Basement & foundation waterproofing for duplexes in Aldarb

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

Before we start: what we know about Aldarb

The centre of Aldarb sits about 79 m above sea level (SRTM open elevation data). Aldarb is about 18.7 km from the sea coast (OpenStreetMap).

Before any material is chosen for a basement in Aldarb, the first check is the site's position, because it shapes how water moves underground. The centre of Aldarb sits about 79 m above sea level, and the town is about 18.7 km from the sea coast. Those two facts mean the ground is not a coastal low-lying plain, so the technician should not assume that a high water table is the default problem. Instead, the first question is how rainwater runs off the plot and whether it collects against the lower walls of a duplex basement. Checking the slope of the ground around the building, the drainage outlets, and any signs of seepage at the wall base comes before pricing any coating, since the right system depends on where the water actually enters.

Several things are left to the site visit and cannot be settled from a desk. The technician needs to measure the exposed wall area and any crack lengths, because pricing for basement work is set per square metre and crack injection is set per metre. The condition of the existing wall surface, whether it is sound, damp, salt-stained, or flaking, decides whether a spray foam, epoxy coating, or a membrane will bond properly. The presence of a bathroom or a water tank within the basement also changes the scope, and those areas are priced separately. Ceiling height, access for equipment, and whether the adjoining neighbour's wall is shared should all be noted on the day rather than guessed at beforehand.

For the technician, a short working sequence helps. Record the basement area and wall height, mark every crack and note its length, and photograph the walls and floor edge before any preparation starts. Note whether the duplex has an upper unit above the basement that may need protection from splashes during works. Confirm which finish the homeowner expects, whether a full basement coating, a bathroom coating, a roof treatment, or a tank lining, since each sits in a different price band and needs its own preparation. Leave a written record of the measurements so the quote and the finished work can be matched against the same figures.

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

Signs that call for 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 — we check this before anything else.
• A common cause: a high groundwater level.
• Cracks at construction joints — we check this before anything else.

How we choose the tool in Aldarb

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 — Aldarb

Short answers for Aldarb

Common mistakes we see

• Painting the basement wall while the water comes from outside

What you get after the work

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