Water tank waterproofing for duplexes in Aldarb

Prepared by the technical team · editorial review · last updated 13 November 2026 · Sources

Why water tank waterproofing differs in Aldarb

The centre of Aldarb sits about 79 m above sea level (SRTM open elevation data). Aldarb is about 18.7 km from the sea coast (OpenStreetMap).

Picture a duplex owner in Aldarb who has noticed a damp patch spreading across the ceiling of the upper unit, while the rooftop water tank has started to show a faint stain near its base. The household uses the tank daily, the rooftop is the first place rain and sun reach, and nobody wants to pay for repairs twice. This owner wants a clear plan that protects both the tank and the roof below it, without guessing at what the work will cost.

The local facts shape that plan. The centre of Aldarb sits about 79 m above sea level, and the town is about 18.7 km from the sea coast, so it is an inland setting rather than a coastal one. For a duplex, that means rooftop and tank waterproofing matter just as much as ground-level work, because heat and rain stress the exposed surfaces above the living space. Liquid roof waterproofing typically falls in the SAR 8–25 per m² range, bitumen membrane in SAR 15–35 per m², and XPS boards in SAR 12–30 per m². For the tank itself, tank internal coating is priced at SAR 25–60 per m², which is worth checking early because interior coating is often what stops leaks from reaching the water supply.

Start by inspecting the tank and the roof together, marking every crack and wet area. Next, measure the roof and the internal tank surfaces so you can compare quotes on the same basis. If cracks run through the concrete, crack injection is usually priced at SAR 40–120 per metre, so measure their length before deciding on the method. Then choose the roof system, weighing liquid coating against bitumen membrane for your roof's condition. Clean and dry every surface before any product goes on, because adhesion decides how long the work lasts. Finally, inspect the finished work after the first rainfall and keep a record of the measurements and product used for future maintenance.

In a duplex, the two floors often share lines, so tests are done floor by floor.

Signs that call for water tank waterproofing

If you notice one of these signs in Aldarb, it is a good moment to talk to the team:

• Unusual colour or taste in the water
• A tank that leaks after testing
• Deposits and flaking inside the tank

The most common causes

• Construction joints — we check this before anything else.
• Damaged old coating — we check this before anything else.
• Cracks in the walls or floor — we check this before anything else.

Tools and methods, and when we use them

How the work is done, step by step

1. Emptying and ventilation: The tank is emptied and ventilated before entry.
2. Cleaning and preparation: Loose material is removed down to a sound surface.
3. Crack treatment: Active cracks are treated first.
4. Coating layers: A material intended for drinking-water tanks is applied.
5. Disinfection and fill test: The tank is disinfected and the level is monitored after filling.

Aldarb in facts and sources

Short answers for Aldarb

Common mistakes we see

• Using a material that is not intended for drinking water

What you get after the work

You receive: the material name, its batch number and the fill-test result, in a technical report with a verification code.