Water tank waterproofing for duplexes in Qatif

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

What is specific about Qatif for water tank waterproofing

The centre of Qatif sits about 5 m above sea level (SRTM open elevation data). Qatif is about 2.5 km from the sea coast (OpenStreetMap).

Team note on Qatif: Kashf teams serve this city and its nearby districts with the same documented inspection standard: device-based leak detection without demolition, a written report, and a clear scope before any work begins..

Before any coating is chosen for a water tank in Qatif, the first thing to check is the tank's location relative to the coast, because it shapes how the surface is likely to behave over time. The centre of Qatif sits about 5 m above sea level, and the town is about 2.5 km from the sea coast. Those two facts mean that the air carries salt and moisture from the Gulf, and that rooftop and tank surfaces here are exposed to that humid, salty environment year-round. Our technicians therefore start by noting how exposed the tank is, whether it sits on the roof or at ground level, and how much water and salt have already reached the concrete. This first check tells us whether the surface needs a flexible membrane, a protective coating, or a more involved repair before any product is named.

Some points can only be settled on the site visit. The technician will need to see the actual condition of the tank walls, floor and lid, mark any cracks, and test whether the existing surface is sound enough to bond a new layer. The internal condition, the access route, the presence of old coatings, and whether the tank is still in use all change the approach. Pricing also depends on the measured area and the length of any crack to be injected, so these figures are confirmed on site rather than estimated from a distance. The technician will also confirm whether the work can be done without emptying the tank fully, and whether the duplex residents need to arrange temporary water supply during the job.

To help the technician arrive prepared, residents can share a few details before the visit: the age of the duplex, the approximate size and position of the tank, any past leaks or stains, and whether the tank was last cleaned or repaired. Photos of visible damage on the walls or lid are useful, as is a note of which floors and bathrooms share the same water supply. For reference on general rates, tank internal coating is typically SAR 25–60 per m², liquid roof waterproofing SAR 8–25 per m², bitumen membrane SAR 15–35 per m², and crack injection SAR 40–120 per metre. A final quote will follow the site survey.

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

When do you need water tank waterproofing?

These are the signs most often linked to water tank waterproofing:

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

Causes we see in the field

• Damaged old coating.
• A common cause: cracks in the walls or floor.
• Construction joints.

Tools and methods, and when we use them

The steps in order

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.

Facts and costs — Qatif

Questions from Qatif

Mistakes that cost more

• Using a material that is not intended for drinking water

What you get after the work

The written output: the material name, its batch number and the fill-test result. The report is numbered and can be checked with its verification code.