Below Ground Tanking

Below ground tanking waterproofing systems for basements, retaining walls, foundations, and lift pits across New Zealand. Approved applicators for Sikaproof and bentonite systems.

Below Ground Tanking

Below ground tanking is a waterproofing system designed to prevent water ingress into structures that sit below ground level — permanently protecting basements, foundations, retaining walls, and below-ground service areas.

Our Systems & Expertise

We work with trusted, industry-proven systems including:

  • Sikaproof membrane systems
  • Bentonite sheet membranes

These sheet membrane systems create a continuous barrier against groundwater and hydrostatic pressure. Our team understands the critical detailing required around joints, penetrations, construction seams, and service entries — all points where failures commonly occur if not installed correctly.

Where Below Ground Tanking Is Used

  • Basements
  • Retaining walls
  • Foundations and footings
  • Lift pits
  • Tunnels
  • Below-ground service areas

Why Specialist Installation Matters

Because these systems become permanently enclosed once installed, engaging an approved applicator is essential to ensure compliance, durability, and performance. Gunac brings 40+ years of waterproofing expertise and a thorough understanding of soil conditions, water tables, and structural design requirements.

Proudly servicing Auckland, Waikato, and Bay of Plenty.

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Our team covers Auckland, Waikato, Bay of Plenty, and Christchurch. Get in touch today.

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