Basement & foundation waterproofing for duplexes in Allith

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

Before we start: what we know about Allith

Main roads in or near Allith: Al Laith Road, Amr Bin Al Aas Street. The centre of Allith sits about 5 m above sea level (SRTM open elevation data).

Allith is about 1.2 km from the sea coast (OpenStreetMap).

Allith sits about 5 m above sea level, and its centre is roughly 1.2 km from the sea coast. Those two facts shape the first checks for any basement or foundation job on a duplex here. Because the ground is low and close to the sea, the technician looks first at how water is likely to move toward the lower walls and slab, and whether the foundation has been exposed to moisture for long periods. Where a basement is involved, the first questions are about the state of the lowest walls and the base joint, since that is where seepage usually starts.

Some things can only be judged on the site visit. The exact depth of the basement, the condition of the existing membrane, the size and direction of any cracks, and how much water reaches the wall after rain all need to be seen and measured in person. The technician will also decide whether the work calls for a surface coating, a bitumen membrane, rigid XPS boards, or crack injection. Pricing depends on the surface area and on the length of cracks found, so the rate for basement waterproofing (SAR 50–150 per m²) and for crack injection (SAR 40–120 per metre) can only be applied once those figures are known. Epoxy coating (SAR 35–90 per m²) and spray foam (SAR 20–45 per m²) are also options that depend on what the wall condition shows.

For the technician, it helps to know whether the duplex shares a boundary wall, whether the basement is used for storage or living space, and whether any bathroom or roof work is planned at the same time. Bathroom waterproofing runs at SAR 15–40 per m², liquid roof waterproofing at SAR 8–25 per m², and a tank internal coating at SAR 25–60 per m², so bundling jobs can be discussed on the same visit. Please note where any past leaks have appeared, what finishes are already in place, and whether the owner has noticed damp after heavy rain. This information lets the technician plan access, materials and time before arriving on site.

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

When do you need basement & foundation waterproofing?

The following signs are worth checking before they grow:

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

The most common causes

• Cracks at construction joints — we check this before anything else.
• Rainwater draining towards the foundation — we check this before anything else.
• A common cause: a high groundwater level.

How we choose the tool in Allith

From the first visit to the report

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 — Allith

Short answers for Allith

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.