Waterproofing and Leak Sealing in Dubai

So the first visit is an investigation, not a repair. We establish what kind of water it is before deciding what to do with it. Clean, constant and unrelated to weather usually means a pressurised supply line or a water heater. Appearing only after someone showers points at a wet area above. Appearing in summer, in a ceiling under a bulkhead or near a fan coil unit, is very often condensate: a blocked or badly fallen drain line backing up, or uninsulated pipework sweating in a humid void. Appearing after rain, and only after rain, moves the search to the roof, the parapet, the terrace or a window seal.

The method follows the question. Moisture readings across a wall or ceiling map the wet zone and show which way it dries. Isolating the water supply and watching whether the leak continues separates plumbing from building fabric. A wet area can be flood tested: plug the drain, hold water on the floor, watch below. On a roof or terrace, sections are tested in turn rather than all at once, because a test that covers everything tells you nothing. Where we cannot see it, we open a small, agreed inspection point rather than guess, and nothing is cut without telling you first.

If the source turns out to be plumbing rather than the building envelope, we say so and quote the plumbing repair instead. Selling you a membrane that will not stop the leak is a bad trade for both of us.

There is an obvious conflict in that, and the honest way to handle it is to name it. The firm investigating your leak is also the firm that would like to sell you the membrane, so the investigation has to stand on its own. You get told what we found, how we found it, and what we ruled out, and if the answer is a plumber or a conversation with your owners' association rather than a waterproofing job, that is what the report says. A firm that finds a membrane job on every visit is not investigating anything. Our water leak detection page covers the investigation side in more detail.

Roof work usually covers some combination of these.

• Stripping or overlaying a failed membrane.
• Correcting falls with screed so water actually reaches the outlets.
• Re-detailing upstands where the roof meets a parapet or a plant room wall.
• Sealing around every penetration: condenser feet, AC pipework, vents, aerials and lightning conductors.
• Sealing parapet copings and joints.
• Replacing rainwater outlets and adding leaf and sand guards.
• Applying a reflective top coat where the roof is exposed.

Roofs carrying air-conditioning plant need different thinking. Condensers get serviced, so someone walks that roof regularly, and a bare membrane does not survive foot traffic; walkway protection along maintenance routes costs a fraction of a re-do. Plant condensate also runs onto the roof through summer, so part of the surface stays wet while the rest is bone dry, and that is where the membrane ages first.

We also do the boring part properly. The roof is cleared, swept and washed before anything is applied, because membranes fail at the bond line far more often than in the middle of the sheet, and the bond line is where the dust was.

Balconies fail at edges and details rather than in the middle of the tiled field. The usual culprits are the door threshold, where the finished level outside is too close to the level inside; the junction between the floor and the balustrade upstand or the wall; the drain outlet, where the membrane was never dressed into the pipe properly; and cracked grout that lets water into a bed that has nowhere to drain. Grout is not waterproofing. A tiled balcony holds water in the bed under the tiles unless there is a working membrane and a drainage path below the tile.

The fix depends on what we find. Sometimes it is localised: cut out and re-detail the threshold and the outlet, rake out and replace failed joints, seal the upstand junction. Where the membrane below the tiles has gone, or where there never was one, the tiles come up, the substrate is prepared and levelled to a correct fall, a liquid membrane is applied and dressed up the upstands and into the outlet, and the floor is retiled over it. That is the more expensive route and we will tell you plainly when the cheaper one is a gamble.

Terraces and roof gardens add planters, decking, pergola posts and sometimes a jacuzzi, each of which is a hole through the waterproofing or a permanently damp zone above it. Anything bolted through a terrace needs to be sealed as a detail in its own right, which is why we quote fixings and waterproofing together on outdoor projects rather than pretending they are separate trades. Where the pergola or shade structure is also ours, the post bases and the membrane are detailed as one job and there is nobody to blame later.

The symptom is rarely dramatic. Paint blistering on the far side of the shower wall. A skirting lifting in the corridor. A damp patch on the ceiling below that gets slowly bigger. Silicone that goes black a week after it is replaced, because the moisture is behind it rather than on it.

Wet-area work covers re-tanking a shower or a full bathroom floor, correcting falls so the floor drains to the waste instead of holding a puddle at the door, re-detailing around wastes and floor drains, sealing pipe penetrations, making good the damage on the other side of the wall, and replacing failed sealant with the joint cut back to sound material first. Where tiles have to come up, we agree that before we start, because it changes the scope, the mess and the time the bathroom is out of use.

Regrouting alone solves a cosmetic problem, not a leak. If the water is getting under the tiles it will keep going under them. Where regrouting genuinely is the answer, we say so, and our regrouting service covers it.

Negative-side work, meaning waterproofing applied to the inside face of a structure that is pushing water at you, needs a different product family from the positive-side membranes used on a roof. Cementitious crystalline and slurry systems are designed for it. Cracks that are actively weeping are usually injected with resin before any coating goes on, because a coating over a live leak simply lifts.

Planters and raised beds are quietly one of the most common causes of damp villa walls. A planter built against the house, filled with soil and irrigated daily for years, is a permanent water source held against the structure. Doing it properly means lining the inside, drainage at the base, and a route for that drainage that goes somewhere sensible rather than into the wall.

Tank interiors, lift pits, plant rooms and podium slabs over occupied space follow the same principle: the junction detail matters more than the coating in the middle. If a tank is being drained for waterproofing anyway, cleaning and disinfecting it at the same time makes sense, which is covered on our water tank cleaning page. Where the structure being sealed is a pool shell rather than a tank, that is pool construction and renovation work, and the membrane sits under the tile system rather than on top of it.

Ultraviolet exposure is the first killer. An exposed roof membrane takes a punishing UV dose for most of the year, and cheap coatings chalk, harden and craze long before their nominal life. Surface temperatures on a dark roof in July run far above air temperature, so the material is being cooked as well as irradiated.

Thermal movement is the second. The structure expands and contracts through a large daily temperature swing, and it does that at joints, at parapets, and where two different materials meet. A membrane that is rigid, or that has been carried straight over a movement joint, splits there first.

Salt-laden humidity, particularly along the coast and the man-made islands, corrodes fixings and poorly protected metal flashings. Rust streaks running down from a fixing usually mean the fixing has failed as a seal.

Dust works two ways. It blocks outlets so water sits where it should have drained, and it contaminates surfaces so new coatings do not bond.

Finally there is the rain itself. It is not frequent, but when a heavy event arrives it arrives all at once, and a roof that copes with an ordinary shower can be overwhelmed. This is why we do not treat waterproofing as a seasonal job to be booked in November. The failures build up quietly through the summer and the rain only reveals them.

On a new property, the details that will fail later are worth looking at while the developer is still liable for them: the balcony threshold level, the outlet, the upstand junction and the roof penetrations. That inspection is a handover inspection of the details rather than a waterproofing job, and it costs far less at handover than it does after the first wet season.

• Liquid-applied membranes, typically polyurethane or acrylic hybrids. No joints, good around awkward details, penetrations and upstands, and the usual choice for balconies, terraces and interrupted roofs.
• Cementitious systems. Bond to concrete and masonry and suit wet areas, tanks, planters and negative-side work.
• Sheet membranes, self-adhesive or torch applied. Suit large uninterrupted areas and below-grade work.
• Reflective top coats. Reduce surface temperature on exposed roofs.
• Injection resins. Deal with live cracks and construction joints.

Each family has different cure requirements, foot-traffic tolerance and rules about what can be laid over it.

What decides the choice is the substrate condition, whether the finished surface will be exposed or covered with tiles or pavers, whether it will be walked on, whether there is standing water, whether the water pressure is on the front or the back of the structure, and how much cure time the property can afford. A bathroom in an occupied apartment and a plant-room roof have completely different constraints.

We specify the system in the written quote, so you know what is going on your building rather than "waterproofing" as a single line.

In a villa you generally have straightforward access, a roof you can get plant and material onto, and a single decision maker. The work tends to be larger in area and can run continuously. Community rules still apply for contractor access, and communities with a master developer may require approval for anything that changes the external appearance.

In an apartment you share structure with other people. A balcony leak affects the unit below, and the unit below should be kept informed. Material and waste move through a service lift that has to be booked, which changes how the job is planned.

In a tower, roof and façade elements are usually common property rather than yours, so the right first step may be a conversation with the owners' association rather than a quote to you. We will tell you when that is the case instead of quoting for work that is not yours to commission.

Occupied properties get an extra layer: dust screening, floor protection on the route in, and staging the work so a family still has a functioning bathroom while another is out of service.

First, a site visit and investigation. We look at the damaged area, the likely sources above and behind it, the roof or balcony in question, and the drainage. Where the source is not obvious, we test rather than assume.

Second, a written quote. It states what is being sealed, what preparation is involved, which system is being applied, what is being removed and reinstated, and what is not included. If tiles have to come up, or a ceiling has to be opened, that is in the quote before you agree to it, not discovered halfway through.

Third, preparation, which is most of the job and the part that decides whether it lasts. Removal of failed material, cleaning back to a sound substrate, crack treatment, forming or correcting falls, priming.

Fourth, application, including the detail work at upstands, outlets and penetrations, in the number of coats the system requires and with the cure time it requires between them. Rushing cure is how a good product fails.

Fifth, testing where testing is possible: flooding a wet area or balcony and checking below before anything is tiled over.

Sixth, reinstatement: tiling, screed, skirting, painting and cleaning down, including stone floor restoration where marble or terrazzo has been lifted, marked or left with a dull patch by the work. Then we walk the job with you.

If that is the sequence you want run on your building, send photographs and we will tell you which stage yours starts at.

What moves the price:

• The area, and how much failed material has to come off.
• Level correction, where falls have to be rebuilt rather than patched.
• The number of details, upstands and penetrations, which is where the labour actually goes.
• The system specified, and the cure time it needs between coats.
• Access, including lift booking and permitted working hours.
• Reinstatement, meaning how much tiling, screed, plaster and paint follows the sealing.

Warranty terms for your job are confirmed in the written quotation. Both cover our workmanship on what we did. Neither covers a new failure somewhere we were not asked to work on, which is another reason the investigation stage matters.

To move it forward, get a written quote with photographs of the affected area.