Loadbearing structures — primary frame works
This stage covers installation of load-bearing walls, columns, beams, slabs, rough staircases and primary steel structures. Work focuses on achieving design geometry, structural capacity and reliable joints while preventing cracks and corrosion. Key activities include formwork and shoring, reinforcement placement, concrete casting or steel erection, embedment of anchor items and interim inspections. Coordination with geotechnical, structural and MEP teams and strict control of tolerances, curing and temporary supports is common practice to reduce rework and ensure structural integrity.
Why this stage becomes expensive when missed
Overview
The structure stage implements the primary load-bearing system defined by design documents. Typical tasks include erecting formwork and shoring, fixing reinforcement to specified cover and geometry, placing concrete of the required grade or assembling prefabricated elements, and installing embedded items and connections. Sequence and temporary works are coordinated to control deflections and load transfer during construction. Inspections and tests — reinforcement checks, concrete sampling, weld and bolt inspections — are used to confirm compliance. Attention to interface details with MEP, tolerances for finishes and corrosion protection for exposed steel reduces later remediation. Proper documentation of as-built geometry, test results and deviations supports handover and future maintenance planning.
High-cost mistakes in this stage
- Incorrect geometry or out-of-tolerance elements leading to rework
- Insufficient reinforcement, wrong lap lengths or cover
- Poor concrete compaction, curing or honeycombing
- Improperly detailed or executed joints and anchors
- Missed embed positions or mislocated openings
- Inadequate corrosion protection for steel elements
Linked error scenarios
Work includes constructing load-bearing masonry or cast-in-place concrete walls and vertical enclosure elements with control of geometry and tolerances. Activities cover formwork, reinforcement where required, joint detailing and provision for openings and interfaces. Surveys and step-by-step checks ensure plumb, alignment and correct positioning of embeds. Proper curing and moisture control reduce risk of early-age cracking and ensure intended capacity.
Likely failure mode
- Walls out of plumb or uneven surface levels
- Insufficient vertical reinforcement or poor lap details
- Incorrect location or sizing of openings and embeds
Why it becomes expensive late
Before work is covered up by structure or rough finishes. Late-fix multiplier: 2-5x. Delay exposure: 10-24 days.
Control signal
- Verify wall alignment and level tolerances before progressing
- Confirm reinforcement layout, anchors and cover
- Check joint and opening positions against drawings
Interstorey slabs and floor plates are constructed by in-situ casting or by placing precast units. Controls include slab thickness, reinforcement layout, deflection limits and compaction. For multi-storey sequencing, shoring removal times and load path checks are planned to avoid progressive deformation. Curing and surface tolerance checks ensure long-term serviceability.
Likely failure mode
- Uneven slab levels or incorrect falls
- Insufficient top or bottom reinforcement leading to cracking
- Premature shoring removal causing deflection
Why it becomes expensive late
Before work is covered up by structure or rough finishes. Late-fix multiplier: 2-5x. Delay exposure: 10-24 days.
Control signal
- Confirm slab thickness and reinforcement cover before pouring
- Check temporary shoring layout and load paths
- Inspect curing regime and surface condition after stripping
This work covers installation of embed plates, anchor bolts, connection nodes and junctions between structural elements. Accurate placement and correct specification of anchor types and welding are critical to transfer loads as designed. Coordination with finish trades and services reduces clashes and ensures that embeds are protected until final finishes are applied.
Likely failure mode
- Mislocated embeds or incorrect anchor types
- Insufficient weld or bolt capacity at connection nodes
- Clashes with MEP services or finishes
Why it becomes expensive late
Before work is covered up by structure or rough finishes. Late-fix multiplier: 2-5x. Delay exposure: 10-24 days.
Control signal
- Verify embed positions with layout surveys before casting
- Check anchor type, length and installation method
- Inspect welds and bolt installation at connections
Related glossary
Steel elements that increase concrete tensile capacity.
Specified compressive strength class of concrete.
Move from risk to action
Use the linked checklist before sign-off, then return to the stage guide to align decisions with budget logic and work-package scope.