leakage detection and repair solutions designed to stop damage at its source. Our team ensures fast, reliable, and long-lasting fixes that protect both your water system and building structure.

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Common Causes of Water Tank Leakage: Know The Cause Before The Cure

  • Unsealed Construction Joints: They are the most common point of failure in both overhead and underground tanks. The space between the floor slab and walls was never sealed. 
  • Shrinkage Cracks: As concrete cures, it shrinks slightly. In tanks, the weight and pressure of the water stored cause these hairline cracks to open further. 
  • Pipe Entry Points: Inlet, outlet, and overflow pipes pass through tank walls and are weak points where water can escape if the seal fails. 
  • Age and Chemical Attack: Standard concrete degrades slowly in municipal water supplies, but chlorine in the water accelerates the process, and tanks over 10 years old are much more vulnerable.
  • Poor Original Waterproofing: Many tanks in Pakistan were built without an internal waterproofing membrane, relying only on dense concrete.

How We Repair Water Tank Leakage: Every Step to Fix the Problem from the Root

Drain and check: The tank is drained, and the interior surfaces are inspected for cracks, joint failures, and pipe penetration. We monitor the outside base and walls for moisture migration away from the building.

Surface Preparation: Removal of loose concrete, old coatings, and contaminated surfaces. Cracks are chased out, cleaned, and filled with either hydraulic cement or polyurethane injection resin, depending on whether the crack is active or dormant.

Waterproofing Application: We apply a certified, food-safe crystalline or cementitious waterproofing coating to all interior surfaces. These compounds actually penetrate the concrete matrix and permanently block water movement; they don’t just sit as a surface film that peels off.

Pipe Penetration Sealing: All inlet, outlet, and overflow entry points are resealed with flexible, waterproof compounds that allow minor pipe movement without cracking.

Refill and Leak Test: We refill the tank and monitor it before we close the job. If there’s any point weeping, it’s repaired before we leave.

Overhead vs Underground Tanks: Key Differences

Overhead tanks tend to leak downward, allowing water to seep into the roof slab, travel through the parapet walls, and stain or damage the ceiling of the room below. The main structural concern is the roof slab that supports the tank’s weight. When concrete gets wet and is under load, it loses its strength more quickly.

Underground tanks leak into the surrounding soil instead. In places like Lahore, Multan, and interior Punjab, where clay soil is prevalent, this added moisture can cause the soil to swell against the foundation walls, making any existing foundation or waterproofing issues even worse.

Both types of tanks require the same thorough internal treatment, but the external effects and the urgency of addressing them can differ.

Why Choose One Roof Waterproofing for Water Tank Repair?

  • Safe, potable water-compliant materials used
  • We fix the joint, not just the crack 
  • Same-visit roof inspection 
  • No temporary fixes 

Get Your Tank Fixed Before the Damage Spreads

Whenever a tank leaks, water ends up where it shouldn’t be. If you need help, just reach out to One Roof Waterproofing for a free inspection and a precise quote, no estimates or unclear pricing involved.

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