Water tank waterproofing for duplexes in Jazan

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

What is specific about Jazan for water tank waterproofing

The centre of Jazan sits about 7 m above sea level (SRTM open elevation data). Jazan is about 1.9 km from the sea coast (OpenStreetMap).

Team note on Jazan: 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..

Jazan sits close to the Red Sea, with the centre of the city about 7 m above sea level and roughly 1.9 km from the coast. For a duplex owner, this combination means the ground is low, the air is humid and salt-laden, and rainwater and groundwater can gather near the foundations. Water tanks on roofs and at ground level are exposed to both sun and sea air, so their coatings need to resist salt and heat as well as leaks.

Because the city lies so low and so near the water, the practical effect on the service is that we check the tank's internal surface and its base joints first, since moisture and salt can work into them quickly. The tank internal coating is priced at SAR 25–60 per m², and its cost depends on the surface area and the condition of the old lining. Where the duplex has a basement, basement waterproofing at SAR 50–150 per m² is measured against the wall and floor area that touches damp soil. Crack injection at SAR 40–120 per metre is often used along joints and cracks before any wider coating is applied, because a small opening left alone will carry water into the structure.

Owners in this area often make the same few mistakes, and a good service avoids them. The first is coating a tank or wall without first cleaning off salt deposits and loose material, which stops the new layer from bonding. The second is choosing a cheap surface treatment for a damp basement when the underlying crack has not been sealed. The third is ignoring the roof, where liquid roof waterproofing at SAR 8–25 per m² or a bitumen membrane at SAR 15–35 per m² protects the rooms below from the same moisture that reaches the tank. Bathrooms also need attention: bathroom waterproofing at SAR 15–40 per m² stops water from passing into the walls shared with the rest of the duplex. Dealing with these points early keeps repairs smaller and the home drier.

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

Signs worth paying attention to

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

Where the problem usually comes from

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

Tools we use in Jazan

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.

Jazan in facts and sources

Questions from Jazan

What we advise against

• Using a material that is not intended for drinking water

The written outputs

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.