Bitumen membrane for duplexes in Alqunfudhah

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

Bitumen membrane in Alqunfudhah: the local context

Alqunfudhah is about 0.4 km from the sea coast (OpenStreetMap). The centre of Alqunfudhah sits about 7 m above sea level (SRTM open elevation data).

Team note on Alqunfudhah: 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..

A typical owner of a duplex in Alqunfudhah notices the same thing again and again: the roof looks sound until the first heavy rain shows damp patches on the upper floor ceiling. The owner wants a durable, sensible fix for the flat roof without paying for coatings that the building does not need. Many owners in this situation are expats renting out one unit and living in the other, so the work has to be planned carefully and finished in a way that protects both households.

The local facts matter here. The centre of Alqunfudhah sits about 7 m above sea level, and the town is about 0.4 km from the sea coast. Those two details mean the property is close to the coast and low-lying, so moisture from the air and the ground can be a steady presence rather than an occasional problem. For a roof, a bitumen membrane is a strong option, and it typically costs SAR 15–35 per m². Owners should compare that figure with liquid roof waterproofing at SAR 8–25 per m², which can suit lighter exposure, and with XPS boards at SAR 12–30 per m² when extra insulation is also wanted. The right choice depends on the roof's condition and how the building is used.

A practical sequence keeps the job manageable. First, walk the roof after rain and mark every pooling area, crack and upturned edge, then ask a contractor to measure the roof area so you can price the work per m². Second, clear loose material, dust and old debris, and treat any cracks before anything else, since crack injection is priced per metre at SAR 40–120 per m. Third, lay the chosen membrane system and check that it runs up the parapet walls and into drainage outlets. Fourth, test the roof with a controlled water check before the upper unit is handed back to the tenant. Finally, record the date and the materials used, so future inspections have a clear reference.

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 bitumen membrane:

• Old rolls that are cracking
• A flat concrete roof that needs waterproofing

Where the problem usually comes from

• Seams that were not welded properly — we check this before anything else.
• No protection layer — we check this before anything else.

Tools and methods, and when we use them

The steps in order

1. Preparation: Cleaning, priming and repairs.
2. Torch welding: Overlaps are welded and checked.
3. Details: Upstands, drains and bases.
4. Protection and flood test: Protection is laid after a successful flood test.

Quick comparison: facts and costs in Alqunfudhah

Short answers for Alqunfudhah

Common mistakes we see

• Leaving the membrane exposed without protection

The written outputs

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