Step 1: Surface Preparation – The Foundation of a Durable Polyurea Flooring System
Every successful polyurea flooring project begins with proper substrate preparation.
Even the highest-quality polyurea coating cannot compensate for poor concrete conditions.
Common substrate problems include:
Oil contamination
Surface dust
Weak concrete
Cracks
Uneven floors
High moisture content
Old coating residues
The concrete surface should first be mechanically ground using professional diamond grinders.
Grinding removes laitance, weak surface layers, oil contamination, and previous coatings while creating an ideal surface profile for coating adhesion.
Any structural cracks should be cut into V-shaped grooves before being repaired using appropriate repair materials or reinforcement mesh where necessary.
Moisture testing is equally important.
The concrete moisture content should generally remain below 8% before coating installation.
Finally, industrial vacuum cleaners should remove all dust to leave a clean, dry, and roughened substrate.
Without proper surface preparation, later problems such as blistering, peeling, or coating failure become highly likely.
Step 2: Primer Application – Building Strong Adhesion
The primer serves as the bonding bridge between concrete and the polyurea system.
A high-quality penetrating primer seals concrete pores, strengthens weak substrates, and improves adhesion.
Normally, the primer is mixed according to the manufacturer's recommended ratio before being applied by roller or squeegee.
Typical consumption ranges from approximately 0.2–0.3 kg/m², depending on substrate absorption.
The primer should cure completely, usually for 6–12 hours, before proceeding to the next stage.
Applying subsequent coatings before full curing may result in poor interlayer bonding.
Step 3: Intermediate Layer – Creating Strength and Flatness
The intermediate layer acts as the structural backbone of the flooring system.
In industrial facilities with frequent forklift traffic, this layer greatly improves compressive strength and impact resistance.
Polyurea mortar mixed with graded quartz sand is commonly used to level the floor and fill minor surface defects.
The coating is spread evenly using steel trowels at approximately 1–1.5 mm thickness.
After curing, the surface is carefully ground again to eliminate trowel marks and uneven areas.
Any remaining defects are repaired before final cleaning.
This stage determines the flatness of the finished floor and directly influences the appearance of the final coating.
Step 4: Polyurea Spray Coating – The Core Protective Layer
This is the most critical stage of the entire flooring system.
Unlike epoxy, polyurea cannot simply be rolled or brushed.
Professional high-pressure heated spray equipment is required.
Component A and Component B are heated separately before entering the spray gun, where they mix instantly under high pressure.
The chemical reaction begins immediately, with gel time often occurring within **10 seconds**.
The coating is typically applied at 1.5–2.5 mm thickness in one continuous spray application.
Critical locations such as floor joints, corners, drains, and wall intersections usually receive additional coating thickness for enhanced waterproof performance.
During spraying, environmental conditions must be carefully controlled.
Relative humidity should remain below 80%, and substrate temperature should stay at least 3°C above the dew point to prevent condensation.
Workers should wear supplied-air respirators and appropriate protective equipment throughout installation.
Step 5: Topcoat Application – Improving UV Resistance and Appearance
Although aromatic polyurea provides excellent mechanical protection, prolonged ultraviolet exposure may gradually cause discoloration.
For outdoor applications, an aliphatic polyurea topcoat is strongly recommended.
The topcoat significantly improves:
UV resistance
Weather resistance
Color stability
Surface cleanliness
Chemical stain resistance
After the polyurea layer fully cures, the surface is lightly sanded and cleaned before applying the topcoat by roller or spray.
Normally two thin coats produce better results than one thick application.
For indoor industrial floors, the topcoat may be optional depending on project requirements.
However, for outdoor facilities exposed to continuous sunlight, it is considered essential.
Step 6: Curing and Final Protection
Even though polyurea cures extremely quickly, complete system performance still requires proper post-installation protection.
General recommendations include:
No pedestrian traffic within the first 24 hours.
Prevent water exposure or chemical spills during initial curing.
Light mechanical traffic after approximately 72 hours.
Full industrial operation after about seven days.
Construction areas should remain isolated to prevent contamination from other trades.
Before project handover, many contractors perform water testing to verify waterproof performance around drains, corners, and other critical areas.