Pasco 121 Cementitious Waterproof Membrane

Product Description

The PASCO 121 is a one-component cementitious waterproof membrane designed for a broad range of positive and negative waterproofing applications. Built on advanced cross-linking polymer technology, this standalone flexible polymer cementitious membrane requires only the addition of water to form a high-quality liquid membrane slurry. No separate liquid additive is needed. The cured film produces a watertight barrier that remains permeable to vapor diffusion, resists frost and long-term aging, and delivers strong adhesion to concrete, masonry, and mineral substrates. Plumbers, waterproofing contractors, and pool service professionals rely on it for both interior and exterior installs.

The PASCO 121 is suited for residential and commercial waterproofing projects across a wide variety of substrates and environments. Typical applications include water features, pools and ponds, potable water tanks, internal and external walls, planter boxes, lift pits, and retaining walls. Its flexibility and single-component mixing process make it practical for both new construction and remedial waterproofing work where substrate access and prep time are limited.

Key Features

• Single-component formula: mix with water only, no liquid additive required
• Suitable for both positive and negative waterproofing applications
• Flexible polymer cementitious composition for crack-bridging performance
• Cured membrane is permeable to vapor diffusion, reducing hydrostatic buildup risk
• Excellent resistance to frost and long-term aging
• Strong adhesion to concrete, masonry, and mineral substrates

Compatibility

Designed for application over concrete, masonry, and mineral substrates in both interior and exterior waterproofing installations, including potable water tank linings, pool and pond structures, retaining walls, planter boxes, and lift pits.

Installation Notes

Application is typically performed by licensed waterproofing contractors or plumbers, depending on jurisdiction and project scope. Substrates should be clean, sound, and free of standing water, oils, or loose material before mixing and applying the slurry. Follow all applicable local building codes and manufacturer mixing ratios when preparing the product. Allow each coat to reach the appropriate cure stage before applying subsequent coats or covering the membrane.

Technical Specifications

• Component Type: One component, water-mixed cementitious membrane
• Base Technology: Advanced cross-linking polymer
• Substrate Compatibility: Concrete, masonry, mineral substrates
• Waterproofing Type: Positive and negative
• Vapor Permeability: Permeable to vapor diffusion

Standard Information

• Brand: PASCO
• Manufacturer Part Number: 121