Bitumen membrane for villas in Alzulfi

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

Before we start: what we know about Alzulfi

Main roads in or near Alzulfi: King Fahd Road, Sheikh Ibn Baz Square, King Salman Road. The centre of Alzulfi sits about 615 m above sea level (SRTM open elevation data).

Team note on Alzulfi: 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..

Bitumen membrane on villa roofs in Alzulfi most often fails through ponding and blistering, where water sits on flat sections, works under the membrane and lifts it over time. Villa roofs are often large, flat and crossed by parapets, pipes and rooftop tanks, and each of these joins is a place where a poor seal lets water in. Leaks then show up on ceilings and upper walls, sometimes long after the original work was done, which is why a roof that looked sound at handover can start to fail within a few seasons.

Alzulfi's setting changes how this should be approached. The centre of Alzulfi sits about 615 m above sea level (SRTM open elevation data), which places it on the high ground of the Hijaz mountains rather than on the coastal plain. Rain here tends to arrive in short, heavy bursts that run off quickly across sloping surfaces, so drainage outlets, slopes and upstands need as much attention as the membrane itself. Bitumen membrane is priced at SAR 15–35 per m², and that figure only holds up if the falls to outlets are correct and the upstands are properly lapped. In practice, a good scope for a villa in Alzulfi will look at drainage before it looks at the surface, and will say so clearly in the quote.

Before the visit, it helps to have a few things ready. Note the roof area in square metres, the number of outlets, and whether there is a rooftop water tank, since tank internal coating is priced separately at SAR 25–60 per m². Mention any past leaks, where they appeared and when, and whether an old membrane is still in place or has already been removed. If the roof has cracks in the parapet or walls, ask whether crack injection (SAR 40–120 per metre) is included in the assessment. Finally, ask the provider to walk the roof with you, point out the low spots and explain the proposed drainage fixes before any figure is agreed.

In a villa, tanks, the roof and the yard lines are usually yours to look after, so it helps to know where the main valve and tank hatches are.

Signs worth paying attention to

The following signs are worth checking before they grow:

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

Causes we see in the field

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

Tools and methods, and when we use them

How the work is done, step by step

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.

Alzulfi in facts and sources

Questions from Alzulfi

Mistakes that cost more

• 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.