Home / ANALYSIS / Materials / In need of support

[More Images]



However, there are certain issues with formwork that remains unsolved. Considering that the labour employed at the site is unskilled or semi-skilled, it becomes imperative that the engineering is in line level and the sizing of the formwork is uniform, says Deshani. The alignment is most important at the time of erection. Moreover, according to Bhosle of L&T, cost, successful repetition, weight, durability and adaptability are some of the common issues that linger with formwork. He should know. L&T and Peri are the two international brands that have created various types of formwork thus offering contractors a choice.

Construction uses many different types of formwork, for many different purposes. But the three main materials for creating formwork remain the same - timber formwork, engineered formwork (usually a metal frame) and stay-in-place formwork (usually pre-made concrete systems). These three alone can offer a variety of different ways to create slabs and structures.

Traditional slab formwork uses timber, masonry and carpentry to complete construction. The method works through tree trunks or other lumber supporting rows of stringers placed three to six feet or one to two meters apart with joints placed between the stringers. The only difference with the metal beam slab formwork is that steel is used instead of timber and metal props are used instead of supports.

This system is reusable and more methodical. The finish of the concrete is smoother and the formwork is easier to remove after the cement has cured. Modular slab formwork is created from pre-made timber modules or modules made from steel or aluminium.

These are usually produced in a factory offsite and added to construction once completed. In residential buildings, of up to seven storeys, contractors prefer to use wooden shuttering and wooden joists.

Advertisement

COMMENT Comment on this article

While formwork is an important aspect of construction, little attention is paid to it. Most construction companies consider it as a ‘form’ necessary before the concrete can be poured in.

Since the formwork also needs to be stripped or peeled off later, it is a temporary phase to the construction activity. However, according to Joshi of Peri India, a quantum shift in formwork was noticeable about 10 years ago. Formwork in casts is now available for up to 10 metres. Steel and aluminium, that can hold weight of 10 square metres, are also increasingly common.

This is a vast difference from the earlier formwork weights of 400-500 kgs. Compared to wood that requires large cross-sections and is not hollow, steel is available in tubes with a thinner framework and is lighter.

Safety is a crucial issue when building formworks. Since most formwork suppliers don’t have the supplier’s supervisor on site, the supervisor of the contractor needs to have the required mental bandwidth.

It is for this reason that Peri India ensures it provides a minimum of 30-days site supervisor to see the formwork through. Site safety is a most crucial aspect that contractors face. So what are contractors doing? Joshi of Peri India says that supervisors need to put in that extra effort to see that the formwork is being undertaken by a professional contractor who is experienced and certified in their knowledge and services.

Because formwork involves concrete which is heavily affected by a number of stresses, the incorrect use can be dangerous as the concrete may collapse. Formwork has, however, allowed people to build structures never before dreamed possible and paves the way for future construction. 

---