Floor & balcony waterproofing for duplexes in Jubail

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

Before we start: what we know about Jubail

Team note on Jubail: 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 Jubail sits about 4 m above sea level (SRTM open elevation data).

Jubail is about 0.9 km from the sea coast (OpenStreetMap).

An owner of a duplex in Jubail often lives on one floor and rents or uses the other, and the upper floor's balcony and terrace can quietly become the source of leaks into the rooms below. Water may appear first as a faint stain on a ceiling, a soft patch near a balcony door, or cracks at the edge where the tiles meet the wall. Because the upper and lower units share a structure, one neglected balcony can affect the household beneath it, so the owner usually wants a fix that works for the whole building rather than a quick patch on one surface.

The local facts shape how that decision should be made. The centre of Jubail sits about 4 m above sea level, which means the land is low and flat, so surface water has little natural slope to drain away quickly after heavy rain. Jubail is also about 0.9 km from the sea coast, so salty, humid air is a constant presence, and it can wear down exposed finishes and speed up deterioration around joints and drains. For a duplex, these two facts together argue for choosing a waterproofing system with good adhesion and a durable surface, and for keeping drainage outlets clear so water is not left standing on the balcony floor.

A practical sequence starts with a walk-through of both floors, marking every crack, stain, and place where tiles sound hollow. Next, clear the balcony and terrace, check that drains and outlets are open, and repair any cracks, using crack injection where a line runs through the structure, which is typically priced per metre. Then choose the surface system: liquid roof waterproofing for open terraces and bitumen membrane where a heavier layer is needed, with epoxy coating or spray foam for surfaces that need a more resilient finish. Finally, test the finished area by running water across it and watching the ceiling below for several days before the work is signed off.

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

Signs worth paying attention to

These are the signs most often linked to floor & balcony waterproofing:

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

The most common causes

• A common cause: a blocked drain.
• A threshold without waterproofing.
• A common cause: incorrect falls.

Tools we use in Jubail

From the first visit to the report

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.

Facts and costs — Jubail

Short answers for Jubail

What we advise against

• Tiling a balcony without waterproofing

The written outputs

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