Method 03
Concrete wall core cutting in Abu Dhabi, Dubai & Al Ain
Horizontal coring through concrete, block and stone walls for air conditioning, extract, drainage and service penetrations. Drilled to a fall, sealed and made good on both faces.
What it is
When to specify wall core cutting
Wall coring is horizontal core drilling, and the differences from slab work are practical rather than structural. The rig has to be held against gravity rather than resting on it, water wants to run back out of the hole rather than into it, and there are two visible faces to leave tidy instead of one.
The most common use across the UAE is air conditioning. Split unit pipework, condensate drains and extract all need through-wall penetrations, and a condensate line drilled level instead of to a fall will back up into the room within a season. We set a fall to outside on every wet penetration as standard.
External walls add a second requirement. Any core through the building envelope is a route for water and for heat, so the annulus around the pipe has to be sealed properly once the service is in. We leave the opening in a condition the following trade can seal, and we will do the sealing ourselves if it is in our scope.
Applications
What we use it for
Air conditioning penetrations
Cores for split unit refrigerant lines, condensate drains and control cabling, drilled to a fall to outside.
Extract and ventilation
Through-wall openings for bathroom and kitchen extract, and for fresh air intakes on plant rooms.
Drainage through walls
Penetrations for waste and soil pipework passing horizontally through structural and party walls.
Electrical and data entries
Service entries through external walls for incoming supply, containment and communications.
Cavity and party walls
Cores through cavity construction where both leaves and the cavity have to be handled cleanly.
Balustrade and canopy fixings
Horizontal cores for structural fixings into walls and columns at consistent depth and level.
Sequence
How the job runs
Mark and check both faces
Position confirmed inside and out so the core lands where it should on the face you cannot see from where you are drilling.
Scan the wall
GPR run over the position to locate reinforcement and any services buried in the wall before the rig goes up.
Mount and drill to fall
Rig anchored or vacuum mounted, angle set for condensate fall where required, water fed and returned to a collector.
Make good and seal
Both faces dressed, opening sleeved or sealed as scoped, and the work area cleaned down.
Site control
Finished faces and why vacuum mounting matters
A core rig has to be held firmly to the wall or the barrel wanders and the hole comes out oval. The normal way to do that is to bolt an anchor into the face, which leaves a hole to fill afterwards. On a bare blockwork wall that is irrelevant. On finished plaster, cladding, marble or a painted feature wall it is a repair job that costs more than the core.
Where the face is finished, we vacuum mount instead. The rig is held by suction against the surface, so nothing is bolted into the wall and there is nothing to make good afterwards. It takes longer to set up and it needs a sound flat surface, which is why we check the face at survey rather than discovering it on the day.
The same thinking applies to water. On a finished interior we collect the return water at the barrel rather than letting it run down the wall, because slurry stains on a light finish are permanent.
Questions