Roof waterproofing for duplexes in Alaridah
In short: In Alaridah (Alaridah), roof waterproofing for duplexes begins with the roof, falls and drains survey and the moisture meter for ceilings and walls; nothing is opened until the position is clear. The centre of Alaridah sits about 2591 m above sea level (SRTM open elevation data). Pricing starts from Liquid roof waterproofing (per m²) (SAR 8–25 per m²), and other items are quoted after the visit.
Before we start: what we know about Alaridah
The centre of Alaridah sits about 2591 m above sea level (SRTM open elevation data).
The centre of Alaridah sits about 2591 m above sea level (SRTM open elevation data), which places the neighbourhood on a high plateau where roofs take a steady load of sun, wind and sudden rain. At this height, daytime heat can be strong while nights turn cool, so roof surfaces expand and contract every day. For duplex owners, this means the roof is often the part of the building that works hardest, and waterproofing is not a one-time job but a protective layer that has to cope with constant movement.
Because of that climate, the roof work we plan for Alaridah duplexes starts with the surface and the joints. Liquid roof waterproofing is priced at SAR 8–25 per m², and it suits flat roofs where a seamless film can follow the shape of parapets and drains. Bitumen membrane, at SAR 15–35 per m², offers a heavier layer for roofs that see more foot traffic or heavier water pooling. Where insulation is needed to reduce heat transfer into the upper floor, XPS boards at SAR 12–30 per m² can be fitted beneath a protective finish. Crack injection, at SAR 40–120 per metre, is used to seal small splits before any coating goes on, because a coating laid over an open crack will simply fail where the movement is greatest. Each of these options is chosen after the roof is inspected, not from a fixed package.
Owners in Alaridah often make the same few mistakes, and most of them are avoidable. The first is coating over a damp or dusty surface, which stops the layer from bonding. The second is ignoring the edges, the drains and the points where pipes or railings pass through the roof, since water finds these gaps first. The third is treating the roof as finished once the coating dries, when the sealant at joints still needs time to cure and should be checked after the first heavy rain. A fourth mistake is leaving water tanks on the roof uncoated or unchecked, because leaks from tanks can damage the top floor without warning. Planning the work around these points keeps the duplex dry and the repair costs low over the years.
In a duplex, the two floors often share lines, so tests are done floor by floor.
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
The most common causes
- Damaged waterproofing around tank and AC bases — we check this before anything else.
- Wrong falls towards the drains.
- Cracks in the roof slab — we check this before anything else.
Tools and methods, and when we use them
| Tool | What it finds | When we use it in Alaridah |
|---|---|---|
| Flood test | Whether the waterproofing holds before it is covered | Limits: for roofs with drains and wet areas before tiling |
| Roof, falls and drains survey | Ponding areas and the condition of the old layer | Limits: shows the condition, not the material alone |
| Moisture meter for ceilings and walls | Where water is entering now, from inside | Limits: measures the effect, not the water path |
The steps in order
- Survey: Falls, drains and the condition of the old layer are recorded.
- Preparation: Cleaning and repairs before any new layer.
- Primer: The base coat that the system needs.
- Waterproofing layers and details: Corners, upstands and bases get their own detail.
- Flood test: The roof is flooded and checked before it is covered.
Alaridah in facts and sources
| Item | Value | Source |
|---|---|---|
| District profile | The centre of Alaridah sits about 2591 m above sea level (SRTM open elevation data) | SRTM (NASA) open data |
| Liquid roof waterproofing (per m²) | SAR 8–25 per m² | Owner price list (Alaridah) |
| Bitumen membrane (per m²) | SAR 15–35 per m² | Owner price list (Alaridah) |
Short answers for Alaridah
What is the first step of roof waterproofing for duplexes?
We start with survey (falls, drains and the condition of the old layer are recorded), then preparation (cleaning and repairs before any new layer).
How much does roof waterproofing cost in Alaridah?
From our published price list: Liquid roof waterproofing (per m²) SAR 8–25 per m²; Bitumen membrane (per m²) SAR 15–35 per m². Quantities are confirmed at the inspection.
What do I get at the end?
A quality record with photos and the flood-test result, in a technical report that carries a verification code.
Mistakes that cost more
- Covering the waterproofing before the flood test
- Ignoring the tank bases
The written outputs
You receive: a quality record with photos and the flood-test result, in a technical report with a verification code.
Planning the visit in Alaridah
- Have access ready to the water meter, the tank hatches, the roof and the main valve; in apartment buildings the roof keys are often with the building guard (haris).
- Prices are in Saudi riyals (SAR); the final price is confirmed after the inspection, before any work starts.
- Keep photos of the problem and of any earlier repairs — they help the technician compare before and after.
- If you rent, tell your landlord or building management before the visit and agree in writing who pays; the written report can be shared with them.
Sources and method
- SRTM (NASA) open data
- Owner price list for Alaridah
- Local pages are published only after a quality gate: real local facts, text similarity of no more than 15% with any other English page, and a claims check.
- النسخة العربية