Tank waterproofing

When it comes to water tank waterproofing, there is no room for error. Whether it’s a concrete tank, a cistern, or an underground reservoir, cracks and leaks can compromise structural safety, water quality, and operational reliability.

MPM offers high-performance tank waterproofing solutions designed for extreme conditions, aggressive liquids, and constant hydrostatic pressure. With over 70 years of experience in advanced materials, our systems are trusted by professionals across the globe.

Tank waterproofing solutions built for permanent water contact

Most waterproofing products are designed to shed rain. Tank waterproofing is a different challenge: the coating sits under continuous water pressure, often on the wrong side of the wall from a drainage point of view, and it can never be allowed to fail quietly.

The Starflex range is part of MPM’s wider family of cold-applied liquid waterproofing systems, built from the ground up to bond to damp or wet concrete and stay elastic through thermal cycling, structural movement, and sustained hydrostatic load. A cement tank waterproofing job doesn’t need a bone-dry substrate before work can even start.

Where a concrete tank waterproofing project needs a fully impermeable membrane under permanent water head, or an underground tank waterproofing job has to resist pressure pushing in from every side, the same cold-applied logic holds. No removal of existing failed layers where they’re sound. No flame, no hot-works permit. A cure that keeps moving even in cold or damp conditions. For potable water tank lining specifically, our STARFLEX HR hot-applied system is certified for direct contact with drinking water (Italian Ministerial Decree 174/2004, Certificate No. 2201174).

Where a wastewater or industrial tank is exposed to diluted acids, alkalis, and aggressive effluent, the chemical-resistant concrete waterproofing systems in the range are formulated to hold up rather than degrade over a normal service life. For cistern and reservoir restoration, that same overlay logic applies: existing bituminous or single-ply membranes generally don’t need to come out first, saving both excavation cost and programme time.

How Starflex compares to traditional sheet membranes at a glance

What goes into a tank waterproofing system, and why one product alone isn’t the answer

Waterproofing coating for water tank applications is a system problem, not a single-product purchase. Failures cluster at the details: pipe penetrations, expansion joints, curved walls, domed roofs. Far more often than across the flat plane of a wall.

That’s why the Starflex range is built as a complete envelope rather than a standalone coating:

• Primers that bond to damp concrete, metal, existing waterproofing layers, and practically any site substrate encountered in refurbishment work
• Elastic liquid membranes engineered for continuous immersion and dynamic movement, with genuine crack-bridging performance rather than a rigid film that eventually splits
• Protective coatings resistant to elevated temperatures, UV exposure, and concentrated chemical attack, relevant wherever a waterproofing compound for water tank also has to survive industrial cleaning regimes
• Detail solutions for pipe penetrations, upstands, vents, and the complex geometry that a sheet membrane struggles to seal continuously
• Low-VOC formulations across the range, keeping application safer in enclosed or partially ventilated tank interiors

Every system in the range is cold-applied. No naked flame, no hot-works permit. Installation is by airless spray, trowel, or roller depending on the geometry involved.

Our certifications

Applications: every tank type, every condition

MPM Starflex systems have been specified and installed across the full spectrum of water and industrial tank structures, applying the same barrier logic used in our foundation and basement waterproofing systems wherever hydrostatic pressure is pushing in from every side.

FAQs

Does a concrete water tank need special waterproofing, or will a standard coating work?

Standard coatings are usually designed for occasional wetting, not permanent immersion under hydrostatic pressure. A concrete water tank needs a system engineered for continuous water contact, crack bridging as the structure moves, and, for potable water, certification for contact with drinking water specifically.

Can a water tank be waterproofed while it’s still damp, or does it need to dry out first?

With cold-applied systems designed for this, yes. Standard sheet membranes generally require a dry substrate, which can hold up a project for weeks. A system bonded for damp or wet concrete removes that delay.

What makes a waterproofing product suitable for a wastewater or industrial tank rather than a standard water tank?

Wastewater and industrial tanks expose the coating to diluted acids, alkalis, and aggressive effluent rather than clean water. The lining needs chemical resistance built in, not just water resistance, to avoid degrading over the tank’s service life.

How is a tank waterproofing job usually carried out?

It normally starts with a technical consultation on substrate and exposure conditions, followed by a site survey where the geometry is complex, then a bespoke specification and installation by a trained, certified applicator, with documentation supplied at handover.