Gilsonite in Waterproofing: An Overview

Water is the main enemy of buildings and infrastructure. Bituminous waterproofing materials are widely used, and gilsonite improves many of them.

Why gilsonite

• Very low water absorption
• Raises softening point and hardness of bitumen
• Reduces flow on vertical surfaces
• Improves adhesion

Products

• Roofing compounds and coatings
• Foundation dampproofing
• Bridge deck membranes
• Tank and reservoir linings
• Bituminous membranes

How gilsonite changes a bituminous compound

Ordinary penetration-grade bitumen is soft at summer roof temperatures and can flow on vertical surfaces. Adding a few percent of gilsonite raises the softening point and lowers penetration, so the compound stays in place without becoming brittle when blended correctly.

Exact values depend on the base bitumen, so always run a small dosage series in the lab.

Choosing a system

• Solvent-based coatings penetrate porous concrete and dry quickly.
• Emulsions are low-odour and suitable for indoor or confined areas.
• Hot-applied compounds and membranes give the thickest, most durable layers.

Common mistakes

• Applying on damp or dusty surfaces, which causes blistering and poor adhesion.
• Using too much gilsonite without flexibilizers, making the film crack on moving substrates.
• Skipping primer on porous concrete.

See coating and waterproofing grade gilsonite and foundation waterproofing.