Roof waterproofing FAQ

Less than most companies claim, but it's real. Published UAE villa studies show roughly 0 to 7 % lower annual electricity from the roof alone. Your result depends on how well the roof is already insulated and how reflective it is today. For a typical 200 m² villa roof, our estimate is about AED 150 to 1,000 a year on an insulated combo roof, and up to about AED 2,000 a year on a poorly insulated or dark roof. These figures use today's DEWA tariff and are estimates, not a guarantee. We show the full calculation in our cool roof guide.

SRI (Solar Reflectance Index) rates how cool a surface stays in the sun: a standard black surface is 0, a standard white is 100. Henkel Polybit's datasheet for white Polythane P states an SRI above 80 (ASTM E1980) and solar reflectance above 75 % (EN 410). For comparison, Dubai's green building code (Al Sa'fat 304.01) asks for an initial SRI of at least 78 on new flat roofs.

Every white roof gets dusty, and dust lowers reflectance. UAE field studies measured large SRI drops within three years on uncleaned surfaces. Polythane P is UV-stable and needs no separate topcoat, but to keep the cooling effect we recommend rinsing the roof and clearing the drains at least once a year, ideally before the rainy season. Your yearly check includes this advice.

No. Insulation (like the PU foam inside most combo roofs) slows heat flowing through the roof. A cool roof stops much of the heat from being absorbed in the first place. They work together. On an already-insulated roof, the cool finish adds a smaller energy saving but still lowers surface temperature and thermal stress on the roof build-up.

Most Dubai villa leaks start at details, not in the open roof: cracked screed joints, failed sealant, drains, AC plinths, pipe and cable penetrations, and parapet upstands. In a typical combo roof the actual waterproofing layer is buried under the screed, so water can travel along it and appear on a ceiling metres away from where it entered. That's why we inspect with a thermal imaging camera and moisture readings rather than guess.

Treat it as urgent. Water in a slab can reach electrical conduits, spoil gypsum ceilings and cause mould. Switch off power to affected light points, collect the water, photograph the stain and send us photos on WhatsApp. We'll advise on a temporary measure and book a free roof inspection.

Water held in the screed and insulation layers keeps draining through cracks for hours or even days after rain. A ceiling that drips after the sky is clear usually means water is trapped above it. That has to dry out or be drained before any membrane goes on.

No, and nobody should. The substrate must be dry and clean before priming and coating. We schedule around the forecast and won't coat a damp roof, because trapped moisture causes blistering and poor adhesion.

No. A roof membrane protects the roof. Some 'roof leaks' actually come through parapet cladding, precast seams or window frames. Our inspection checks these too and tells you honestly if the roof isn't the culprit.

Henkel Polybit Polythane P: a single-component, hybrid polyurethane liquid membrane that is UV-stable and needs no topcoat. On absorbent concrete we prime first. Corners, drains and penetrations are reinforced with reinforcing fleece, movement joints are sealed with Polyseal 1PU and backer rod, and damaged screed is repaired with Polycrete repair mortar before coating. The membrane goes on in three coats, about 2.4 L/m², which the datasheet rates at about 1.5 mm dry film thickness.

No. 'Hybrid' describes the chemistry, not the quality. Several well-known European systems are hybrids too; Frankosil 1K Plus, for example, is described as a polyurethane hybrid in its European Technical Assessment. What keeps water out is the measured thickness, reinforced details and a proper build-up. That's why we measure dry film thickness on every roof and flood-test it before you pay the final instalment.

For an exposed overlay on an existing villa roof, a liquid membrane has clear advantages: no torch, no seams, it follows every detail and stays elastic (datasheet: elongation above 500 %, crack bridging 1.5 mm). Torch-on bitumen is a proven system but usually needs protection from UV and heat, and its seams and laps are the weak points. Our guide compares PU, bitumen and cementitious systems in detail.

Usually not. We clean the roof, open and reseal failed joints, repair loose or hollow screed, prime and then coat over the sound surface. If the inspection finds a failed, debonded coating, we remove that layer first. You'll see this in the quote before work starts.

The datasheet reports no leakage at 5 bar hydrostatic pressure. Even so, ponding water collects dust and shortens the life of any roof. Where water ponds, we correct falls around drains with repair mortar as part of the quoted repairs.

A technician comes on site and checks the roof with a thermal imaging camera and moisture readings. They inspect drains, joints, plinths, penetrations and parapets, and measure the area. You get a photo report and a fixed quote. Nothing is charged and there's no obligation.

For a typical villa roof, about one week on site, depending on repairs and weather. Each coat needs at least 6 hours before the next, and the membrane reaches full strength after 7 days. The 48-hour flood test follows the coating.

Yes. All work happens on the roof, and the membrane is water-based with low VOC (under 20 g/L per datasheet). We coordinate access, AC units and solar panels with you in advance.

Any dry period. Book before the rainy months: rain in the UAE mostly falls between November and April, and contractors fill up fast after the first storm. In summer we work early in the day, because the membrane must be applied below 45 °C (ambient and material temperature, per datasheet) and outdoor work is banned 12:30 to 15:00 from 15 June to 15 September.

We measure dry film thickness on every roof and record it. Where the roof can be dammed, we flood-test it for 48 hours. Then you receive a serial-numbered 10-year written warranty by Sorento: a contractor warranty with a QR code that links to the record of your roof. This is not a separate Henkel manufacturer warranty.

The Sorento Roof System starts from AED 249/m² excluding VAT, with a fixed written quote after a free inspection. The minimum job is AED 3,000 for spot repairs; a full roof starts at 60 m². A typical 200 m² villa therefore comes to about AED 47,500 to 57,500 excl. VAT as an indicative range. Use our online estimator for a low and high band in three short steps.

Low quotes usually mean fewer or thinner coats, no reinforcement at details, little repair work, and no thickness measurement or flood test. Compare quotes line by line: number of coats and litres per m², measured thickness, how drains, joints and plinths are detailed, what repairs are included, and what the warranty actually covers.

Watertightness of the roof areas and details we waterproofed, for 10 years from completion. It is a **10-year written warranty by Sorento**, issued by the licensed contractor who did the work, not by Henkel. You get a serial-numbered certificate with a QR code that you, or a future buyer, can scan to verify the roof, date and test records. The certificate states the exact terms and exclusions, such as damage caused later by others drilling through the membrane.

Sorento gives a **10-year written warranty** on the waterproofing. How long a roof actually lasts beyond that depends on thickness, details, ponding and maintenance. A yearly rinse, clear drains, and no unsealed new penetrations (AC, solar, satellite) make the biggest difference. The Sorento Roof System includes a check-up after 12 months.

It depends on your community and the scope. Emaar, for example, says regular maintenance needs no NOC, but alterations do, and contractors always need an entry permit. In Tilal Al Ghaf, approvals run through Majid Al Futtaim (Belong by MAF), plus the Dubai Development Authority where required. We check the requirement for your villa and handle the paperwork, including MAF NOC and DDA approval in Tilal Al Ghaf.

Villa communities across Dubai, including Tilal Al Ghaf, Arabian Ranches, Dubai Hills Estate, Emirates Hills, Jumeirah and Palm Jumeirah. If your community isn't listed, ask us. Most master communities follow a similar approval route.

Possibly. Developers typically give a defects liability period after handover, and UAE civil law sets a 10-year liability for serious structural defects (now Article 821 of the Civil Transactions Law, formerly Article 880). Whether a roof leak qualifies depends on the case. Report it to your developer in writing first and keep photos. If it's no longer covered, we're happy to inspect. This is general information, not legal advice.

Sorento is a **licensed contractor** for renovation, construction and waterproofing works. Sorento Roofsealing projects are executed, invoiced and warranted by Sorento Real Estate L.L.C., Dubai Hills Business Park, Dubai. You sign one contract with one company that is responsible for the inspection, the work and the **10-year written warranty by Sorento**. We do not claim a separate Henkel manufacturer warranty. ---