Project: Suspended Slab Propping, Column Demolition & Structural Steel Installation
Location: Sydney
Sector: Commercial Construction
Services Provided: Temporary Works Engineering, Propping Design, Equipment Supply
Equipment Used: Legend Multiprops, Hardwood Timber Sleepers
Project Overview
A commercial construction project required the safe removal of a concrete columns to make way for a new structural steel beam. With a suspended concrete slab bearing directly onto the column, uncontrolled removal would have transferred load without adequate support, creating structural and safety risk.
Legend Hire’s engineers designed a temporary propping system using Legend Multiprops and hardwood timber sleepers to provide continuous vertical load transfer beneath the slab throughout the demolition sequence. The solution enabled the contractor to safely remove the column, install the structural steel beam, and complete the works without incident.
The Challenge
The project required the removal of a load-bearing concrete column to accommodate a new structural steel beam as part of a commercial building modification. The suspended concrete slab bearing on the column could not be left unsupported during demolition, any uncontrolled load redistribution risked slab deflection or structural failure during the works.
Site conditions added to the complexity. Poor access within the work zone restricted equipment movement and placement, while variable soil conditions at the bearing area required careful consideration when designing the temporary base. The propping system needed to be engineered to safely carry and transfer slab loads throughout the full demolition and steel installation sequence.
This project required a large-scale structural propping solution to ensure the safety of the residents while structural columns were removed.
The Solution
Legend Hire’s engineers designed a temporary propping system calibrated to the specific load requirements of the suspended concrete slab. Legend aluminum Multiprops were positioned in a coordinated layout directly beneath the slab soffit to provide continuous vertical support throughout the demolition works.
(Legend hire Multiprops are available in various height ranges – 0.8m to 6.250m. Fully meets AS/NZS 3610, AS/NZS 1576 & BS En 1065 Standards)
Hardwood timber sleepers were installed at the base of each prop to distribute loads across the available bearing area and compensate for the variable ground conditions on site. The prop layout and base bearing design were engineered to ensure the slab remained fully supported during column removal, structural steel beam installation, and load transfer back to the permanent structure.
(Available in 200mm x 100mm, with lengths ranging from 600mm to 2.4m)
Equipment was installed in direct coordination with the principal contractor’s demolition sequence to maintain safe working conditions at all stages. For other projects involving column works and structural modification, see Legend Hire’s engineered modular propping system for column works and engineered support system for demolition works.
Engineering Considerations
The engineering requirement was maintaining continuous load transfer through the temporary propping system from initial column saw-cutting through to final structural steel connection and prop removal. Load path continuity was the primary design constraint at every stage of the works.
Base bearing conditions were addressed through hardwood sleeper distribution, ensuring vertical loads from each prop were spread across an adequate area without exceeding the capacity of the substrate. The Legend Multiprop system provided the rated capacity and height adjustability required to suit the slab geometry and construction tolerances on this project.
Where projects involve similar load redistribution challenges during structural modification, Legend Hire’s temporary propping and hydraulic jacking solution and concrete slab load management case studies demonstrate comparable engineering approaches.
Equipment Used
Legend Multiprops – engineered modular propping system providing rated vertical load capacity and height adjustability, configured to suit the slab geometry and demolition sequence.
Hardwood Timber Sleepers – installed at prop bases to distribute point loads across the bearing area under variable ground conditions.
The Outcome
The temporary propping system maintained full structural support of the suspended concrete slab throughout the column demolition and structural steel installation sequence. The principal contractor safely removed the column, installed the new structural steel beam, and completed load transfer back to the permanent structure without incident.
The engineered propping layout eliminated uncontrolled structural risk during the critical demolition phase, enabling the project to proceed on programme under controlled, compliant conditions.
For related suspended slab support work, see Legend Hire’s suspended slab support during remediation works.
Frequently Asked Questions
Suspended slab propping is a temporary works method used to support an elevated concrete slab when the permanent structure beneath it, such as a column or beam is being removed, modified, or replaced. Engineered props transfer slab loads to a temporary bearing point until permanent structural support is reinstated.
Temporary propping is required whenever a load-bearing column is to be removed and the structural elements above it cannot safely redistribute load during the works. An engineered propping system must be designed and installed before demolition commences to carry the transferred loads throughout the sequence.
On sites with variable or poor soil conditions, propping base loads are distributed using hardwood timber sleepers or engineered spreader beams beneath each prop foot. This spreads concentrated vertical loads over a wider bearing area and prevents point load failure at ground level.
Legend Hire engineers specify equipment based on project-specific load requirements. For suspended slab propping on commercial projects, Legend Multiprops are commonly selected for their rated load capacity, adjustability, and modular configuration, allowing layouts to be tailored to slab geometry and the demolition sequence.