Basement & foundation waterproofing for duplexes in Jubail

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

Before we start: what we know about Jubail

The centre of Jubail sits about 4 m above sea level (SRTM open elevation data). Jubail is about 0.9 km from the sea coast (OpenStreetMap).

Team note on Jubail: 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..

Does a duplex basement in Jubail really need waterproofing when the city sits so close to the coast? The answer is yes, and the local geography explains why. The centre of Jubail sits about 4 m above sea level, and the town is about 0.9 km from the sea coast. Those two facts mean groundwater and moisture-laden air can reach a shallow basement easily, so damp walls and floor seepage are common concerns for duplex owners here. Basement waterproofing is priced at SAR 50–150 per m², and crack injection at SAR 40–120 per metre, so the right scope depends on what the inspection finds rather than a single flat rate.

Our inspection for a duplex basement follows a clear sequence. First, the technician walks the full basement and marks every area showing staining, efflorescence, peeling paint or water tracks on the walls and floor. Next, cracks are measured and recorded, because linear cracks are often treated by injection while broader wet areas may call for a membrane or coating. The team then checks the junctions where the basement wall meets the floor slab and where any pipes or drains pass through the structure. Finally, they compare the findings with the upper floors, since a leaking bathroom above can look like a basement problem. The inspector then proposes a method for each zone, such as epoxy coating at SAR 35–90 per m², spray foam at SAR 20–45 per m², or a bitumen membrane at SAR 15–35 per m², and explains why each one suits that surface.

To make the visit productive, prepare a few things in advance. Clear shelving, stored boxes and any items against the walls so the technician can reach every surface. Note when you first saw dampness and whether it worsens after rain or during humid months, because timing helps identify the source. If the bathroom above the basement has been treated before, have the details ready, and if the building has a water tank nearby, mention whether it has ever been coated or cleaned. Keep access to the basement open and let the technician know if you need a written breakdown of costs before work starts.

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

When do you need basement & foundation waterproofing?

These are the signs most often linked to basement & foundation waterproofing:

• Damp basement walls
• Salt marks at the bottom of the walls
• Water seeping in after rain

The most common causes

• Rainwater draining towards the foundation.
• A high groundwater level.
• A common cause: cracks at construction joints.

Tools we use in Jubail

How the work is done, step by step

1. Finding the source: Groundwater, rain or a pipe — each needs a different treatment.
2. Preparation: Surfaces are cleaned and opened where needed.
3. Injection: Active cracks are injected.
4. Waterproofing layers: The system is applied on the right side of the wall where possible.
5. Follow-up: Readings are repeated after the treatment.

Jubail in facts and sources

Short answers for Jubail

Mistakes that cost more

• Painting the basement wall while the water comes from outside

What you receive

You receive: the source, the treatment and the follow-up result, in a technical report with a verification code.