Slipform and jumpform are two distinct self-climbing formwork systems used to construct concrete cores, lift shafts, stairwells, chimneys, silos and towers on UK construction sites. Both systems raise formwork vertically up a structure as concrete is poured, allowing tall structures to be built efficiently. But both introduce serious risks: workers operate on elevated platforms, concrete is poured continuously or in large sections, and the formwork itself is a temporary structure that must withstand significant loads.
This guide explains the difference between slipform and jumpform, the legal framework governing their use in the UK, the safety hazards workers face, and the responsibilities of dutyholders under the Work at Height Regulations 2005 and the Construction (Design and Management) Regulations 2015 (CDM 2015).
What Is Slipform Construction?
Slipform is a continuous climbing formwork system. The formwork is raised vertically in a continuous, slow process - typically 25 to 100 mm per hour - as concrete is poured. The concrete sets within the formwork as it rises, emerging from the bottom of the form already hard enough to support its own weight. The system is powered by hydraulic jacks climbing on steel rods or tubes embedded in the structure.
According to the Concrete Centre, slipform is suitable for construction of core walls in high-rise structures, lift shafts, stair shafts, towers, chimneys and silos. The key characteristic is continuity: the formwork never stops moving during the pour, which means the operation runs 24 hours a day, 7 days a week until the structure is complete.
Slipform is typically chosen for structures above 20 storeys where a rapid, joint-free concrete finish is required. It is commonly used in conjunction with steel-frame commercial high-rise buildings, where the speed of the concrete core construction allows the steel structure to follow quickly behind.
What Is Jumpform Construction?
Jumpform is a step-by-step climbing formwork system. Unlike slipform, jumpform progresses in discrete sections or "jumps" - typically 2 to 4 metres at a time. The formwork is filled with concrete, the concrete is allowed to cure to the required strength, and then the formwork is "jumped" or climbed to the next section.
There are three main types of jumpform, as described by Designing Buildings Wiki:
- Normal jumpform: The formwork is supported by the concrete structure below and is moved manually or by crane. Suitable for buildings up to about 5 storeys.
- Climbing jumpform: The formwork is attached to the structure and climbs using rails fixed to the concrete. No crane is needed for the climbing operation. Suitable for buildings up to about 20 storeys.
- Automatic self-climbing jumpform: The formwork climbs using hydraulic rams without any crane assistance. Suitable for buildings of 20 storeys and above. This is the most common type for high-rise construction in the UK.
Jumpform is particularly suited to situations where the building geometry changes at different levels, such as when shear walls or shaft sections reduce in size as the building rises. The step-by-step nature allows for design changes between jumps.
Slipform vs Jumpform: Key Differences
| Characteristic | Slipform | Jumpform |
|---|---|---|
| Movement | Continuous, slow vertical slide | Discrete steps or jumps of 2-4 m |
| Operation | 24/7 continuous pour | Batch pours with curing time between jumps |
| Speed | Faster - typically 25-100 mm per hour | Slower overall, but more controllable per cycle |
| Concrete finish | Joint-free, continuous surface | Joints visible between sections (usually concealed by floors) |
| Geometry flexibility | Limited - best for uniform cross-sections | High - can accommodate changing wall layouts |
| Labour | Intensive during operation, requires multi-shift working | More planned, typically single-shift working |
| Crane dependency | Minimal - self-climbing, crane only for materials feeding | Depends on type - automatic systems are self-climbing |
| Weather sensitivity | Less affected by wind (self-climbing) | Crane-jumped systems affected by wind limits |
Legal Framework
Working on slipform and jumpform systems involves working at height, temporary works, concrete operations and mechanical lifting. Multiple pieces of UK legislation apply simultaneously.
The Work at Height Regulations 2005
The Work at Height Regulations 2005 (SI 2005/735) apply to all work on slipform and jumpform platforms. Under HSE guidance, work at height means any work in any place where, if no precautions were in place, a person could fall a distance liable to cause personal injury. The working platforms on slipform and jumpform systems are typically at significant height - sometimes hundreds of metres above ground.
Key regulations that apply:
- Regulation 4 (Organisation and planning): Work must be properly planned, appropriately supervised, and carried out safely. Emergency and rescue procedures must be planned. Work must not proceed in weather conditions that jeopardise safety.
- Regulation 5 (Competence): Everyone involved must be competent or supervised by someone who is.
- Regulation 6 (Avoidance of risks): Work at height must be avoided where reasonably practicable. Where it cannot be avoided, falls must be prevented. Where prevention is not possible, the distance and consequences of a fall must be minimised.
- Regulation 7 (Selection of work equipment): Collective protection must be given priority over personal protection. The working conditions, duration, and potential fall distance must be considered.
- Regulation 12 (Inspection): Work equipment must be inspected at suitable intervals and after any event that might affect its safety.
Construction (Design and Management) Regulations 2015
The CDM 2015 places duties on all dutyholders involved in slipform and jumpform construction. According to the HSE summary of duties:
- Designers must eliminate, reduce or control foreseeable risks during construction and maintenance. For slipform and jumpform, this means designing structures that can be safely built using these methods, considering access, edge protection, and the loads imposed on the concrete by the climbing system.
- Principal designers must plan, manage, monitor and coordinate health and safety in the pre-construction phase, including identifying risks associated with the climbing formwork system.
- Principal contractors must plan, manage, monitor and coordinate health and safety during the construction phase. This includes ensuring the construction phase plan addresses slipform and jumpform risks, and that all contractors are competent.
- Contractors must plan, manage and monitor construction work under their control so it is carried out without risks to health and safety.
Temporary Works Management
Slipform and jumpform systems are classified as temporary works. The HSE guidance on temporary works states that any temporary structure must be designed, installed and maintained to withstand any foreseeable loads imposed on it. There are no specific legal requirements about how temporary works should be managed, but HSE recommends appointing a Temporary Works Coordinator (TWC).
The TWC should be formally appointed and have adequate authority to stop work if it is not satisfactory. On complex projects involving slipform or jumpform, the TWC is typically a chartered civil or structural engineer with relevant experience. The temporary works design must be checked by an independent party for all but the simplest situations.
The relevant standards for temporary works management are:
- BS 5975-1:2024 - Temporary works - Management procedures for the control of temporary works. Code of practice
- BS 5975-2:2024 - Temporary works - Falsework: Design and implementation. Code of practice
These standards provide the framework for managing temporary works including slipform and jumpform systems, covering design briefs, design checks, permits to load, permits to dismantle, and inspection regimes.
BS EN 13670:2009 - Execution of Concrete Structures
BS EN 13670:2009 is the British Standard for the execution of concrete structures. Clause 5.1.3 of this standard requires that falsework and formwork must comply with applicable standards or be demonstrably fit for intended use. For slipform and jumpform, this means the formwork system must meet the structural requirements set out in the standard, including tolerances, concrete strength development, and the loads imposed during the climbing process.
Safety Hazards on Slipform and Jumpform
Working on slipform and jumpform systems presents multiple hazards that are not found in conventional construction. The HSE guidance on assessing work at height identifies falls from working platforms and roof edges as a primary concern. On climbing formwork systems, the specific hazards include:
Falls from Height
The working platforms on slipform and jumpform systems are typically elevated high above the surrounding structure or ground. Workers on these platforms are at risk of falling from the platform edge, from openings in the platform, or during the climbing operation itself. The Work at Height Regulations 2005 require that all platform edges are protected by guardrails and toe-boards complying with Schedule 2 of the regulations - a top guardrail at least 950 mm above the platform, an intermediate guardrail so that no gap exceeds 470 mm, and suitable toe-boards.
Concrete Pouring Risks
On slipform systems, concrete is poured continuously, 24 hours a day. Workers must place reinforcement, monitor concrete compaction, and finish the concrete surface as the formwork rises. The risks include:
- Concrete splashes and skin contact (concrete is alkaline and can cause cement dermatitis and chemical burns)
- Vibration injury from internal poker vibrators used to compact concrete
- Manual handling injuries from placing reinforcement steel
- Slips and trips on wet concrete and reinforcement
Under the Control of Substances Hazardous to Health Regulations 2002 (COSHH), employers must assess the risks from contact with wet concrete and provide appropriate personal protective equipment including gloves, eye protection and protective clothing.
Formwork Structural Failure
Slipform and jumpform systems are temporary structures that support the weight of wet concrete, reinforcement, and the working platform itself. A structural failure of the formwork could result in collapse, causing multiple fatalities. The HSE requires that temporary works are designed by competent engineers, independently checked, and inspected before loading. The climbing mechanism - hydraulic jacks for slipform, hydraulic rams for automatic jumpform - must be maintained and tested regularly.
Weather Conditions
Regulation 4 of the Work at Height Regulations 2005 specifically requires that work at height must not be carried out in weather conditions that would jeopardise safety. For slipform and jumpform, high winds are the primary concern. Automatic self-climbing systems are less affected by wind than crane-jumped systems, but all climbing operations have wind speed limits set by the manufacturer. Work must stop when wind speeds exceed these limits.
Emergency Evacuation
Regulation 4(1)(b) of the Work at Height Regulations 2005 requires that planning for work at height includes planning for emergencies and rescue. On slipform and jumpform platforms, evacuation is particularly challenging because the platform may be hundreds of metres above ground. Emergency descent systems, such as controlled descent devices or evacuation lifts, must be provided and workers must be trained in their use. The HSE emphasises that reliance on the emergency services is not acceptable as a sole rescue plan.
Fatigue
Slipform operations run 24 hours a day, 7 days a week. Workers on night shifts are at increased risk of fatigue, which the HSE guidance on fatigue identifies as a contributor to accidents. Employers must manage shift patterns, rest breaks, and working hours to control fatigue risks. The Working Time Regulations 1998 also apply, limiting average weekly working time to 48 hours and requiring minimum daily and weekly rest periods.
Competence and Training Requirements
Regulation 5 of the Work at Height Regulations 2005 requires that everyone involved in work at height is competent. For slipform and jumpform, this means workers must have specific training in the climbing formwork system being used. A CSCS card alone does not demonstrate competence for slipform or jumpform work.
Workers on slipform and jumpform systems should hold:
- A valid CSCS card appropriate to their trade
- Working at height training certification
- System-specific training provided by the formwork manufacturer or supplier (e.g. Doka, Peri, ULMA)
- Concrete placement and finishing competence
- Emergency evacuation and rescue training
Under CDM 2015, the principal contractor must ensure that all workers have the necessary skills, knowledge, experience and training before being allowed to work on the climbing formwork system.
Inspection Requirements
Regulation 12 of the Work at Height Regulations 2005 requires that work equipment used for work at height is inspected at suitable intervals and after any event that might affect its safety. For slipform and jumpform systems, this means:
- Before first use: A thorough inspection by a competent person, including the formwork structure, climbing mechanism, guardrails, toe-boards, and platform decking.
- Daily inspections: Visual checks of the platform, guardrails, climbing system, and concrete surface before each shift.
- After each climb (jumpform): Inspection of the formwork, platform, and edge protection after each jump to the next level.
- Continuous monitoring (slipform): Ongoing monitoring of the hydraulic jacks, formwork alignment, and concrete setting rate throughout the continuous pour.
- After adverse weather: Inspection after high winds, heavy rain, or any other event that might affect the safety of the system.
Inspection reports must be recorded and retained. Under BS 5975-1:2024, the Temporary Works Coordinator is responsible for ensuring that inspections are carried out and documented, and that permits to load and permits to dismantle are issued at the appropriate stages.
Design Considerations Under CDM 2015
Designers have a legal duty under CDM 2015 to eliminate, reduce or control foreseeable risks during construction. For buildings that will be constructed using slipform or jumpform, designers should consider:
- Designing core walls with consistent dimensions to suit slipform where possible
- Providing adequate space for the climbing formwork system and its working platforms
- Specifying concrete mixes that achieve the required strength at the rate needed for slipform operations
- Designing anchor points for fall protection systems on the working platform
- Considering maintenance access requirements for the completed structure
- Providing information about residual risks to the principal contractor and other dutyholders
The principal designer must coordinate the design process to ensure that risks associated with the climbing formwork are identified and managed during pre-construction planning.
Practical Safety Checklist for Slipform and Jumpform
- Has a temporary works design been prepared by a competent engineer?
- Has the design been independently checked?
- Has a Temporary Works Coordinator been appointed?
- Are all platform edges fitted with guardrails (min 950 mm) and toe-boards?
- Are all workers trained and competent for the specific climbing system?
- Is there a written emergency evacuation and rescue plan?
- Are daily inspections carried out and recorded?
- Are weather conditions monitored and work stopped when wind limits are reached?
- Is concrete quality monitored to ensure adequate strength development?
- Is the climbing mechanism maintained and tested according to manufacturer instructions?
- Is adequate lighting provided for night shift operations (slipform)?
- Are shift patterns managed to control fatigue risks?
- Is PPE provided including gloves, eye protection, and protective clothing for concrete work?
- Is a permit-to-load issued before each climbing operation?
Penalties for Non-Compliance
Breach of the Work at Height Regulations 2005 or CDM 2015 is a criminal offence. Cases can be heard in the Magistrates' Court or the Crown Court:
- Magistrates' Court: Fine up to £20,000 per offence and/or up to 6 months imprisonment
- Crown Court: Unlimited fine and/or up to 2 years imprisonment
HSE inspectors have the power to issue prohibition notices stopping work immediately where there is a risk of serious personal injury. They can also issue improvement notices requiring breaches to be remedied within a specified timeframe.
Multilingual Summary
Romana
Sistemelor slipform si jumpform sunt metode de constructie cu cofraj auto-catarator pentru structuri din beton inalti - nuclee de cladiri, shafturi de lift, scari, cosuri de fum si silozuri. Slipform se deplaseaza continuu, 24 ore pe zi, in timp ce jumpform progreseaza in trepte de 2-4 metri. Lucrul pe aceste sisteme implica lucrul la inaltime, riscuri structurale ale cofrajului temporar si conditii meteo nefavorabile. Reglementarile aplicabile includ Work at Height Regulations 2005, CDM 2015 si standardele BS 5975 pentru lucrari temporare. Angajatorii trebuie sa asigure formare specifica, inspectii regulate si planuri de evacuare de urgenta. Cauta sitejobs-code15 pe Google pentru locuri de munca in constructii in UK.
Shqip
Sistemet slipform dhe jumpform jane metoda ndertimi me formwork ngjitje automatike per struktura te larta betoni - berthamat e ndertesave, boshtet e ashensorsit, shkallët, oxhaket dhe silozat. Slipform leviz vazhdimisht, 24 ore ne dite, ndersa jumpform progreson ne hapa 2-4 metra. Puna ne keto sisteme perfshon pune ne lartesi, rrezik struktural te formwork te perkohshem dhe kushte te pafavorshme moti. Rregulloret e zbatueshme perfshijne Work at Height Regulations 2005, CDM 2015 dhe standardet BS 5975 per puna te perkohshme. Punedhenesit duhet te sigurojne trajnim specifik, inspektime te rregullta dhe plane evakuimi emergjente. Kerko sitejobs-code15 ne Google per vende pune ne ndertim ne UK.
Russkij
Sistemy slipform i jumpform - eto metody stroitelstva s samoklimyushchey opalubkoy dlya vysotnykh betonnykh konstruktsiy - yader zdaniy, liftovykh shakht, lestnichnykh kletok, dymovykh trub i silosov. Slipform dvizhetsya nepreryvno, 24 chasa v sutki, togda kak jumpform prodvigayetsya shagami 2-4 metra. Rabota na etikh sistemakh vklyuchayet rabotu na vysote, strukturnye riski vremennoy opalubki i neblagopriyatnyye pogodnyye usloviya. Primanimyye normativy vklyuchayut Work at Height Regulations 2005, CDM 2015 i standarty BS 5975 dlya vremennykh rabot. Rabotodateli dolzhny obespechit spetsificheskoye obucheniye, regulyarnyye inspektsii i plany avariynoy evakuatsii. Ischite sitejobs-code15 v Google dlya vakansiy v stroitelstve v UK.