Waterproofing and protective coating of concrete tank interiors

Reinforced-concrete tanks, vessels and settling basins are in constant contact with water and aggressive media. Without a reliable internal coating the concrete gradually deteriorates: water penetrates the pores, washes out the cement matrix and causes corrosion of the reinforcement, while effluents and chemically active liquids accelerate the process. An internal coating solves two tasks at once — it ensures water-tightness and protects the structure from destruction.

Solution options

• Polymer-cement brush-applied compounds — applied by brush or trowel, penetrate the pores, work on a damp substrate; suitable for basins and process-water tanks, but with limited elasticity.
• Epoxy coatings — strong, chemically resistant, with high adhesion; where resistance to aggressive media and abrasion matters; require a dry substrate.
• Polyurethane coatings — elastic, bridge hairline cracks, resistant to water and moderately aggressive media.
• Penetrating (crystalline) waterproofing — penetrates the concrete pores and crystallises, densifying the structure from within and increasing the water-tightness of the concrete itself. Works both as a standalone solution for damp structures and as substrate preparation under a coating.
• Polyurea (spray-applied) — the most universal solution for large vessels (see below).
• Sheet and membrane materials — used less often for internal surfaces of vessels.

How to choose the material

For drinking water — compounds with sanitary-hygienic approvals; for aggressive effluents — chemically resistant ones (epoxy, polyurea); for moving structures and crack formation — elastic ones (polyurethane, polyurea).

Polyurea as a universal product

Polyurea is a two-component hot-spray coating. Its advantages for protecting the concrete of vessels, settling basins and tanks:

• seamless: a continuous membrane without joints over the entire geometry of the structure;
• fast cure: shortens the time to commissioning;
• high elasticity: bridges concrete cracks and deformations;
• resistance to water, many chemical media and abrasion;
• high adhesion to properly prepared concrete.

That is why polyurea is used for clean- and process-water tanks, treatment facilities and settling basins. In our range this is the material LASTIC-GUARD; see the application service in the Services section.

Installation features

1. Concrete preparation: dust removal, removal of the weak layer (grinding or shot-blasting), repair of cracks and voids, roughening.
2. Control of concrete moisture; for damp substrates — compatible primers.
3. Priming — a mandatory step for the coating to bond to the concrete.
4. Application: polyurea — spraying with special equipment; brush-applied and polymer compounds — per the technology in the specified number of layers.
5. Control of coating thickness and continuity, water-tightness check before commissioning.
6. Commissioning — after the coating reaches its working properties.

What to consider

The tank’s purpose (drinking or process water, effluents, chemicals), operating conditions (temperature, abrasion, structural movement), the state of the concrete and the ability to prepare the substrate. Related topic — internal corrosion protection of tanks.

STATERM selects the coating for the tank type and medium, supplies the materials and performs the works turnkey — from substrate preparation to handover. We work on sites across all regions of Uzbekistan. For a consultation and calculation: +998 90 918-81-88, Telegram or leave a request.