Bathroom waterproofing for duplexes in Alkharj

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

Why bathroom waterproofing differs in Alkharj

Main roads in or near Alkharj: King Abdullah Road. The centre of Alkharj sits about 439 m above sea level (SRTM open elevation data).

Team note on Alkharj: 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..

The centre of Alkharj sits about 439 m above sea level, and that elevation is the first thing we look at when a duplex bathroom shows signs of moisture. Because the ground here is not flat and drainage can vary from one plot to the next, we check how water is likely to move toward the walls and floor before we touch any tiles. We also note whether the bathroom sits above a shared space or an upper unit, since water that gets through one floor can travel quietly into the neighbour's ceiling. Pricing for this work usually falls in the range of SAR 15–40 per m² for bathroom waterproofing, so the first visit is about confirming the true area and the scope rather than guessing a total from the photos.

Several things can only be judged on site. The technician needs to see the condition of the existing tiles, whether grout lines are cracked, and whether the old membrane has lifted at the corners. Crack injection, priced at SAR 40–120 per metre, is only recommended once the crack has been traced and its length measured by hand. The choice between 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 depends on the substrate, the slope to the floor drain and how much access there is to the wall edges. Where a water tank sits in the same plot, a tank internal coating at SAR 25–60 per m² may be discussed, but only after the tank walls are inspected. Likewise, if the flat roof above the bathroom is involved, liquid roof waterproofing at SAR 8–25 per m² or XPS boards at SAR 12–30 per m² are considered only once the roof surface has been looked at directly.

To help the technician arrive prepared, the resident should note when the damp first appeared, whether it worsens after rain or after heavy water use, and where the stain is largest. Clear photos of the wall and ceiling from both the bathroom and the room below are useful, along with the approximate size of the bathroom in square metres. Please also say whether anyone has tried a repair before and what material was used, as this affects how the old surface is prepared. Access to the water shut-off, the floor drain and the roof hatch should be arranged in advance so the visit can focus on assessment rather than setup.

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

Signs that call for bathroom waterproofing

These are the signs most often linked to bathroom waterproofing:

• Damp around the shower
• A stain under the bathroom on the floor below
• Worn grout

Causes we see in the field

• A damaged floor layer — we check this before anything else.
• Corners without waterproofing tape.
• A common cause: the area around the floor drain.

Tools and methods, and when we use them

The steps in order

1. Finding the source: A supply-pipe leak is ruled out first.
2. Preparation: The floor is opened and cleaned where needed.
3. Corners and details: Tape and detailing at corners, drains and pipe entries.
4. Flood test: The floor is tested before tiling.

Quick comparison: facts and costs in Alkharj

Short answers for Alkharj

Mistakes that cost more

• Waterproofing the floor while the supply pipe still leaks

The written outputs

The written output: the flood-test result and photos of each stage. The report is numbered and can be checked with its verification code.