High-Performance Polyurethane Waterproof Coating for Long-Term Structural Protection

Underground structures such as basements, foundations, tunnels, and underground parking garages are constantly exposed to groundwater pressure and soil moisture.

Without a reliable waterproofing system, water infiltration can cause:

• Concrete cracking
  
• Steel corrosion
  
• Structural deterioration
  
• Mold and leakage
  
• Expensive long-term repairs
  

For underground engineering projects, polyurethane waterproof coating is one of the most effective and durable solutions available today.

Why Underground Structures Require Advanced Waterproofing

Unlike exposed roofs, underground waterproofing must withstand:

• Continuous hydrostatic pressure
  
• Long-term water immersion
  
• Structural movement
  
• Soil settlement
  
• Temperature variation
  

Traditional cementitious coatings often crack under movement. Sheet membranes may fail at seams.

A liquid-applied polyurethane waterproof coating forms a seamless, flexible, and highly durable waterproof barrier — ideal for underground applications.

TW331 Polyurethane Waterproof Coating

Engineered for Non-Exposed Underground Applications

TW331 is a high-solids, single-component oil-based polyurethane waterproof coating specially designed for:

• Basement waterproofing
  
• Foundation wall waterproofing
  
• Underground tunnel protection
  
• Bridge deck waterproofing (non-exposed)
  

It forms a continuous waterproof membrane without joints or weak points.

Technical Performance Designed for Underground Conditions

TW331 provides exceptional mechanical and waterproofing properties:

• Solid Content: 87.8%
  
• Elongation at Break: 612%
  
• Tensile Strength: 2.17 MPa
  
• Tear Strength: 16 N/mm
  
• Adhesion Strength: 1.2 MPa
  
• Water Absorption Rate: 2.0%
  
• Water Permeability Test (0.3MPa, 120min): PASS
  
• Aging Test After Heating: PASS
  

These performance indicators are critical for underground waterproofing systems exposed to constant moisture and pressure.

Key Advantages for Basement & Foundation Waterproofing

TW331 forms a seamless, monolithic waterproof membrane without joints, eliminating the weak points typically associated with sheet systems. With an impressive 612% elongation at break, it delivers outstanding crack-bridging capability, allowing the coating to accommodate structural movement and minor settlement without compromising waterproof integrity. Its strong adhesion strength of 1.2 MPa ensures a firm bond to concrete substrates, effectively preventing water migration beneath the membrane. In addition, the high solid content of 87.8% contributes to a thicker cured film, reduced shrinkage, and enhanced long-term durability. The coating has also passed water permeability testing under 0.3 MPa pressure for 120 minutes, demonstrating reliable resistance against groundwater pressure in demanding underground applications.

Why Polyurethane Waterproof Coating Outperforms Traditional Systems

For underground engineering, seamless liquid-applied polyurethane systems provide greater long-term reliability.

Recommended Application Process for Underground Projects

• Surface preparation (cleaning and repairing cracks)
  
• Apply polyurethane waterproof coating evenly
  
• Allow skin formation (approx. 6 hours)
  
• Allow full curing (heavy traffic approx. 10 hours)
  
• Apply protective layer before backfilling
  

Proper installation ensures maximum waterproof performance and durability.

Long-Term Structural Protection Starts Underground

Waterproofing failures often originate in basement and foundation areas.

By selecting a high-performance polyurethane waterproof coating, contractors and developers can:

• Prevent costly water damage
  
• Extend building service life
  
• Improve structural safety
  
• Reduce maintenance costs
  

TW331 provides a reliable and durable waterproofing solution engineered specifically for underground construction.

Contact Person: Tina

Phone No.: 0086-18596167593

WhatsApp: 0086-18596167593

EMAIL：tina@sdsealant.com