Basement & foundation waterproofing for duplexes in Aljumum

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

Basement & foundation waterproofing in Aljumum: the local context

The centre of Aljumum sits about 200 m above sea level (SRTM open elevation data). Team note on Aljumum: 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..

Water entering a basement is the most common problem we see in duplexes, usually showing up as damp patches along the lower walls, efflorescence (white salt deposits) on the concrete, or hairline cracks where the floor meets the wall. In a duplex, the lower unit often shares the foundation with the upper one, so a leak that starts below can soon affect both households and the shared structure. Early signs are worth acting on before the damp spreads into finishes and wiring.

Aljumum sits about 200 m above sea level, and that elevation shapes how we approach these jobs. Ground conditions and drainage across the area can vary block to block, so we look at how water moves around the foundation before choosing a method. Crack injection is priced at SAR 40–120 per metre, which suits isolated leaks, while a basement that is damp across a wide area may call for a full treatment such as a bitumen membrane at SAR 15–35 per m² or epoxy coating at SAR 35–90 per m². Where a basement is treated from the inside, an epoxy coating or spray foam at SAR 20–45 per m² can seal the surface without major excavation. Basement waterproofing as a whole is typically SAR 50–150 per m², and the final figure depends on the area and the extent of the damage.

Before the visit, it helps to have a few details ready. Tell us the approximate size of the basement and whether the damp is in one corner or all around the walls, and note when it appears, such as after rain or all year. Mention any cracks you have noticed and whether there is a bathroom or water tank in the lower level, since those need their own treatment. Share any previous repair work you know about. With these answers, we can prepare a clearer plan for your duplex before we arrive, so the visit focuses on confirming the cause rather than guessing at it.

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

Signs that call for basement & foundation waterproofing

The following signs are worth checking before they grow:

• 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 — we check this before anything else.
• A common cause: a high groundwater level.
• A common cause: cracks at construction joints.

Tools we use in Aljumum

The steps in order

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.

Facts and costs — Aljumum

Questions from Aljumum

Mistakes that cost more

• Painting the basement wall while the water comes from outside

What you receive

The written output: the source, the treatment and the follow-up result. The report is numbered and can be checked with its verification code.