Roof waterproofing for apartments in Al Mhmdya, Riyadh

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

Before we start: what we know about Al Mhmdya

The centre of Al Mhmdya is at 24.7326, 46.6503, about 3.3 km from the centre of Riyadh, with an approximate radius of 2 km. The approximate area shown on the map is centred here. Main roads in or near Al Mhmdya: King Fahd Road, King Abdullah Road, Al Takhassusi Road.

The centre of Al Mhmdya sits about 625 m above sea level (SRTM open elevation data). The nearest wadi channel is about 1.9 km from the centre of Al Mhmdya (OpenStreetMap).

The roof of an apartment building in Al Mhmdya, Riyadh, starts with its location. The centre of Al Mhmdya is at 24.7326, 46.6503, about 3.3 km from the centre of Riyadh, with an approximate radius of 2 km. The centre sits about 625 m above sea level, according to SRTM open elevation data. The nearest wadi channel is about 1.9 km from the centre, which means that when rain falls heavily, water can run off quickly across hard ground and gather where the roof drains are least able to cope. Because of this, the first things a technician looks at on a roof here are the drainage outlets, the upstands around the edge, and whether any ponding has already left marks or staining on the parapet walls.

Some points cannot be settled from a description alone and are left to the site visit. The technician will walk the roof to find cracks, blistering, lifted seams and areas where old waterproofing has failed. They will check whether the existing layer is a bitumen membrane, a liquid coating or boards laid over the slab, since this decides which repair is realistic. They will also look at the junctions with rooftop tanks, plant bases and stair enclosures, and note how far the water sits from the nearest outlet. Costs are only indicative until this is done. For reference, liquid roof waterproofing is SAR 10–25 per m², bitumen membrane is SAR 15–35 per m², spray foam is SAR 20–45 per m², and XPS boards are SAR 15–30 per m², but the final figure depends on the area and condition found on the day.

To help the technician, the resident or property manager should have the building's age, the number of floors, and any previous roof repair records ready. It is useful to note where water has entered previous ceilings, and to say whether any rooftop tank is in use, since tank internal coating is priced separately at SAR 25–65 per m². Photos taken after a rainfall, showing where water collected, are very helpful. Access arrangements for the roof and any stairwell keys should be confirmed in advance so the visit can cover the full roof in one trip.

In an apartment, a problem may start in your unit or in a shared line; we separate the two before any work.

Signs worth paying attention to

These are the signs most often linked to roof waterproofing:

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

The most common causes

• Cracks in the roof slab — we check this before anything else.
• A common cause: damaged waterproofing around tank and AC bases.
• A common cause: wrong falls towards the drains.

Tools and methods, and when we use them

From the first visit to the report

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.

Al Mhmdya in facts and sources

Questions from Al Mhmdya

Mistakes that cost more

• 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.