Description

About Sika Thoroseal 581

Sika Thoroseal 581 is a heavy-duty, Portland cement-based coating designed for waterproofing and protecting concrete and masonry structures. Originally known as Thoroseal, this material forms a durable, structural bond with the substrate to seal out water while allowing the surface to breathe. It is formulated to fill and seal voids in poured concrete, block, brick, and stone, providing a functional and aesthetic finish. The product is supplied as a powder that is mixed with water or a specific acrylic admixture prior to application. It is suitable for use on both interior and exterior surfaces, as well as above and below-grade applications.

Sika Thoroseal 581 Technical Specifications

• Material Composition: Portland cement, graded sand, and proprietary chemicals
• Packaging: 50 lb Bag
• Color: Gray
• Permeability: Water vapor permeable (breathable)
• Certifications: NSF/ANSI 61 approved for contact with potable water
• Service Environment: Interior, Exterior, Above Grade, Below Grade

Applications & Material Features of Sika Thoroseal 581

Sika Thoroseal 581 is utilized by professionals for waterproofing basements, foundations, retaining walls, and water cisterns. Its composition allows it to bond mechanically and chemically to porous substrates, effectively becoming part of the wall. The coating is resistant to hydrostatic pressure and helps protect masonry from environmental dampness. Key material features include:

• Adheres successfully to concrete, brick, block, stone, and cured stucco
• Resists positive and negative side hydrostatic pressure
• Allows trapped moisture to escape without compromising adhesion
• Compatible with brush or spray application methods
• Provides a uniform texture and appearance to masonry surfaces