Short answer
Most basement car-park leaks in Abu Dhabi can be repaired without closing the car park. Injection is done from inside the structure, so only a few bays around the work zone are closed at a time, and the zone moves as each section is finished. A water-reactive foam stops active flow, then a flexible resin seals the crack permanently. Leaks coming down from an exposed deck above also need the deck surface treated, and moving expansion joints need a joint-sealing system.
In a residential tower, an office building or a mall, the basement car park is usually where leaks show first: water dripping from the soffit onto cars, wet bands along construction joints, puddles at the foot of the ramps. Closing a whole level for repairs is rarely acceptable to residents or tenants. With injection from inside the structure, it is rarely necessary.
Where do car parks leak?
- Construction joints. The joints between concrete pours in walls and slabs are the most common leak line, especially on the lowest levels, below the water table.
- Slab and wall cracks. Shrinkage and movement cracks, and cracks opened by corroding reinforcement where salty groundwater has reached the steel.
- Penetrations and pits. Pipe and drain sleeves, sump pits and lift pits.
- Ramps. The ramp slab and the joints where it meets the floor slabs.
- Soffits under podiums and upper decks. Rain and irrigation water from a landscaped podium or an open top deck travels down through cracks and drips onto the level below.
The source decides the repair. Groundwater coming in through the lower levels is sealed by injection from inside. Water coming down from an exposed deck or a landscaped podium also needs work on top, on the deck surface or its membrane, because every rain reloads the crack from above. Moving expansion joints are a separate case: they are designed to open and close, and usually need a flexible joint-sealing system rather than injection alone.
How is the work phased so the car park stays open?
- Survey and leak register. Every leak point on each level is photographed, numbered and marked on the car-park layout, with a note of whether it is active, damp or a dry stain. The register becomes both the work plan and the record.
- Small work zones. The work is split into zones of a few bays. Only the bays under and beside the zone being drilled and injected are closed with barriers and signs. The rest of the level stays in use.
- Protecting cars and finishes. Overhead injection can drip resin, so the bays under the work are emptied, not just covered. Floors, walls and equipment near the work are protected.
- Noisy work in agreed hours. Drilling is the noisy part, and it is scheduled in the hours set by the building management. The injection itself is quiet.
- Moving the zone. Once a zone is injected and checked, the barriers move to the next one and the finished bays reopen.
Ramps and entry and exit lanes are planned with the building management, typically in low-traffic hours or one lane at a time, so that access to the car park is kept.
What does the injection do?
The method is the same two-stage injection used in basements. Holes are drilled at an angle so they cross the crack inside the concrete, and packers are fixed in them. Where water is flowing, a water-reactive polyurethane foam goes in first and stops the flow. A flexible polyurethane resin then goes through the same packers and seals the crack permanently, and it can stretch with the small movements of a car-park slab. The full sequence is in basement leak repair in Abu Dhabi.
The most common reason a car-park repair fails is that only the drip was treated. Water follows a crack or joint for metres inside the concrete, so the whole length is injected, not just the point where it shows.
What should the facilities manager receive?
- A method statement and risk assessment for approval before work starts, including the zone plan and working hours. See what consultants check in a method statement.
- Technical and safety data sheets for every product.
- Progress by zone, listing the leak numbers closed.
- A completion report with before-and-after photographs for each leak number.
A re-check after the next heavy rain is worth scheduling. Any new leak is logged against the same register, so the building builds up a history instead of starting from scratch every season. That is the basis of a planned maintenance agreement.
What drives the cost?
A car park is priced from the leak register after the survey, not per square metre of floor. The main drivers are the total length of cracks and joints to inject, the number of active leaks, how much of the work is overhead, the permitted working hours, and how many zones the work is split into. Indicative basement ranges are in our waterproofing cost guide.
For how we work with facility managers and building owners, see leak repair for managed buildings.
Dot Expert is a X-Calibur Construction Chemistry registered applicator — our engineer and injection technicians have completed the manufacturer's site application training. View the certificate