Roof waterproofing in Aljumum: for companies (annual contract)

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

Why roof waterproofing differs in Aljumum

The centre of Aljumum sits about 200 m above sea level (SRTM open elevation data). Team note on Aljumum: 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..

Roof leaks in commercial buildings usually start small: a hairline crack around a parapet, a blistered joint where the membrane meets a drain, or ponding water that sits on a flat roof after rain and slowly works into the slab below. For companies on an annual contract, the real cost is rarely the repair itself. It is the stock damaged, the ceilings stained, and the staff disrupted while the leak is found. Regular inspection and early treatment keep those problems from growing.

In Aljumum, the centre sits about 200 m above sea level, so the approach begins with the local setting rather than a generic roof system. Rain arrives in the same way across the city, but the roof surfaces take the same exposure and the same drainage questions, so the work focuses on outlets, upstands and any stretch where water is held rather than shed. For a roof that is coated rather than membraned, liquid roof waterproofing is usually priced at SAR 8–25 per m², while bitumen membrane sits at SAR 15–35 per m², and a contract should state clearly which system is being maintained and why. Where a roof also carries a tank or a basement beneath it, the same contract can cover tank internal coating at SAR 25–60 per m² and basement waterproofing at SAR 50–150 per m², so one annual schedule covers the whole building.

Before the first visit, ask the contractor to confirm the roof area in m², the current membrane or coating type, the position of every drain and outlet, and any known leak history with its location. Ask how crack injection is billed, since it is priced per metre at SAR 40–120 per m, and whether a repeat visit within the contract year is included. Request a written scope listing what is inspected each visit, what is repaired within the contract, and what would be quoted separately. A clear scope at the start is the simplest way to keep an annual contract predictable for the whole year.

For companies, an annual contract sets the scope, the visit schedule and the reports in writing.

Signs that call for roof waterproofing

The following signs are worth checking before they grow:

• Stains on the top-floor ceiling after rain
• Water pooling on the roof
• The old waterproofing is cracking

Causes we see in the field

• Damaged waterproofing around tank and AC bases — we check this before anything else.
• Wrong falls towards the drains — we check this before anything else.
• Cracks in the roof slab — we check this before anything else.

How we choose the tool in Aljumum

How the work is done, step by step

1. Survey: Falls, drains and the condition of the old layer are recorded.
2. Preparation: Cleaning and repairs before any new layer.
3. Primer: The base coat that the system needs.
4. Waterproofing layers and details: Corners, upstands and bases get their own detail.
5. Flood test: The roof is flooded and checked before it is covered.

Aljumum in facts and sources

Short answers for Aljumum

Mistakes that cost more

• Covering the waterproofing before the flood test
• Ignoring the tank bases

The written outputs

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