Stitch Core Drilling:
Lift Shaft Opening
in a Concrete Slab

Introduction

Creating a lift shaft opening in an existing building is not a job for standard demolition methods. When a commercial office building in Central Johannesburg required a precise opening through a 250mm reinforced concrete slab, the project demanded a specialist approach.

The building was fully operational, the structure needed to remain intact, and the opening had to match exact engineering specifications. This is where VUS Core Drilling delivered a professional solution using stitch core drilling — a method designed for accuracy, minimal disruption, and structural safety.

What Is Stitch Core Drilling?

Stitch core drilling is a specialised concrete cutting method used to create large openings in slabs, walls, and floors. Instead of using breakers or saws, a series of overlapping core holes are drilled along the outline of the required opening. Once complete, the internal section is removed, leaving a clean, precise cut.

This method is the go-to solution when:

• The opening is too large for a single core drill
• Reinforced concrete must remain structurally sound
• Low vibration is critical in occupied buildings
• Clean, accurate edges are required to meet engineering spec

Learn more about our full range of concrete cutting and core drilling services available across Gauteng.

The Project: Lift Shaft Opening in a Johannesburg Office Block

This project involved cutting a large rectangular lift shaft opening through a 250mm reinforced concrete slab in a multi-storey commercial office building in Johannesburg CBD.

Key Challenge 1 — Reinforced Concrete Slab

At 250mm thick with steel reinforcement throughout, the team needed precise depth control and continuous water cooling to navigate the rebar while keeping the surrounding slab structurally intact.

Key Challenge 2 — Active Commercial Environment

The floor below was occupied retail space. The project required strict dust control, minimal noise disruption, and careful debris management throughout the duration of the work.

Key Challenge 3 — Zero Margin for Error

The opening had to align perfectly with the lift shaft engineering specifications — precise dimensions, straight edges, no cracking into the surrounding slab.

How We Executed the Project

To ensure accuracy and efficiency, we used the Hilti DD350 core drilling system — a professional-grade machine designed for heavy-duty concrete applications.

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Why Stitch Core Drilling Beats Demolition

Many contractors reach for a breaker or jackhammer when they need to open up a slab. On a job like this, that would have been the wrong move:

• Minimal vibration — protects surrounding structure, prevents collateral damage
• High precision — the opening matches exact engineering specifications every time
• Structural integrity maintained — no unnecessary cracking or weakening of the slab
• Cleaner work environment — less dust, less debris, faster clean-up
• Ideal for occupied buildings — minimal disruption to tenants throughout

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Why Choose VUS Core Drilling in Johannesburg?

With over 15 years of combined industry experience, VUS Core Drilling has built a reputation for precision, reliability, and safety across Gauteng. We've been trusted on major infrastructure including the Rea Vaya BRT stations and Gautrain stations in Sandton and Johannesburg.

Our Concrete Cutting Services

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