Water tank waterproofing in Al Mrwj, Riyadh: emergency

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

Before we start: what we know about Al Mrwj

The centre of Al Mrwj is at 24.7578, 46.6637, about 5 km from the centre of Riyadh, with an approximate radius of 2.1 km. The service-area circle on the map below is drawn from this point. Al Mrwj has both villas and apartment buildings.

The centre of Al Mrwj sits about 635 m above sea level (SRTM open elevation data). Main roads in or near Al Mrwj: King Fahd Road, Northern Ring Road, King Abdulaziz Road.

The nearest wadi channel is about 2.8 km from the centre of Al Mrwj (OpenStreetMap).

Consider a homeowner in Al Mrwj, Riyadh, who wakes to find water dripping through the ceiling of a villa or an apartment flat, or notices damp patches spreading across a basement wall. The rooftop water tank may be leaking into the slab below, and the household needs the problem contained before it spreads. In a rush like this, the first instinct is often to call the first number found online, but a clear plan protects both the property and the budget.

The local facts shape how this emergency should be handled. Al Mrwj is about 5 km from the centre of Riyadh, with its centre at 24.7578, 46.6637, and it sits roughly 635 m above sea level. It has both villas and apartment buildings, so an owner may be dealing with a rooftop tank above a shared building or a single household's own roof. The nearest wadi channel is about 2.8 km from the centre of Al Mrwj, which is a reminder that heavy rain can move water quickly across the surrounding ground, so drainage around the building matters as much as the tank itself.

Start by switching off the tank supply valve and the pump if the leak is severe, and move furniture and electrical items away from the wet area. Photograph the damage and note where the water appears, since this helps any technician find the source. Next, identify whether the leak comes from the tank walls, the tank floor, the pipe connections or the roof beneath the tank, because each calls for a different fix. For tank internal coating, budget in the range of SAR 25–65 per m², and for the roof beneath, liquid roof waterproofing typically falls within SAR 10–25 per m². For cracks in the structure, crack injection is priced at SAR 40–125 per metre. Ask any contractor for a written quote that states the area measured, the materials and the scope, and confirm that the work will be completed before the tank is refilled. Finally, once the emergency is under control, arrange a planned review of the whole roof and basement so that any remaining weak points are sealed before the next rainy season.

If water is flowing, close the main valve first, then call or message with photos.

Signs worth paying attention to

The following signs are worth checking before they grow:

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

Where the problem usually comes from

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

Quick comparison: facts and costs in Al Mrwj

Common questions about water tank waterproofing in Al Mrwj

Mistakes that cost more

• 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.