Tank waterproofing

Tank Waterproofing Solutions for Concrete and Steel Tanks

 Water storage and process tanks are exposed to some of the harshest operating conditions in commercial, industrial, municipal, and agricultural environments. Whether a tank stores potable water, wastewater, chemicals, fire protection water, or industrial process liquids, it must withstand continuous moisture, hydrostatic pressure, temperature fluctuations, and, in many applications, aggressive chemical exposure. Without an appropriate waterproofing and protective lining system, these conditions can lead to water ingress, corrosion, concrete deterioration, contamination, and costly structural repairs. Over time, even minor defects can develop into significant maintenance issues that affect both the performance of the tank and the surrounding infrastructure.

 At Alka Coatings, we provide complete tank waterproofing solutions for concrete, steel, and fibreglass tanks across Australia. From new construction to refurbishment projects, our systems are selected to match the operating environment, substrate condition, and long-term performance requirements. By combining quality products with proper surface preparation and professional installation, we help clients extend asset life while reducing maintenance costs and operational downtime.

A successful waterproofing system creates a durable barrier between the stored liquid and the tank structure. This barrier helps prevent leakage, protects concrete and steel from corrosion, and maintains the integrity of the asset throughout its service life. Modern tank waterproofing systems may include cementitious waterproofing membranes, epoxy linings, polyurethane coatings, polyurea membranes, or specialist chemical-resistant coatings. The most appropriate system depends on several factors, including:

 Type of liquid being stored;

Concrete, steel, or fibreglass substrate

Continuous or intermittent immersion

Chemical exposure

Operating temperature

Abrasion and mechanical wear

Cleaning and maintenance procedures

Required service life

 Because every application is different, selecting the correct waterproofing system requires technical assessment rather than simply choosing a standard waterproof coating. Tank waterproofing is used across a wide range of industries where long-term protection against moisture and chemical exposure is essential. Common applications include:  Potable water storage tanks , Fire water tanks , Wastewater treatment tanks , Sewerage infrastructure , Neutralising tanks , Chemical storage tanks ,Process water tanks , Agricultural water storage tanks , Irrigation , reservoirs , Aquaculture and fish hatchery tanks , Concrete reservoirs , Steel storage tanks , Bunds and secondary containment areas ,Pump stations , Clarifiers and digesters , Sumps and pits , Industrial processing facilities.

 Although these structures all retain liquids, the performance requirements can vary significantly. A potable water tank requires coatings suitable for contact with drinking water, while wastewater and chemical storage tanks demand specialist linings capable of resisting aggressive chemicals, biological activity, and continuous immersion. For this reason, waterproofing systems should always be selected based on the specific operating conditions rather than using a one-size-fits-all approach.

 Concrete Tank Waterproofing

 Concrete is widely used for constructing water-retaining structures because of its strength and durability. However, concrete is naturally porous and can absorb water over time if left unprotected. Cracks, construction joints, honeycombing, and shrinkage can all create pathways for moisture penetration, allowing water and contaminants to reach the reinforcing steel. An effective concrete tank waterproofing system begins with a thorough assessment of the substrate. Before any coating is applied, damaged concrete should be repaired, surface defects removed, and cracks treated using suitable repair methods. Surface preparation is critical, as coating performance depends on achieving a clean, sound, and properly profiled substrate.

Depending on the operating environment, concrete tanks may be protected using:

 Cementitious waterproofing systems

Flexible waterproof membranes

High-build epoxy linings

Polyurethane waterproofing coatings

Polyurea protective membranes

Chemical-resistant epoxy systems

Steel Tank Waterproofing

Steel tanks require a different approach to waterproofing because corrosion can begin as soon as moisture reaches exposed steel surfaces. Continuous immersion, condensation, oxygen, and aggressive chemicals all contribute to corrosion if the substrate is not adequately protected. Successful steel tank protection starts with surface preparation. Existing coatings, rust, mill scale, and contaminants should be removed using appropriate abrasive blasting methods to achieve the surface profile recommended for the selected coating system.

Once prepared, steel tanks are typically protected using high-performance epoxy, polyurethane, or polyurea coating systems that provide excellent adhesion, corrosion resistance, and long-term durability. For highly aggressive industrial environments, specialist novolac epoxy or glass flake reinforced coatings may be specified to improve chemical resistance and abrasion performance.

Special attention should also be given to welds, bolts, edges, penetrations, and difficult access areas. These locations are more susceptible to premature coating failure and are commonly treated with stripe coats before the full coating system is applied. A well-designed protective lining system not only prevents corrosion but also reduces maintenance requirements and extends the operational life of valuable steel assets.

Alka 100 | 2-componenet, 100% solid, clear & transparent epoxy resin | Excellent Levelling

Alka 111 | 2-component, high chemical resistance Novolac Epoxy floor Coating | Novolac

Alka 310 | 1-component, low VOC, moisture-curing, elastomeric waterproofing membrane

Alka 311 | 2-components, VOC-free, quick-curing, elastomeric PU waterproofing membrane

Alka 312 | 1-component, low VOC, moisture-curing, elastomeric waterproofing membrane

Alka 801 | 2-components, spray-in-place, solvent-free, flexible & 100% solids polyurea elastomer

Alka 802 | 2-components, spray-in-place, solvent-free, flexible & 100% solids polyurea elastomer

Alka 412 | 2-Components, Surface Tolerant Epoxy

Alka 413 | MIO Epoxy Coating System

Alka 414 | Glass Flake Epoxy Coating System