Roof waterproofing for duplexes in Unaizah

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

What is specific about Unaizah for roof waterproofing

The centre of Unaizah sits about 667 m above sea level (SRTM open elevation data). Team note on Unaizah: 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 Unaizah sits about 667 m above sea level, a height that shapes how rain and heat act on a duplex roof. Sites at this elevation are open to strong daytime sun and sharp temperature swings, so the roof surface expands and contracts through the day. For a homeowner, this means the waterproofing system has to tolerate movement rather than sit rigidly on the slab. Crews usually check the roof for hairline cracks first, because small splits open up quickly under repeated heating.

Because of that movement, the choice of system matters. Liquid roof waterproofing is priced at SAR 10–25 per m², and bitumen membrane at SAR 15–35 per m², and both are common on Unaizah roofs. Liquid coatings suit irregular surfaces and parapets, while a membrane gives a thicker layer over flatter areas. Where insulation is wanted as well, XPS boards at SAR 10–30 per m² can sit above the waterproof layer. Crack injection, at SAR 40–115 per metre, is often needed before any of these are applied, so the cost of repairing the base is worth budgeting alongside the coating itself.

Owners on duplex roofs commonly make a few avoidable mistakes. Many skip the crack survey and paint over a failing surface, which only hides the leak for a season. Others compare quotes without checking whether the price covers surface preparation, since a coating laid on dust or loose screed will peel. Some also let water pool at drain outlets and edges, where the membrane is most likely to fail. Asking the crew to show the roof's crack map and the prepared surface before work starts helps prevent these problems.

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

Signs that call for roof waterproofing

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

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

Where the problem usually comes from

• A common cause: cracks in the roof slab.
• Damaged waterproofing around tank and AC bases.
• A common cause: wrong falls towards the drains.

Tools we use in Unaizah

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.

Quick comparison: facts and costs in Unaizah

Questions from Unaizah

Common mistakes we see

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

What you receive

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.