In Medieval Europe, security was of utmost importance. In situations where castles, forts, or towns lacked elevation or natural land features for protection, water-filled moats were employed as a defensive measure. Medieval engineers traditionally used lime plaster and/or a bitumen emulsion (sometimes mixed with horsehair) to waterproof these foundations from the water occupying moat. Another method utilized by engineers was the use of lead plates in conjunction with the bitumen emulsion to provide added protection against water ingress from the moat.
Bitumen was a viable waterproofing solution for foundations until the 1900s, when a more dependable “liquid” bitumen became commercially available. Rubber and resin waterproofing solutions dominated the industry until the mid-1900s, however, in pursuit of increasing the durability and quality of the waterproofing membrane, synthetic materials made their debut.
Waterproofing manufacturers in the 1960s and 1970s developed and implemented what they believed were the next generation of waterproofing solutions. Materials such as styrene butadiene, polyester varieties, acrylic, and acrylic emulsion were being used by the industry to enhance and increase application rates in below-grade waterproofing. Today, waterproofing commercial buildings typically consists of liquid- or sheet-applied materials that are derived from asphalt, bitumen, and plastic-type raw materials. Foundation waterproofing has advanced over thousands of years; however, construction materials and techniques have fundamentally changed since the laying of the first foundation stone of the great Pyramid of Giza.
Despite the vast knowledge and extensive history of waterproofing materials and techniques, there are still basic failures in waterproofing that persist daily. To mitigate the risk of in-situ waterproofing failures, it is crucial for the materials to address four key elements of operation: ease of full application, resistance to damage, monolithic protection, and a high level of chemical resistance. There are many variables that can lead to a waterproofing system failure, and removing some of these key problematic variables can contribute to a higher success rate in performance.
According to Building Diagnostics Associates, a building diagnostic firm in Florida, their findings through surveys and reviews revealed that approximately 60 to 70 per cent of failures can be attributed to poor construction, 20 to 25 per cent to inadequate design considerations, and the remaining 10 per cent to non-performing materials.1
An insight on polyurea
With its exceptional durability and versatility, polyurea serves as a reliable solution that can be applied on-site, bridging the gap between subpar construction practices and insufficient design considerations. As a spray-applied membrane, it offers an efficient and effective means of achieving long-lasting waterproofing protection.
The construction industry has come a long way from the basic application of foundation waterproofing through brushes, buckets, and nose plugs. The modern waterproofing movement is directed toward resilient, free of volatile organic compounds (VOCs) and asphaltic, monolithic, high-performing resins, whether the advanced formulation is polyurethane or polyurea.
