What is Formwork or Formworking?

The past century has ushered in the rapid development of new technology, equipment and worksite safety for construction.

Heavy machinery reduces workloads; battery-powered tools assist tradesmen, and formwork technology has evolved. But what is formwork, and why is it so important?

What is Formwork?

Formwork is a permanent or temporary casing where fresh concrete is poured until it cures into the desired shape. The tried and tested process has persisted from ancient civilisation to modern times.

Formwork structures should retain shape, remain braced and watertight, and be appropriately sized according to the scope of construction. It is vital that formwork can support the weight of wet concrete without strain.

Speed and safety on a construction site continue to improve as equipment and building materials evolve. As a result, workers have access to an array of safer, cheaper, and more robust materials than before.

Now the construction industry can approach a job from multiple angles. Each new formwork system suits specific applications.

Workers choose based on project scope, budget, structure, and the surrounding environment. This is evident in the different categories of formwork available on the market.

Modular vs Regular

Formwork has a significant range of tools each suited for different uses. Traditional formwork and shuttering consists of plywood and timber structures. The choice of materials makes them essential and affordable. Traditional formwork is ideal for smaller residential projects as a result.

Modular systems have emerged over the last century and their popularity continues to skyrocket. The modular category comprises of steel, fabrics and plastics. Components arrive at sites ready for assembly.

The modular type of formwork is easy to use on larger worksites and consists of a single material. Both features make it a significant draw for large-scale concrete formwork.

Types of Formwork

Below we will explain the different concrete systems utilised on construction sites.

Timber Formwork

Out of all the types, timber formwork is one of the most widely used materials (and oldest) out of all types listed. Builders create these structures from lumber and plywood. It remains the preferential formwork type on smaller jobs where labour costs are lower than timber.

formwork timber setup
Figure 1: Timber formwork supported by H-Frame sets

Timber is a lightweight material to handle compared to its engineered counterparts. It is cost-effective on smaller projects, flexible and can be reused. Its flexibility stems from onsite fabrication.

Builders can shape the dimensions to whatever is required. Unfortunately, reusability is very limited in contrast to steel or aluminium.

Timber formwork is also time-consuming to construct and inappropriate for a large-scale project.

Engineered Formwork

Composed of steel or aluminium, engineered formwork involves connecting prefabricated components. Its modular capability allows easy assembly and makes it viable on large-scale construction sites.

engineered steel formwork
Figure 2: Steel formwork module

Because of its material, engineered formwork has high durability and low maintenance cost. These qualities give it the highest reusability rate out of any current process.

Steel formwork offers a smoother surface finish over timber for concrete. It has many applications, including curved structures such as sewers and tunnels. The components are completely waterproof, preventing honeycomb headaches.

Despite the overwhelming advantages, using steel or aluminium to support small residential sites is ineffective and a waste of resources. It is not practical or cost-effective for every job, so companies reserve it for large-scale endeavours.

Aluminium builds are more lightweight and cost-effective than steel. Unfortunately, they cannot be altered once erected. Furthermore, aluminium is slightly weaker than steel.

Insulated Formwork

Insulated formwork is an interlocking, modular design cut from Insulated Concrete Forms (or ICF) and assembled on-site. Its popularity is only now rising among formwork companies and sites, especially in housing.

Many are beginning to capitalise on the process as its environmental and practical savings. This will only speed up as it becomes widespread knowledge in the concrete formwork community.

insulated formwork setup
Figure 3: Poured concrete supported by ICF

Insulated formwork offers an array of benefits not present in alternatives. ICF improves building safety with its fire-resistant material. The nature of the design provides houses with improved acoustic and thermal insulation. Similar to engineered counterparts, ICF is durable and easy to use and assemble.

Fabric Formwork

As its name hints, this fabric-like structure can mould concrete into any shape, no matter how abstract. It’s the next step in complex concrete structures as technology, and the construction industry evolves.

fabric formwork setup
Figure 4: Fabric Formwork (source: https://www.eurekalert.org/)

Plastic Formwork

Plastic alternatives combine an interlock system with a lightweight material. The outcome is a formwork that can withstand over 100 uses. The rapidly growing product is popular on residential sites. Its application in large-scale commercial projects is non-existent.

Plastic formwork is extremely lightweight and easy to handle and assemble. In addition, sheets are highly cost-effective because of their reusable nature.

plastic formwork assembly
Figure 5: Plastic formwork setup (source: https://www.designindaba.com/)

Difference Between Shuttering and Formwork

Formwork and shuttering are essential in concrete construction. Certain individuals view the terms as identical while others recognise their distinct features. Both parties are in the right to an extent.

Formwork describes the overall process of moulding concrete into a shape using a variety of materials whereas shuttering is where workers use plywood or similar materials to mould the concrete until it has cured.

While formwork focuses on the overarching process, shuttering focuses on vertical arrangements. Vertical moulds include columns and retainer walls. Ultimately, both accomplish the same task in concrete formwork.

Types of shuttering

A variety of shuttering techniques exist that possess their own benefits and downsides. Choosing which type of formwork to use will depend on cost and time.

Timber Shuttering

Timber remains popular for its flexibility across any worksite and on vertical concrete work. They also act as excellent bracing atop of shoring systems.

Plywood Shuttering

The argument can be made for plywood being the most popular for its cheap price and reusability. Concreters need water-resistant as most projects occur outdoors. Water resistance assists the plywood to withstand moisture from the concrete and air. Formply is a popular choice for its laminated surface that provides a smooth finish when removed.

Steel shuttering

Steel plates are manufactured to any desired shape and size. Steel plates are ideal for curved structures and large-scale construction projects. Steel components offer the highest reusability rate of all shuttering materials. The downside of steel is that they are not cost-effective for smaller worksites.

The use of shuttering and formwork techniques will depend on the projects scale. A Highrise, for example, will employ a variety of necessary techniques. Constructing a concrete building without shuttering is an impossible task. Shuttering without proper care will only undermine the structure’s integrity in the future.

Centering & Staging

Centering supports horizontal slabs and is another extension of formwork. Slabs are held using falsework shoring frames and props.

Staging refers to the steel components that act as supports for all formwork while the concrete dries. The temporary supports are falsework systems including props, H-Frames and V-Frames kits. Installing the falsework is quick thanks to the modular nature of the components. Shoring kits include modular components made up of frames, bracing, U-heads and Base Jacks. The modular nature of the shoring kits allows for easy dismantling once the concrete has set.

Temporary Falsework Structure
Figure 6: Falsework systems acting as a temporary structure until the concrete dries

The overall difference in formwork and shuttering is minimal to the point that many consider them the same.

Why is it Important?

Formwork in construction is too vital and irreplaceable for numerous reasons. First, the process provides a minimal floor-to-floor construction cycle that reduces the timeline of a project. Site managers can mobilise and demobilise on time, saving time and money to allocate elsewhere.

It creates a quality finish to covered concrete surfaces. The higher the quality of formwork employed, the smoother the finish. Most importantly, it enhances the safety of workers on site.

Once the concrete has hardened, builders gain access to solid surfaces. Additionally, builders can now establish an elevated work platform through scaffold rigs.

Formwork is here to stay despite new technological advancements in building and construction. Through big and small differences, every type has its own unique advantages depending on the worksite and the scale of the structure.