor, contamination, or poor preparation remains beneath it. A crack can be coated over, but it may reflect through again if the crack is moving.

Defect investigation should determine:

Where the defect occurs and whether it follows a pattern
Which flooring layer failed
Whether the failure is adhesive, cohesive, or within the concrete
Whether moisture, contamination, movement, or chemical exposure is present
Whether mixing, coverage, temperature, or recoat records reveal a connection
Whether the condition is isolated or representative of a larger problem

The visible edge of a defect may not show its full extent. Sounding, probing, adhesion testing, moisture evaluation, sample removal, or other investigation may be needed to establish repair boundaries.

Useful Inspection and Testing Methods

Method	Purpose	Important Limitation
Visual inspection	Identifies appearance, contamination, missed areas, texture, and visible defects	Cannot confirm hidden bond strength, moisture, or complete cure
Concrete surface-profile comparison	Compares prepared concrete with recognized profile references	Requires representative inspection across the complete floor
Wet-film measurement	Checks applied thickness while material is wet	May be difficult on textured or aggregate-filled systems
Material usage calculation	Compares installed area with the quantity of material consumed	Does not show local thin or thick areas
Pull-off adhesion testing	Measures tensile adhesion strength and identifies the failure plane	Is destructive and requires proper test locations and repairs
Holiday or continuity testing	Locates discontinuities in suitable nonconductive lining systems	Voltage and procedure must match the system thickness and specification
Hardness or cure evaluation	Assesses whether material has developed expected cure properties	Results must be interpreted using the product and approved procedure
Moisture testing	Evaluates moisture conditions in or at the concrete slab	Different tests measure different conditions and are not interchangeable

Testing Floor-Coating Thickness

Measuring thickness on concrete is more difficult than measuring a coating on smooth metal. Concrete is rough and variable, and many flooring systems contain aggregate or multiple layers.

Contractors commonly control thickness through a combination of:

Measured floor area
Known material volume
Specified coverage rate
Wet-film measurements where practical
Placement gauges or depth checks for thicker systems
Core or sample measurements when specified
Recorded aggregate and resin consumption

Material usage alone is not enough. Extra material around drains, cracks, coves, low areas, and waste can make the average usage appear correct while portions of the floor remain thin.

Adhesion Testing

Pull-off testing can help evaluate the tensile bond between the flooring system and concrete. A loading fixture is bonded to the surface, the coating is cut around the fixture when required, and tensile force is applied perpendicular to the floor.

The reported strength is important, but the failure location is also critical. Failure may occur:

Within the concrete
At the concrete-to-primer interface
Within one of the flooring layers
Between flooring layers
Within the adhesive used to attach the testing fixture

Test frequency, locations, acceptance values, concrete condition, equipment, adhesive cure, cutting procedure, and repair method should be agreed upon before testing begins.

Holiday and Continuity Testing

Holiday testing is used on certain nonconductive coating and lining systems to locate pinholes, voids, or discontinuities. It is most commonly associated with systems intended to provide continuous protection against liquid or chemical exposure.

The test method and voltage must be appropriate for the coating type, thickness, substrate, and specification. Excessive voltage or an unsuitable method can damage the system. Testing should be performed only after the coating has cured sufficiently.

Important: Do not perform holiday testing simply because a tester is available. Obtain the flooring manufacturer's written approval and follow the specified test method, voltage, cure time, and repair procedure.

Developing a Repair Procedure

Repairs should restore the required bond, thickness, continuity, texture, chemical resistance, appearance, and cleanability. The written procedure should identify:

The confirmed or suspected cause of the defect
The boundaries of unsound or unacceptable material
The method for removing defective material
The required edge geometry and surface preparation
The repair materials and installation sequence
Environmental and substrate conditions
Recoat and cure requirements
Final inspection and testing

Repair edges should not be left as thin, weak feathers unless the repair system specifically permits that detail. Saw-cut, keyed, or otherwise defined terminations may be required to provide a durable transition.

Repair Appearance and Owner Expectations

A structurally sound repair may remain visible. Differences in age, batch, texture, aggregate distribution, color, gloss, lighting, and application method can make an isolated repair noticeable.

Before repairing a prominent area, the contractor and owner should agree whether the objective is:

Functional restoration only
A localized color- and texture-matched repair
Recoating to natural boundaries
Recoating the entire room or floor area

Expectations should be documented before work begins. Terms such as invisible repair or perfect match should be avoided unless a representative mockup proves that result is achievable.

Practical Contractor Checklist

Establish inspection and acceptance criteria before mobilization.
Document existing concrete conditions and previous repairs.
Record moisture testing, environmental conditions, and surface profile.
Inspect each stage before it is covered by the next layer.
Track products, batch numbers, mix times, quantities, and coverage.
Record recoat times for each floor section.
Correct bubbles, pinholes, debris, and missed areas while access remains practical.
Identify the failure plane and underlying cause before developing a repair.
Obtain manufacturer guidance for uncertain defects or major repairs.
Define repair boundaries, materials, preparation, and acceptance tests.
Discuss the expected appearance of repaired areas with the owner.
Complete and document final inspection before releasing the floor.

Safety and Professional Responsibility

Inspection and repair work can involve cutting, grinding, drilling, solvents, reactive resins, electrical test equipment, and exposure to operating facilities. Follow current safety data sheets, equipment instructions, respiratory-protection requirements, dust-control procedures, lockout/tagout rules, and site-specific safety plans.

Testing should be performed by qualified personnel using suitable, calibrated, and verified equipment. The contractor should not alter test locations, acceptance values, or procedures merely to obtain a passing result.

Key Takeaway

The best inspection program finds problems while they can still be corrected. Inspect every stage, record the conditions, use appropriate tests, diagnose causes rather than symptoms, and repair the floor using a written procedure with defined acceptance requirements.

Knowledge Check

1. Why is final inspection alone insufficient?

Later layers hide the concrete profile, repairs, primer, embedded aggregate, and earlier coats. Each stage must be inspected before it is covered.

2. Why should the failure plane be recorded during adhesion testing?

The failure location helps determine whether the weakness is within the concrete, at the concrete-to-coating interface, within a flooring layer, or between layers.

3. Why is material usage not enough to confirm uniform floor thickness?

Waste and extra material used at cracks, drains, coves, and low areas may make average consumption appear correct while other portions remain below the required thickness.

4. What should be determined before repairing a blister or delaminated area?

The underlying cause and the complete extent of unsound material should be determined. Repairing only the visible symptom may allow the failure to return.

5. Why should repair appearance be discussed with the owner in advance?

A functional repair may remain visible because of differences in color, gloss, texture, aggregate, application, or material age. The expected appearance and repair boundaries should be agreed upon before work begins.

Technical References

ASTM D4258, Standard Practice for Surface Cleaning Concrete for Coating.
ASTM D4259, Standard Practice for Abrading Concrete.
ASTM D4263, Standard Test Method for Indicating Moisture in Concrete by the Plastic Sheet Method.
ASTM F2170, Standard Test Method for Determining Relative Humidity in Concrete Floor Slabs Using In Situ Probes.
ASTM D4414, Standard Practice for Measurement of Wet Film Thickness by Notch Gages.
ASTM D7234, Standard Test Method for Pull-Off Adhesion Strength of Coatings on Concrete Using Portable Pull-Off Adhesion Testers.
ASTM D4787, Standard Practice for Continuity Verification of Liquid or Sheet Linings Applied to Concrete Substrates.
ICRI Technical Guideline No. 310.2R, Selecting and Specifying Concrete Surface Preparation for Sealers, Coatings, Polymer Overlays, and Concrete Repair.
ICRI Concrete Surface Profile comparator chips and related surface-preparation guidance.
Current technical data sheets, safety data sheets, application instructions, repair procedures, and written recommendations supplied by the flooring-system manufacturer.

Standards and manufacturer documents may be revised. Confirm that the current edition and the correct project-specified requirements are being used.

Return to the Course Overview

No part of this material may be reproduced, distributed, transmitted, stored, or used in any form without prior written permission from Azimuth Spray Systems, LLC, except for brief quotations used with proper attribution.

AirSprayTech.com - The Finishing Authority®

Tags: floor coating inspection, coating defects, concrete coating testing, floor coating repairs, adhesion testing, dry film thickness, holiday testing, resinous flooring defects

Related Articles