1. Introduction: When Ordinary Coatings Fail
In regions with extreme weather, ordinary waterproof coatings fail. They crack in freezing temperatures, chalk under intense UV, and delaminate during thermal cycling.
ProFlex 680E is a premium industrial roof coating and waterproofing solution engineered for the world’s harshest environments.
Siberian winters (-30°C)
Desert summers (+50°C with intense UV)
Coastal humidity and salt spray
Chemical plant exposure
This one-component, moisture-curing polyurethane delivers uncompromising protection where other coatings give up.
2. What is ProFlex 680E?
ProFlex 680E is a single-component, solvent-based polyurethane coating that cures by reacting with moisture in the air.
Key Characteristics:
| Property | Description |
|---|---|
| Chemistry | One-component aromatic polyurethane |
| Curing Mechanism | Moisture cure (reacts with humidity) |
| Solvent Content | Moderate VOC (for maximum penetration) |
| Film Build | Thin to medium build (200-500 microns) |
| Service Temperature | -30°C to +90°C |
| UV Stability | Good (with topcoat) / Excellent (self-standing) |
Common Names for This Product:
Solvent-based polyurethane coating
One-component PU waterproofing
Moisture-cure polyurethane
Industrial roof coating
Concrete protective coating
3. ProFlex 680E vs. Waterborne Polyurethane: What's the Difference?
Many customers ask: “Why choose solvent-based over waterborne?” Here’s the honest comparison:
| Feature | ProFlex 680E (Solvent-Based) | Waterborne Polyurethane (e.g., AQUAFLEX 590) |
|---|---|---|
| Penetration into Concrete | Excellent (solvent carries resin deep) | Surface-level only |
| Adhesion to Problematic Substrates | Excellent (oily, damp, difficult surfaces) | Requires perfect preparation |
| Low-Temperature Cure | Cures down to -5°C | Requires +5°C minimum |
| Chemical Resistance | Excellent | Good |
| UV Resistance | Good (with aliphatic topcoat) | Excellent (aliphatic) |
| VOC Content | Moderate | Low / Zero |
| Odor During Application | Strong solvent odor | Low odor |
| Application Window | Can stop and restart (no pot life) | No pot life |
When to Choose ProFlex 680E:
| Scenario | Recommendation |
|---|---|
| Freeze-thaw climates | ProFlex 680E (flexible at -30°C) |
| Damp substrates | ProFlex 680E (moisture-cure tolerates dampness) |
| Concrete with poor surface | ProFlex 680E (penetrates deep) |
| Indoor applications / occupied spaces | Choose waterborne (AQUAFLEX 590) |
| Green building / LEED projects | Choose waterborne |
4. Technical Specifications
Here are the verified specifications for ProFlex 680E, essential for engineers and specifiers:
| Parameter | Value | Test Method |
|---|---|---|
| Solid Content | 65% ± 2% | ASTM D1644 |
| Viscosity | 2000-3000 cPs | ASTM D2196 |
| Tensile Strength | ≥ 6 MPa | ASTM D412 |
| Elongation at Break | ≥ 500% | ASTM D412 |
| Tear Resistance | ≥ 15 N/mm | ASTM D624 |
| Adhesion to Concrete | ≥ 2.0 MPa (concrete failure) | ASTM D4541 |
| Adhesion to Steel | ≥ 4 MPa | ASTM D4541 |
| Hardness (Shore A) | 80-85 | ASTM D2240 |
| Low-Temperature Flexibility | Pass at -30°C (no cracking) | ASTM D522 |
| Water Vapor Permeability | Low | ASTM E96 |
| UV Resistance (with topcoat) | Excellent (10+ years) | ASTM G154 |
| Application Temperature | -5°C to +40°C | – |
| Coverage Rate | 0.8 – 1.2 kg/m² per coat | – |
| Tack-Free Time | 2-4 hours (at 25°C, 60% RH) | – |
| Full Cure | 7 days | – |
Low-Temperature Performance:
| Temperature | Curing Behavior | Flexibility |
|---|---|---|
| +25°C | Normal cure (tack-free 2-3 hrs) | 500% elongation |
| +5°C | Slow cure (tack-free 6-8 hrs) | 500% elongation (after cure) |
| -5°C | Very slow cure (24+ hrs tack-free) | 450% elongation (after full cure) |
| -30°C (service) | N/A (already cured) | No cracking on bend test |
5. Primary Applications: Where ProFlex 680E Excels
Why ProFlex 680E is the Ideal Industrial Roof Coating
Industrial roofs face unique challenges: chemical exposure, foot traffic, extreme temperatures, and long-term UV. ProFlex 680E is specifically formulated as a heavy-duty industrial roof coating that:
Applies in cold weather (down to -5°C)
Remains flexible at -30°C (no winter cracking)
Resists industrial chemicals and fallout
Withstands maintenance foot traffic
Provides 10+ years of service life with proper topcoat
5.1 Industrial Roofs in Extreme Climates
Flat and low-slope roofs on industrial buildings face the harshest conditions: thermal cycling, ponding water, UV, and foot traffic.
Why ProFlex 680E:
Flexibility at -30°C: Won’t crack during winter
UV Resistance: With years of sun exposure (with proper topcoat)
Chemical Resistance: Protects against industrial fallout
Foot Traffic Tolerant: Maintenance workers can walk on it
Ideal Substrates:
Concrete roof decks
Metal roofs (corrugated steel)
Spray polyurethane foam (SPF) roofs
Modified bitumen overlays
5.2 Bridges and Infrastructure
Concrete bridges in cold climates suffer from de-icing salts, freeze-thaw cycles, and carbonation.
ProFlex 680E provides:
Chloride ion resistance: Protects rebar from corrosion
Crack bridging: 500% elongation accommodates movement
Low-temperature application: Can be applied in colder months
5.3 Concrete Protection in Coastal Areas
Marine environments combine salt spray, humidity, and UV.
Why ProFlex 680E:
Excellent adhesion to damp concrete
Resists salt water intrusion
Flexible enough to handle concrete movement
5.4 Secondary Containment
Chemical storage areas need coatings that resist spills and aggressive chemicals.
ProFlex 680E offers:
Resistance to acids, alkalis, and solvents
Seamless, monolithic membrane
Easy to inspect and repair
5.5 Water and Wastewater Treatment Plants
Treatment facilities expose concrete to chemicals, abrasion, and constant moisture.
ProFlex 680E:
Withstands chlorine and other treatment chemicals
Protects against hydrogen sulfide corrosion
Can be applied to damp surfaces
6. Application Guide: How to Apply ProFlex 680E in Cold Weather
One of ProFlex 680E’s biggest advantages is its ability to cure at low temperatures. Here’s how to get the best results:
Step 1: Surface Preparation (Critical)
Concrete:
Surface must be clean, sound, and free of contaminants
Mechanical preparation: Shot blasting or grinding recommended
Moisture tolerance: Up to 8% moisture content (unlike epoxies that require bone-dry)
Metal:
Abrasive blasting to Sa 2.5 (Near White Metal)
Apply metal primer if specified
Step 2: Priming
| Substrate | Primer Recommendation |
|---|---|
| Concrete (sound) | No primer needed (first coat acts as primer) |
| Concrete (porous) | Dilute ProFlex 680E 10-20% with xylene |
| Steel | Epoxy primer recommended |
| Old coatings | Test adhesion first |
Step 3: Mixing (Simple)
Unlike two-component systems, ProFlex 680E is ready to use:
Stir thoroughly before use (pigments may settle)
Do not thin unless specified
No pot life—use what you need, save the rest
Step 4: Application
Tools:
Roller: Short-nap roller for smooth surfaces
Brush: For details, corners, penetrations
Airless spray: For large areas (tip size 0.019″-0.023″)
Number of Coats:
Typically 2 coats
First coat: Apply evenly, ensure penetration
Second coat: Apply after first is tack-free (4-24 hours)
Wet Film Thickness:
Target 200-300 microns per coat
Total thickness: 400-600 microns
Step 5: Curing in Cold Weather
| Temperature | Recoat Window | Foot Traffic | Full Cure |
|---|---|---|---|
| 25°C | 4-8 hours | 24 hours | 7 days |
| 10°C | 12-24 hours | 48 hours | 10 days |
| 0°C | 24-48 hours | 72 hours | 14 days |
| -5°C | 48-72 hours | 5-7 days | 21 days |
Important: Do not apply if rain or freezing is expected within 4 hours of application.
6.1 Cold Weather Application Tips
| Challenge | Solution |
|---|---|
| Slow curing | Plan longer intervals between coats |
| Higher viscosity | Store material at room temperature before use |
| Condensation on surface | Warm surface slightly or wait for drier conditions |
| Ice / frost | Do not apply—surface must be dry |
7. Safety and Handling
Solvent-based polyurethane contains flammable solvents. Follow these precautions:
| Hazard | Precaution |
|---|---|
| Flammability | Keep away from sparks, open flames—no smoking |
| Inhalation | Wear NIOSH-approved respirator with organic vapor cartridges |
| Skin Contact | Wear nitrile gloves, chemical-resistant clothing |
| Eye Contact | Wear safety goggles |
| Ventilation | Ensure adequate ventilation—explosion-proof equipment required |
| Storage | Store in cool, dry place away from ignition sources |
8. Color Options and Topcoats
ProFlex 680E is available in:
| Option | Description |
|---|---|
| Standard Colors | Gray, Light Gray, Tan |
| Custom Colors | Available on request (MOQ applies) |
| With Aluminum | Reflective version for roofs (heat reduction) |
UV Protection Strategy:
ProFlex 680E is an aromatic polyurethane—it will yellow and chalk over time with UV exposure. For maximum longevity:
| Option | Best For | UV Life |
|---|---|---|
| ProFlex 680E alone | Industrial roofs (appearance not critical) | 3-5 years before chalking |
| With aliphatic topcoat | Architectural / visible areas | 10+ years color retention |
| With reflective coating | Energy-efficient roofs | 5-8 years |
Recommendation: For exposed applications where appearance matters, apply a ProFlex 680E base coat + aliphatic polyurethane topcoat (ask about our ProFlex 690 series).
9. Frequently Asked Questions (FAQ)
Q1: What’s the difference between ProFlex 680E and ProFlex 2K?
| Product | Type | Best For |
|---|---|---|
| ProFlex 680E | One-component solvent-based | General waterproofing, roofs, cold weather, damp substrates |
| ProFlex 2K | Two-component | Industrial floors, chemical resistance, heavy abrasion |
Q2: Can ProFlex 680E be applied over existing coatings?
Yes, but test adhesion first. Old coatings must be sound, clean, and compatible.
Q3: How is it different from epoxy?
| Feature | ProFlex 680E (Polyurethane) | Epoxy |
|---|---|---|
| Flexibility | High (500% elongation) | Low (brittle) |
| UV Resistance | Good | Poor (chalk quickly) |
| Chemical Resistance | Excellent | Excellent |
| Application Temperature | Down to -5°C | +10°C minimum |
Q4: Can I apply it in high humidity?
Yes—moisture-cure polyurethane actually needs humidity to cure. Ideal humidity: 40-80%.
Q5: How do I clean tools?
Clean immediately with xylene or acetone. Cured material must be removed mechanically.
Q6: What is the shelf life?
12 months in sealed, unopened containers. Store away from moisture and ignition sources.
Q7: Is it suitable for potable water tanks?
No—use our AQUAFLEX 590 ECO or NSF-certified ProFlex 2K for drinking water.
Q8: Can it be applied in direct sun?
Yes, but avoid extreme heat (>40°C) which may cause solvent blistering. Apply in early morning or late afternoon.
10. Case Study: Industrial Roof in Northern Canada
Project: 10,000 m² food processing plant roof, Yellowknife, Canada
Climate: Winter temperatures down to -40°C, summer to +25°C, freeze-thaw cycles
Problem: Existing EPDM membrane was failing at seams, causing leaks
Solution: ProFlex 680E applied over prepared concrete deck (2 coats, 500 microns total)
Results:
No leaks after 5 years
Survived -40°C winters without cracking
Maintenance staff can walk on roof for equipment access
Reflective topcoat reduced summer cooling costs
11. Quality Assurance and Certifications
ProFlex 680E is manufactured to meet international standards:
| Certification | Scope |
|---|---|
| ISO 9001 | Quality management system |
| ISO 14001 | Environmental management |
| ASTM C836 | Standard for cold liquid-applied elastomeric membranes |
| AASHTO M 316 | Bridge deck coating standard |
| LEED v4 | Contributes to MR credits |
Contact us for specific project certifications.
12. Conclusion and Call to Action
ProFlex 680E is the professional’s choice for waterproofing in extreme weather conditions. Its solvent-based, moisture-cure chemistry delivers:
Low-temperature application (down to -5°C)
Flexibility at -30°C—no cracking
Deep penetration into concrete substrates
Excellent adhesion even on damp surfaces
UV resistance (with proper topcoat)
Whether you need to protect:
Industrial roofs in cold climates
Bridges exposed to de-icing salts
Chemical plants with aggressive exposure
Coastal structures facing salt spray
ProFlex 680E delivers uncompromising performance where ordinary coatings fail.
Ready to specify or purchase?
- Contact Information: WhatsApp: +86-13153030995 E-mail: info@ylc-waterproofing.com