Harpenden, United Kingdom

Sika supplied a single-source warranty as part of a dual waterproof solution for a large, privately-built concrete basement to guarantee its long-term protection against the perils of damp and water ingress.

The 153m2 basement was part of a new build house in Harpenden, Hertfordshire. A toilet, cinema room, games room and a plantroom are earmarked for the below-ground structure; therefore its long-term resistance to water ingress was paramount.

Project Requirements

The client required a concrete waterproofing system that not only offered optimum protection against flooding and other damp-related issues but was also accompanied by a single-source, 15-year warranty. Sika was able to comfortably satisfy both requests.

Sika Solutions

The first waterproofing element was contained in the concrete, with Sika® Watertight Concrete added to the concrete mix as an additive. An integral system, Sika® Watertight Concrete is the most widely-used waterproofing solution in the UK due to its inherent buildability, repairability and reduced cost. State-of-the-art Sika admixtures are added to the system to prevent water penetration.

The simple and rapid-apply Type B system is completed with carefully selected water-stops for construction and movement joints to produce a durable, fully-waterproof structure.

To compound the system’s waterproof properties, TK Waterproofing Solutions, the contractors selected by Tilsworth Development, applied Sika® BentoShield® MAX LM to retaining walls and under floor slabs throughout the structure. Comprising a factory prehydrated, needle punched and PE flexible membrane, the fully-bonded, self-healing product is ideal for basements and other below-ground structures that are exposed to aggressive ground conditions and stress, or spaces requiring a completely dry internal environment.

The sealing technology of Sika® BentoShield® MAX LM combines the unique swelling performance of sodium bentonite with high-strength polypropylene geotextiles. It forms a tenacious mechanical bond to freshly-poured concrete to fully-eliminate water tracking. For the basement’s walls, Sika® Drain-850 Geo, a dimpled drainage and protection sheet with filtration layer, provided a smart, high performance waterproof finish.

The basement’s waterproof concrete system was installed in three weeks. With the installation carrying a 15-year warranty the client is reassured the structure’s watertightness will remain as reliable and robust as the day Sika’s dual solution was implemented

"For peace of mind and guarantee of a high-quality concrete waterproof solution, the client required a dual system and a single source warranty. Sika provided a financially strong, credible option. The system itself offers strong, reliable results and is incredibly easy to apply. Upon completion, contractor and client were extremely pleased with the speed of the system’s application and its overall performance" Michael Maxey, Operations Manager at TK Waterproofing Solutions

Project Participants

TK Waterproofing Solutions