Water tank waterproofing for schools in Najran

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

Water tank waterproofing in Najran: the local context

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.. Main roads in or near Najran: Al Jarba Street.

The centre of Najran sits about 1309 m above sea level (SRTM open elevation data).

The typical owner of a school in Najran is a school administrator or facilities manager who looks after a building with several rooftop or ground-level water tanks. Their days are busy with students, staff and timetables, so water problems often appear quietly: a damp patch on a classroom wall, a slow leak from a tank, or a stain spreading across a ceiling near the washrooms. By the time the problem is visible, the tank may have been losing water for some time, and the repair has become larger than it needed to be.

Najran sits at a high elevation, about 1309 m above sea level, which means the air can be drier than at the coast, yet sudden heavy rain still falls on flat roofs and runs toward tanks and drains. For a school, this matters because tanks often sit on open roofs exposed to sun, wind and rain. Sun heats the tank walls and can weaken old coatings, while rain washes over joints and cracks. A school owner should therefore check the tank's inner surface and its roof area on a regular basis rather than waiting for a leak to appear in the classrooms below.

A practical approach starts with inspection. First, empty the tank safely and look for cracks, flaking coatings, and damp joints. Second, decide the scope: the roof area may need liquid waterproofing, which is commonly priced at SAR 8–25 per m², while the tank interior may need a coating at SAR 25–60 per m². Third, seal any visible cracks by injection, which is charged at SAR 40–120 per metre. Fourth, where a bitumen membrane or XPS boards are used for insulation or protection, obtain quotes at the stated ranges, and confirm the area measured on site. Finally, schedule follow-up checks after heavy rain so that any remaining weak points are found early and the school keeps its water supply clean and dependable.

For schools, the larger jobs are planned for weekends and holidays.

Signs that call for water tank waterproofing

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

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

Causes we see in the field

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

Tools we use in Najran

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 — Najran

Questions from Najran

What we advise against

• 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.