But those of us who are in the concreting business, can’t think of concrete slabs or structures without also imagining the formwork that would have been erected to create them.
Unlike other construction materials like metal and wood, concrete doesn’t have a form of its own – it just takes after its formwork. No wonder, then, that concreters give so much importance to setting up formwork systems that will support the poured concrete while it cures, and give it its desired shape, thickness, and surface finish.
Conventionally, boxing systems have been made of timber. It isn’t hard to see why, going by how readily timber is readily available in almost all parts of the world. Over time, though, plastic boxing systems have emerged as a viable replacement for timber formwork, and in this post, we’ll walk you through a quick comparison between the two.
Generally speaking, the industry assesses the quality of any formwork system on the basis of three parameters – safety, quality, and economy. We’ll use the same criteria for today’s timber vs. plastic formwork debate.
Which formwork system is safer – timber, or plastic? Well, both materials offer enough strength to safely support the weight of the poured concrete. But timber formwork systems require much heavier members for the same degree of strength that a lightweight plastic boxing is able to provide. Heavier members obviously require more effort for transportation from one place to another, and pose a greater safety hazard in case of a collapse or other accident.
Let’s look at another safety concern. The individual pieces in a timber formwork system are typically nailed to each other, and to wooden pegs that run around the structure. The task involves handling nail guns, drills, or other power tools, which by themselves may pose safety threats for workers. Plus, if you’ve ever worked with timber, you’ll be familiar with the nuisance that splinters become over time!
Plastic formwork brings none of these issues to the table. Individual boards are much lighter than their timber counterparts, and most plastic formwork systems have smart fixing details like Camlocks that just need to be twisted into place. By eliminating the hassles of carrying heavy members, using power tools, and dealing with splinters, plastic formwork systems lead to a safe and comfortable on-site experience. Of course, in the interest of safety, it is important to choose formwork boards that are adequately sized for the form and weight of the concrete slab.
As a natural product, timber is never free from minor faults and undulations; these can later get imprinted on the concrete surface. Concreters using timber formwork generally pair it with plywood facing to give the concrete a better finish. In contrast, the individual boards of plastic boxing systems have near- perfect surfaces straight out of the box, and impart the same quality to the concrete. Plust, the fixing mechanisms in plastic formwork systems ensure that individual boards are perfectly aligned and held together without any gaps, unlike timber boxing systems where boards are just nailed together and can create ridges or bumps in the concrete.
The most prominent quality difference between timber and plastic formwork systems, though, is seen in curved concrete slabs. Curves are extremely difficult to create using timber; concreters generally manage by placing several small sections along the curved profile. Plastic, on the other hand, opens up a while world of possibilities when it comes to casting curved concrete slabs. Plastic boxing boards are available in super-flexible variants that can be bent into practically any radius, as such, they create perfectly smooth curves in concrete, without most of the ridges that timber formwork produces.
And now we come to the biggest differentiating factor between timber and plastic formwork systems. A single batch of timber for a single concrete pour may not cost too much, but timber boxing systems have a short lifespan. On average, it’s impossible to reuse a timber boxing system more than a couple of times. Even a single pour may warp its members out of shape. Plus, timber is extremely vulnerable to weather conditions, and an unforeseen spell of rain between concrete pours can make exposed timber formwork unusable.
Plastic formwork systems are dramatically different. Durable enough to last for many years, they can be used over and over again without registering any changes to their form, finish, or strength. Here at Con-Form, we guarantee our plastic boxing boards for 7 years, and many of our clients have used them for 10 years or more. Just add up the costs of buying new timber boxing over a period of 7-10 years, and plastic formwork becomes the obvious choice.
But there’s more.
In the construction industry in general, and concreting in particular, project costs directly relate to time consumed. Timber boxing systems are notorious for the amount of time it takes to set them up, and then again to strip them down after the concrete has cured. Setting up and dismantling plastic formwork is a breeze in comparison. Our lightweight Con-Form boards, for instance, just need to be bent around steel pegs and attached with simple ‘twist-and-lock’ Camlocks. The process takes little to no time. and doesn’t need any specialized tools.
Stripping down a plastic formwork system is equally simple – the whole process goes backwards, and the individual boards are removed, washed, and stored until the next job.
Together, the durability and ease of use that plastic formwork offers, leaves timber formwork far behind. For professional concreters who undertake multiple concrete pours every year, plastic formwork is the obvious choice.
So here’s hoping that you enjoyed this little battle of the formwork systems! If you have any questions about plastic boxing in general, or our Con-Form boards in particular, we’ll be happy to answer them. Just leave us a message through our contact form below.
Guaranteed for 7 years!
Conventional timber formwork is vulnerable to weather conditions and tends to wrap after just a few hours. Con-Form boards, on the other hand, have a remarkable degree of reusability. In some cases, the system has even outlasted the guarantee of 7 years. Transitioning effortlessly from job to job, they help concreters cut down on the costs – and the hassle – of repeatedly buying timber boxing over a 7-year period.
Con-Form plastic formwork systems have been benefiting concreters, formworkers, and city councils Australia-wide for over 10 years now. Superflex, Flexible and Rigid Con-Form boards are available in easy-to-use starter kits, complete with Camlocks, pins, connectors, and accessories to get you started.