Formwork Full Guide: All You Need to Know About it

Formwork refers to the process of making a temporary structure through which concrete can be moulded into the desired share. The method of making this structure includes pouring mixed concrete into the mould that is already in the preferred form. Also, there are two primary forms of formwork, namely the traditional formwork and the modern formwork. On the one hand, the conventional formwork is formed using timber wood or even steel, an alloy. Click here to read more about formwork in Sydney.

Other materials that are useful for traditional formwork are glass fibre reinforced plastic and other high-quality materials. A critical attribute of any material that will fit as a formwork frame is that it must be capable of carrying all the dead and live weight put on it. The formwork will bear any weight that is placed on it. This article is a comprehensive guide on the basic knowledge and application of formwork in modern construction.

Below are the detailed formwork types, their respective advantages and disadvantages, and their importance in general construction projects. Before we dive into the primary style of formwork, we need to give e more detailed description of the significance of formwork in both private and commercial constructions.

Properties of Formwork Materials

Formwork can come in different shapes, materials and containers, including scaffolding, falsework, shuttering, open-box containers in fresh concrete. In all these structures, the process requires pouring and compacting these materials into different desired moulds. The purpose of formwork is not to stand as a permanent structure on the project but to hold the concrete in shape over time. 

At the end, when the concrete is fully and permanently set, the formwork can be removed. At that point, a mass of concrete takes the shape of the inner form of the formwork. However, what is the essential properties of the formwork?

Properties of a suitable formwork

  • Any material that will serve as a formwork must be strong. It must also be able to resist the pressure and weight of concrete on it
  • The formwork material must be rigid enough to retain the shape of concrete without having to undergo any reformation or deformation
  • The formwork must not make too huge a difference to the project’s total cost in terms of the cost. Otherwise, it would not be an economically safe decision to include it. 
  • Formwork materials must be watertight enough to avoid any leakage at the joints. Also, the concrete mixture must not soak in water

Types of Formwork

The classification of formwork below is based on the materials from which they are made. 

  1. Timber formwork

Formwork that is made of timber is one of the most durable materials in the construction industry. Also, it is usually constructed on the site where wood is imported. However, the timber formwork can be classified in the details below:

  1. Lumber. Lumber refers to a commonly available material with a lot of strength. It also has a relatively higher weight and can cost a bit more as well.
  2. Plywood. The plywood source for formwork helps produce concrete, the formwork with the enhanced quantity of finished concrete.

Advantages of Timber formwork

  1. Timber formwork is easy to cut and trim into the desired shapes
  2. It also has an excellent thermal resistance that can prevent damage to the concrete, primarily when used in cold regions of the world
  3. Timber formwork can also be very light in weight, which makes its use very easy to handle, unlike the other materials
  4. When the timber formwork has fulfilled its purpose, it is the easiest to be dismantled at will

Disadvantages of Timber formwork

  1. One common demerit of using timber as formwork is that it cannot stand the test of time. This material has a somewhat restricted reuse factor.
  2. In addition, if the timber wood is dry, the timber formwork will absorb some moisture from the moist concrete. As a result, the water will weaken the strength of the obtained concrete structure
  3. Excess moisture content in the material leads to a shrinkage of the structure. As a result, the shrinkage can lead to leakage of the grout and the cup open joints of the system.
  1. Steel formwork

Another essential material that can serve in the making of formwork is the use of steel. Steel, as a mixture of metals of outstanding qualities, have several advantages over wood. Although using steel can be relatively costlier than wood, it reimburses for that cost since it can be reused. In other words, using steel may eventually be more economical than timber wood in the long run. The most commonly used steel formworks may contain steel, magnesium and aluminium.

Advantages of Steel formwork

  1. Steel formwork is robust and durable. As a result, it is capable of bearing loads on it
  2. Steel formwork is very easy to fix during construction more than wood
  3. It has an excellent shape on the surface that is smoother than using timber wood
  4. Steel in formwork can be used in great numbers without too many restrictions
  5. The use of steel is a more durable choice than wood formwork
  6. As earlier mentioned, using steel in the formwork is reusable and, therefore, can give a good value for the cost in the long run

Disadvantages of Steel formwork

  1. Using steel for formwork can be more expensive than using wood
  2. Steel in the formwork can lead to excessive weight and therefore can be more challenging to handle than wood
  3. Steel formwork is not easy to manipulate into a different structure. Consequently, it is highly limited in size and shape
  4. Plastic formwork

Formwork can also be made from plastic in a way that produces an impervious surface. This surface also gives a very smooth finish in the final structure and is valuable in private and commercial buildings. Plastic formworks can be reinforced or removed if there be a need. At the same time, the most critical use of plastic is that it is very light and more durable than steel and timber formwork.

Advantages of Plastic formwork

  1. Using plastic formwork produces a very light structure than other formwork types
  2. Plastic formwork is simple to cut and even nailed with the woodwork
  3. It can also be constructive in creating complex structures, shapes and some unique features
  4. It is also easy to remove any damage done to a plastic formwork, unlike other types of formwork

Disadvantages of Plastic formwork

  1. Plastic formwork is relatively costlier than the rest
  2. It cannot bear load as its strength may be small
  3. Plastic formwork is often prone to fire attacks and heat damage