Fahison
Foam Thinner Than Required
High- Cause:
- Thin or uneven spraying.
- Impact:
- Poor thermal insulation and heat on the top floor.
Stage 3: Waterproofing WorksRoof Waterproofing
Roof Waterproofing
The Combo System
The combo system combines thermal insulation and waterproofing in layers on the roof: polyurethane foam, then a waterproofing membrane, then geotextile and a protective screed with joints, then a reflective top coat. We take handover and check thicknesses, falls, corners and outlets, and carry out a roof flood test.
From 700 AED
1Single Handover Inspection
- Specialised Engineers
- Photo Report
- All Emirates
Combo System LayersIllustration
Thermal insulation (foam)Waterproofing
What Is Roof Waterproofing?
The combo system is the most widely used roof waterproofing system in the UAE, combining thermal insulation and waterproofing: polyurethane foam is sprayed onto the roof and covered with a waterproofing membrane, then a geotextile layer, then a protective screed divided by joints, and finally a heat-reflective top coat.
The roof waterproofing inspection is an engineering visit in which our engineers check the thickness of each layer, the falls, and the detailing at the parapet, outlets and pipes. It matters because roof leaks show up on the top floor ceilings and damage gypsum and paint, while weak thermal insulation raises room temperatures and the electricity bill.
Handover of Roof Waterproofing
We inspect the combo system layers and verify thicknesses and details.
Single Inspection
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Roof Waterproofing Handover
When: During application of the combo system layers and before they are covered, in coordination with the waterproofing contractor.
Each layer of the combo system is covered by the next. We check thicknesses and details at the right time, because correcting them after the screed means breaking out.
Key Items We Inspect
Surface Preparation
Roof clean and dry, with protrusions treated before spraying.
Foam Thickness
Measuring polyurethane foam thickness with a thickness gauge.
Falls
Falls directed towards the rainwater outlets.
Membrane
Full coverage of the foam, and its thickness.
Flood Test (Roof Flooding)
Flooding the roof with water after the waterproofing membrane and checking for leaks.
Parapet Upstand
Height of the waterproofing up the parapet wall, and its fixing.
Outlets and Pipes
Detailing around rainwater outlets and AC pipes.
Geotextile
Coverage and laps before the screed.
Screed and Joints
Screed thickness and division with joints.
Top Coat
Reflective top coat covering the entire roof.
Most Common Problems at This Stage
Reverse Falls
High- Cause:
- Falls not set.
- Impact:
- Water ponding on the roof and leaking over time.
Leaks Around Outlets and Pipes
High- Cause:
- Incomplete detailing at openings.
- Impact:
- Stains on the top floor ceiling.
Equipment We Use
From the Fahison equipment featured on our home page.
Thickness Gauge
Tips Before the Inspection
To help you get more out of the visit.
Do
- Make sure the AC contractor finishes their pipework before waterproofing.
- Request the inspection before the protective screed so we can see the foam and waterproofing.
- Ask the contractor for the system data sheet and the required thicknesses.
Avoid
- Covering the waterproofing before it is inspected.
- Installing AC unit bases on top of the waterproofing without proper treatment.
- Walking on the foam or waterproofing before it is protected.
Frequently Asked Questions
Common questions about Roof Waterproofing.
What is the combo system?
A roof waterproofing and insulation system that combines thermal insulation (polyurethane foam) and waterproofing, with geotextile, a protective screed and a heat-reflective top layer.
Why does the foam thickness matter?
Because the foam is the thermal insulation. The thinner it is than required, the hotter the top floor and the higher the AC bill.
How much does a roof waterproofing inspection cost?
From 700 AED.
Inspections in the Same Stage
Waterproofing & Insulation.
Has Your Roof Waterproofing Started?
Book the inspection before the protective screed, and we'll arrange a visit time with you.