Floor & balcony waterproofing for duplexes in Qatif

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

Before we start: what we know about Qatif

Qatif is about 2.5 km from the sea coast (OpenStreetMap). The centre of Qatif sits about 5 m above sea level (SRTM open elevation data).

Team note on Qatif: 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..

Before any material is chosen for a duplex floor or balcony in Qatif, the first thing to check is how close the building sits to salt air and low ground. The centre of Qatif sits about 5 m above sea level, and the town is about 2.5 km from the sea coast. Those two facts mean salts can settle on surfaces and moisture can linger in the slab, so the technician looks first at the condition of the existing membrane, the edges where the floor meets the wall, and any sign of salt bloom or efflorescence on the underside of the balcony. Where the floor drains into a shared stack, the slope and outlet points are also checked early, because standing water is what usually shortens the life of a balcony finish.

Several things can only be judged on site and are left to the visit. The technician needs to see the actual substrate, whether it is sound concrete, screed or old tiles, and whether it has been sealed before. Crack width and movement decide whether crack injection is needed, and that is priced per metre, so the length must be measured in person. The choice between liquid roof waterproofing, bitumen membrane, spray foam or epoxy coating depends on exposure, foot traffic and whether the balcony is open or covered. For a duplex, the technician also confirms access between the two units, the timing that suits both households, and whether the floor below has a finish that could be affected during work. Prices for each option are quoted as ranges per square metre or per metre, so the final figure follows the measured area rather than a fixed rate.

To help the technician arrive prepared, residents should share any previous repair records, the year the balcony or floor was last treated, and photographs of cracks, stains or blistering taken in daylight. It helps to note where water appears after rain or after washing, and whether the problem sits near a wall, a drain or the balcony edge. Clear access to the roof or the unit above, and a rough sketch of the floor plan with dimensions, speeds up the survey. With these details in hand, the technician can compare the options, such as XPS boards for insulation under a finish or epoxy for a sealed surface, and recommend the one that fits the building.

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

Signs worth paying attention to

If you notice one of these signs in Qatif, it is a good moment to talk to the team:

• A wrong fall towards the door threshold
• Water passing from the balcony to the floor below
• Damp under the light well

Where the problem usually comes from

• Incorrect falls — we check this before anything else.
• A threshold without waterproofing.
• A common cause: a blocked drain.

How we choose the tool in Qatif

How the work is done, step by step

1. Checking the falls: Where water collects and where it should go.
2. Details: Thresholds, drains and upstands.
3. Waterproofing: The layer is applied and protected.
4. Flood test: Tested before the finish goes on.

Qatif in facts and sources

Questions from Qatif

Common mistakes we see

• Tiling a balcony without waterproofing

What you receive

You receive: the flood result and photos of the details, in a technical report with a verification code.