In the chaotic dance of a construction site—machines roaring, workers shouting, concrete mixers whirring—there lies an unsung hero: shuttering. It might look like just a set of panels and supports, but without it, the very skeleton of a building would collapse before it ever took shape.
In India, where we build amidst rain-soaked monsoons and scorching heat, the right choice of shuttering—whether it’s centering plywood, plastic shuttering ply, or recycled plastic boards—can make or break a project.
Let’s demystify shuttering, its purpose, types, removal timelines, and a few crucial site insights that could save your budget and your schedule.
What is shuttering work?
Shuttering, also called formwork, is a temporary mould used to hold freshly poured concrete until it gains sufficient strength to support itself. Think of it as the invisible backbone shaping every column, slab, and beam before they reveal their final form.
In traditional Indian construction, shuttering is typically made from centering plywood (sometimes spelled “centring ply“), steel plates, or timber. In recent years, modern materials like plastic shuttering sheets and recycled plastic construction materials have begun replacing conventional options due to their longer life and better performance.
What is the purpose of shuttering?
The primary purpose of shuttering is to:
- Support the concrete: Fresh concrete is fluid. Shuttering gives it the required shape and alignment.
- Achieve desired finish: Properly designed shuttering ensures a smooth, uniform surface finish with fewer defects.
- Maintain safety: Good shuttering reduces the risk of collapse and accidents during curing.
- Control dimensions: It allows precise control over beam depths, slab thickness, and column dimensions.
In a country like India, where every millimetre can impact costs and compliance, the role of shuttering cannot be overstated.
What is the process of shuttering?
The shuttering process involves multiple steps:
- Design and planning: Determine the load, shape, and area requiring formwork. Choose the type—whether steel, timber, centering plywood, or plastic shuttering plywood.
- Material selection: Many still use shuttering ply or centring plywood. However, recycled plastic sheets and plastic shuttering ply are becoming popular due to their durability and repeat-use potential.
- Fabrication and assembly: Cut and assemble the panels to form the mould. Supports and bracings are added to withstand concrete pressure.
- Application of release agent: This helps in easy removal of the shuttering without damaging the concrete surface.
- Concrete pouring and curing: Once concrete is poured, it’s left to harden and gain strength.
- Removal: After achieving required strength, the shuttering is carefully removed, revealing the final structure.
Types of shuttering
Shuttering comes in different types depending on material and application:
- Timber shuttering: Affordable and easy to fabricate, but not durable and absorbs water.
- Steel shuttering: Strong and reusable, but heavy and expensive.
- Centering plywood (or centring ply): Widely used due to cost-effectiveness and smoother finish than timber. But, centring ply price can fluctuate, and it deteriorates quickly after repeated use and exposure to water.
- Plastic shuttering ply and plastic shuttering plywood: Made from recycled plastic sheets, these are waterproof, strong, and can be reused up to 50–100 times if handled well.
- Aluminium shuttering: Lightweight and precise, mostly used for repetitive projects like mass housing. But comes with a high cost of maintenance.
- Recycled plastic boards and recycled plastic construction materials: A growing choice among sustainable builders. They divert plastic waste from landfills and reduce environmental impact while offering excellent performance.
Among these, plastic shuttering is rapidly gaining traction, especially in large-scale Indian projects, where consistent quality and reusability matter.
After how many days is the roof shuttering removed?
Timing the removal of roof shuttering is critical. Removing it too soon can lead to cracks or even collapse.
Typically, for slabs spanning up to 4.5 metres, shuttering can be removed after 14 days if standard M20 grade concrete is used.
However, if higher grades or rapid hardening cement is used, this period may shorten. The local weather, load, and site conditions also play a role. In hotter regions, concrete might set faster, but it also requires careful curing to prevent surface cracks.
When you use plastic shuttering or plastic shuttering plywood, de-shuttering becomes easier and leaves a smoother finish, reducing rework and plastering costs.
When to remove the shuttering of slab?
For slab soffits (the bottom support of the slab), general guidelines suggest:
- Props supporting slab can be removed after 7 days for slabs up to 4.5 m span.
- Props supporting slabs over 4.5 m span can be removed after 14 days.
- Beams and arches require even longer—usually around 21 days for larger spans.
The actual timeline can vary depending on the structural design and concrete strength gain.
Remember: plastic shuttering ply and recycled plastic sheets are easier to handle during removal due to their smooth surface and lower bonding with concrete.
How to calculate shuttering quantity?
Calculating shuttering quantity is essential for budgeting and material planning. Here’s a simplified approach:
- Identify surface area: Calculate the area of all surfaces in contact with concrete (sides, bottom, edges).
- Account for repetitions: If using centering plywood, you might need more sheets because they deteriorate faster. With plastic shuttering ply, one sheet can be reused many more times.
- Add wastage factor: Usually, a 5–10% additional quantity is considered to accommodate wastage, cuts, and damages.
For example, a slab of 100 m² area may need about 100 m² of shuttering. But if you’re using centering plywood that lasts only 10 repetitions, you’ll need to buy more compared to using plastic shuttering sheets that can last 50+ repetitions.
Why consider recycled plastic construction materials?
In India, cost and durability often drive decisions. But today, sustainability is no longer optional—it’s a necessity.
Recycled plastic boards and plastic shuttering sheets (like WoWBoards) are born from waste—turning discarded plastic into powerful construction allies.
Benefits include:
- Lower life-cycle cost: While initial price may be higher than centring ply price, the cost per use is drastically lower.
- Waterproof and weatherproof: No swelling or delamination in rain, unlike shuttering plywood.
- Consistent surface finish: Reduces plastering and rework.
- Supports green building goals: A step towards IGBC and GRIHA points.
- Reduced demand for virgin wood: Helps prevent deforestation and preserves natural resources.
Conclusion: A new era of shuttering for India
Shuttering may be temporary, but its impact is permanent—on structure quality, project timeline, labour safety, and even the environment.
The choice between traditional centering plywood and plastic shuttering plywood isn’t just a cost decision. It’s a decision about how we build our future—stronger, faster, and greener.
WoWBoards, made from recycled plastic sheets, offer an answer to all the challenges of conventional shuttering. They stand strong against rain, multiple reuses, and the harshness of Indian sites, all while keeping the planet in mind.
Ready to make your site future-ready?
Switch to plastic shuttering and leave behind the cycle of swelling, warping, and frequent replacements.
Talk to our team today to see how WoWBoards can transform your next project.