Water tank waterproofing in Najran: preventive periodic check

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

Before we start: what we know about Najran

Main roads in or near Najran: Al Jarba Street. The centre of Najran sits about 1309 m above sea level (SRTM open elevation data).

Team note on Najran: 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..

The centre of Najran sits about 1309 m above sea level (SRTM open elevation data), and that height shapes where a preventive check should begin. At this elevation the first thing a technician looks at on a water tank is the tank's internal surface and its seams, because the stored water is the main ongoing exposure. Start with the internal coating and any visible hairline cracks or lifting edges, then move to the joints where the tank meets its base and walls. Note any staining, soft patches, or areas where the old coating has chalked, since these show where moisture is already getting through. Record the condition before any work is priced, so the owner can see the reasons behind each recommendation.

Several items are left to the site visit itself, because they cannot be judged from a description. The technician should measure the actual affected area in square metres and the length of any crack in metres, since rates for tank internal coating, epoxy coating and crack injection are set by those measurements. The access route, the state of the tank lid, the condition of the inlet and overflow pipes, and whether the tank is in use during the visit all affect how the work is carried out. Where the tank sits in the building matters too, as a rooftop tank and a ground-level tank face different exposures. Ask the owner about the water source and any past repairs so the visit covers the history as well as the present state.

Information that helps the technician includes the material options already known for this kind of work, with their typical rates for planning. Tank internal coating typically falls in the range of SAR 25–60 per m², epoxy coating in the range of SAR 35–90 per m², and crack injection in the range of SAR 40–120 per m. Where the tank roof is exposed, liquid roof waterproofing sits at SAR 8–25 per m², and bitumen membrane at SAR 15–35 per m². XPS boards, at SAR 12–30 per m², are an option where insulation is also needed. Bring a notebook or a tablet, photograph each defect with a reference, and leave the owner a written summary that lists the measured areas and the recommended materials in plain terms.

Preventive checks follow a written schedule instead of waiting for a fault.

When do you need water tank waterproofing?

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

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

Where the problem usually comes from

• Cracks in the walls or floor — we check this before anything else.
• Damaged old coating — we check this before anything else.
• A common cause: construction joints.

Tools and methods, and when we use them

From the first visit to the report

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.

Najran in facts and sources

Questions from Najran

Mistakes that cost more

• Using a material that is not intended for drinking water

What you receive

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