How Load Shedding Affects Construction Projects

Building in the Dark

Across South Africa, building sites now plan around power cuts almost as much as around rain. Load shedding – Eskom’s controlled, scheduled power interruptions to protect the national grid – has become a daily reality. For anyone involved in a building project, from homeowners to large developers, this reality can be frustrating and expensive.

Modern construction depends heavily on reliable electricity: from mixing and pumping concrete to running cranes, power tools, site offices, and safety lighting. When the power drops, progress often stops. That is why *load shedding construction SA* is no longer a niche concern; it affects timelines, quality, labour efficiency, and budgets on projects of every size.

This article unpacks how load shedding disrupts construction timelines, threatens proper cement curing, causes project delays and labour inefficiencies, and drives budget overruns. It also offers practical strategies to plan around Eskom’s schedules and reduce the financial and structural risks on your site.

How Load Shedding Disrupts Construction Timelines

Direct interruptions to work

On a typical South African building site, most activities rely on electricity in some way:

- Concrete mixers and pumps - Tower cranes and hoists - Power tools (grinders, drills, saws, compactors) - Welders and cutting equipment - Site offices, printers, and communication systems - Temporary lighting and security systems

When a scheduled or unscheduled outage hits, these systems stop. Crews may be ready, materials may be on site, but without power, work slows to manual methods or halts completely. At higher stages of load shedding, this can happen several times a day.

For example, if the power goes off for two hours during a planned concrete pour, that window may be enough to miss a readymix delivery slot, lose a crane booking, or push the task into the next day.

Knock-on effects and cascading delays

The Eskom impact building projects experience is not just about the hours when the power is off. The knock-on effects can be larger than the immediate downtime:

- **Inspections delayed:** Municipal inspectors or engineers may not be able to assess work if lifts, lighting, or access equipment are down. Missed inspections can hold up the next trade. - **Subcontractors rescheduled:** Electricians, plumbers, tilers, and other trades often work in sequence. If one trade loses a day, the others may need to move to another site and only return days later. - **Deliveries postponed:** Load shedding at “robots” (traffic lights) causes heavy traffic. Readymix trucks, steel deliveries, and brick suppliers can be stuck for hours, missing their time slots.

Frequent short stoppages can be as damaging as one long delay because teams constantly start and stop tasks. Wet trades (like plastering and concrete), in particular, are sensitive to timing.

A six‑month project stretching to nine

Consider a small residential build planned for six months:

- The site loses an average of 1.5–2 hours per working day to Stage 4–6 outages. - Some key activities, like big concrete pours or crane lifts, get pushed out by 1–2 days each time they clash with load shedding. - Subcontractors shuffle between multiple sites, so when they miss a slot, they may only return the following week.

Over the life of the project, these small, repeated delays can easily add 6–10 weeks. A six‑month programme can stretch to eight or nine months, even if everyone is working hard. This is a major contributor to construction delays South Africa is currently experiencing across the industry.

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Cement Curing and Structural Quality Risks

How cement and concrete curing works

Concrete does not “dry”; it cures. Cement reacts chemically with water (a process called hydration) to gain strength over time. For this reaction to happen properly, concrete needs:

- Correct mix proportions - Proper placing and compaction - Adequate curing conditions (moisture and temperature) - Protection from early disturbance

While curing continues for weeks and months, the first 24–72 hours are particularly important for structural performance and crack control.

Where load shedding can cause problems

Load shedding impact on construction is most serious when it interferes with critical concrete operations:

- **Mixing and pumping:** If a mixer or pump stops mid‑pour, concrete can start setting in the pipeline or truck. Restarting may cause blockages or force the contractor to dump partially set concrete. - **Vibration (compaction):** Concrete must be vibrated to remove air pockets. If power fails during vibration, some areas may be under‑compacted, leading to honeycombing (voids) and weak spots. - **Continuous pours:** Structural elements like slabs, beams, and columns often need to be poured continuously. If a long gap occurs because a truck is delayed by traffic during load shedding at robots (traffic lights), “cold joints” can form – weak planes between old and new concrete. - **Early curing:** If pumps and water systems fail, planned curing (e.g., regular wetting or curing compound application) can be interrupted, increasing the risk of surface cracking.

This does not mean every outage will ruin concrete, but unplanned interruptions at the wrong time can compromise strength and durability.

Readymix deliveries and traffic delays

When traffic lights are out, roads around cities and towns clog up. Readymix trucks stuck in traffic may arrive on site much later than planned. Concrete has a limited workable time in the drum. If this is exceeded, the mix may:

- Be too stiff to place and compact properly - Require extra water on site (which weakens the mix) - Need to be rejected, causing expensive waste and delays

Practical tips for safer concrete work

To manage cement curing during load shedding:

- **Plan pours around schedules:** Check published load shedding schedules and avoid starting critical pours just before a known outage window. - **Use admixtures where appropriate:** Retarders or plasticisers (added chemicals) can extend workable time or improve workability. Always follow an engineer’s or supplier’s advice. - **Provide backup power for key steps:** A small generator dedicated to vibrators, pumps, or curing pumps can make a big difference to quality. - **Have contingency plans:** If a truck is badly delayed, know in advance whether you will reject the load, split the pour, or delay the rest of the work – and document the decision.

Where structural elements are involved, consult the engineer. The stakes are too high to guess.

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Labour Efficiency and On-Site Productivity

Idle crews and wasted hours

When power tools, mixers, hoists, or lighting go down, crews often stand idle. While some manual tasks can continue, productivity drops sharply. A team that could complete a full floor of formwork or plastering in a day may only manage half.

On a Stage 4–6 day, a site might lose:

- 2–4 hours of effective working time - Additional time to restart equipment, re‑set up tools, and re‑brief teams after each outage

The result is that a full day’s labour may only deliver half a day’s output.

Morale, start–stop cycles, and safety

Frequent stop–start cycles affect morale. Workers may:

- Rush to “catch up” when power returns, increasing mistakes and safety risks - Become frustrated when carefully prepared tasks are repeatedly interrupted - Lose focus while waiting, then take time to get back into rhythm

Safety is also affected:

- Poor or no lighting limits work to daylight hours and makes evening work risky. - Security systems (electric fences, cameras, alarms) may be down, affecting both site safety and material theft risk.

Administrative overhead

Site management spends more time:

- Replanning daily activities around Eskom schedules - Phoning subcontractors to shift times - Updating homeowners or developers on changed dates

These tasks do not directly build anything, but they consume hours and management attention, reducing overall efficiency.

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Project Delays and Contractual Complications

From operational disruption to formal delays

Repeated power cuts accumulate into significant programme delays. On formal contracts, this can trigger:

- **Extension of time (EOT) claims:** Contractors request more time to complete the works without penalties. - **Disputes:** Clients may question whether load shedding is a valid reason, or argue that the contractor should have planned better. - **Penalties or liquidated damages:** If delays are not properly documented and agreed, contractors can be hit with penalties for late completion.

Contract clauses and risk allocation

Standard South African contracts such as JBCC or NEC‑type agreements usually have provisions for unexpected events (often called force majeure or compensation events). However, because load shedding is now common, some parties argue it is a “known risk” rather than an unforeseen event.

To reduce disputes:

- **Include specific load shedding clauses:** Clearly state whether load shedding is treated as a delay event, how EOT and costs will be handled, and what backup measures are expected. - **Document impacts:** Keep records of outage times, affected tasks, and costs. This evidence is essential if claims arise. - **Agree responsibilities upfront:** Decide who pays for generators, fuel, and related costs before the project starts.

Treat load shedding as a predictable risk that must be managed and documented, not an excuse raised after the fact.

*(This article provides general information only and is not a substitute for professional legal or contractual advice.)*

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Budget Overruns and Hidden Costs

Direct extra costs

The most visible costs of building during load shedding include:

- Generators (purchase or rental) - Diesel or petrol for generators - Generator maintenance and repairs - Temporary lighting and cabling - Inverter and battery systems for offices and critical equipment - Additional security measures when systems are offline

These items can add a significant line to the budget, especially on longer projects.

Indirect and “invisible” costs

Less obvious but often larger are the indirect costs:

- **Extended preliminaries:** Site establishment, supervision, toilets, fencing, and insurance all run for longer when the project is delayed. - **Overtime and weekend work:** To catch up after outages, crews may be asked to work overtime, attracting premium rates. - **Rework:** Poorly timed concrete pours or rushed work can lead to defects that must be fixed later. - **Penalties and lost income:** Late completion can trigger contractual penalties or delay rental and sales income for developers or homeowners.

How small daily losses add up

Imagine a project with a R5 million construction budget and a planned duration of 8 months:

- The site effectively loses 1.5 hours per 8‑hour day to load shedding and disruptions – nearly 20% of productive time. - To maintain progress, the contractor installs a mid‑size generator and spends several thousand rand per month on diesel. - The project overruns by 6–8 weeks, adding extra site supervision, security, and rental costs.

By the end, total costs might increase by 10–15% or more, even without major disasters. This is why generator costs construction site budgets must be considered from the outset, not added as an afterthought.

Practical Strategies to Mitigate Load Shedding Risks

Plan around schedules and critical activities

- Monitor published Eskom and municipal load shedding schedules. - Avoid scheduling critical activities (large pours, crane lifts, key inspections) in known outage windows. - Build contingency time into the programme for high‑risk tasks.

Use backup power strategically

Rather than trying to power the entire site:

- Prioritise critical equipment: concrete vibrators, pumps, hoists, small tools, and essential lighting. - Use inverters and batteries for offices, Wi‑Fi, and communication systems. - Size generators correctly and maintain them; a failed generator during a pour can be worse than no generator at all.

Adjust working hours where feasible

- Start earlier or finish later to shift the main productive window outside peak outage times, where labour laws and agreements allow. - Consider Saturday work to recover lost time, with clear agreements on overtime rates.

Strengthen contracts and record‑keeping

- Include clear clauses on load shedding, extension of time, and cost‑sharing. - Keep a simple delay log: date, time, load shedding stage, affected activities, and cost or time impact. - Share this log with clients or developers to maintain transparency.

Communicate with stakeholders

- Inform homeowners and investors upfront that load shedding is a risk to programme and cost. - Provide regular updates on how outages are affecting progress and what mitigation steps are in place. - Use simple explanations; not all stakeholders are familiar with technical construction terms.

Tighten quality control

- Pay extra attention to concrete work done near outage times. - Record mix designs, delivery times, temperature, and any interruptions. - Ask the engineer or concrete supplier for guidance when outages clash with planned pours.

Plan for Load Shedding, Don’t Just React

Load shedding now shapes almost every aspect of building in South Africa. It disrupts timelines, complicates cement curing, reduces labour efficiency, creates formal project delays, and drives budget overruns.

However, while the risk is real, it is also largely predictable. Treating *load shedding construction SA* as a known constraint – like weather or site access – allows contractors, homeowners, and developers to plan, budget, and manage it.

By understanding the specific ways Eskom impact building projects, strengthening contracts, investing in targeted backup power, and planning critical activities carefully, construction projects can still succeed. Working with experienced professionals who know how to build in this environment is now more important than ever.

With proactive planning instead of reactive firefighting, South African building projects can reach completion safely, legally, and as close to time and budget as current conditions allow.