Below-Grade Waterproofing Membranes, Primers, and Accessories

Below-grade structural waterproofing is necessary for preventing costly water damage to any part of the building below ground level. Appropriate waterproofing products and systems are needed to protect below-grade concrete structures like basements, underground parking, and foundation walls from water infiltration.

Polyglass’ range of structural waterproofing systems includes pre- and post-applied waterproofing membranes, and accessories for horizontal and vertical applications. Our solutions cover a wide range of technologies to meet varying designs and specifications for below-grade foundations, split slabs, and elevated plaza deck applications.

Explore our below-grade waterproofing products below.

Why Does the Below-Grade Structure Need Waterproofing?

Below-grade building structures are particularly susceptible to water and moisture damage if not appropriately waterproofed during construction.

Water infiltration can weaken below-grade structures by corroding reinforcing steel. For example, dissolved salts and chemicals found in water can have a degrading effect on concrete foundation slabs, walls, and steel.

Polyglass’ below-grade waterproofing products and systems have been uniquely designed to prevent water infiltration and lateral water migration below grade. They are also highly resistant to harmful chemicals and natural salts found in ground and surface water.

Waterproofing Membranes for Below-Grade Applications

Polyglass’ post-and pre-applied waterproofing membranes are suitable for horizontal underslab and vertical blindside applications.

Our below-grade waterproofing membranes use high-density polyethylene (HDPE) or a combination of woven and nonwoven polypropylene (PP) geotextile fabrics and sodium bentonite clay.

HDPE is an ideal waterproofing material for below-grade structures. It offers a high strength-to-density ratio, resistance to naturally-occurring chemicals found in soil, and is impervious to water, acids, solvents, and common chemicals. Sodium bentonite expands when wet to form a single waterproofing membrane, while PP is known for its chemical resistance, elasticity, toughness, and fatigue resistance.

Solvent and Water-Based Waterproofing Primers

Water- or solvent-based adhesive primers like Mapeprime™ S710 and Mapeprime™ 720 W are used for improved adhesion of Polyglass’ self-adhered waterproofing membranes to a range of prepared substrates.

Below-Grade Waterproofing Accessories

Various Polyglass accessories are available for below-grade waterproofing, including

  • Liquid membrane for detailing of both pre and post-applied systems, such as terminations and penetrations through slabs and walls.
  • Pressure-sensitive detail tape that bonds to pre-applied waterproofing membranes, ensuring watertight details.
  • Bentonite granules for detailing with PP waterproofing membranes.
  • Drainage mats or boards help channel water away from installed waterproofing systems and relieve backfill and hydrostatic pressure.

Related Resources

Why Polyglass?

Polyglass® is an ISO 9001:2015 Certified, leading manufacturer of modified bitumen roofing and waterproofing membranes and roof coatings for low- and steep-slope applications. We are an industry leader in self-adhered underlayments that are specially designed to help contractors save time and labor costs.

Utilizing the most technologically advanced manufacturing process in the industry, Polyglass operates six state-of-the-art manufacturing facilities — five in North America and one in Italy that serves all of Europe.

As a company that prides itself in innovative and quality roofing products that exceed the needs and expectations of its customers all around the world, we offer roofing contractors the following benefits:

  • An extensive line of underlayments and other roofing products that allow for custom-designed solutions for unique construction challenges and environmental conditions
  • Outstanding technical support and project assistance
  • The most trusted warranties in the industry
  • A registered contractor program and a wide array of contractor resources, including instructional videos to Polyschool courses.
  • The ability to earn points and redeem prizes for every Polyglass purchase with Club Premio

Evolving through innovation, Polyglass offers high-performance and exceptional quality Building Envelope Solutions. Our expert team is here to help you choose the best products and solutions for your next below-grade waterproofing project. Get in touch today.

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