If there is one thing every contractor knows, it is this. A shuttering sheet that is too thin bends like a politician’s promise. A shuttering sheet that is too thick becomes unnecessarily heavy and expensive. And a shuttering sheet that is just right is the difference between a smooth slab and a rework nightmare.

Choosing the right thickness in plastic shuttering sheets is a bit like choosing the right cricket bat. Too light and you lose power. Too heavy and you lose speed. But choose well and everything connects beautifully.

Most contractors are used to working with construction plywood or construction ply. They look at the thickness stamped on the sheet and they already know what to expect. But plastic boards behave differently. A plastic plywood alternative does not react to moisture, does not swell, does not warp and does not lose strength in humidity. Which means you must select thickness based on engineering logic rather than plywood intuition.

So let us decode the thickness mystery like Tim Urban would. With humour, clarity and a desire to eliminate confusion from every site in India. And let us explain it with the storytelling simplicity of Piyush Pandey. Because choosing between 6 mm, 8 mm, 12 mm and 16 mm should feel less like a puzzle and more like common sense.

Before we begin, remember one thing. Plastic shuttering sheets do not behave like ply for shuttering. They behave like the future. Especially when they come from recycled plastic building materials crafted with precision, like the ones created by WoWMaterials under the brand name WoWBoards.

Let us dive in.

The First Rule: Do Not Compare Plastic With Plywood

Contractors often look at a plastic sheet and say
“12 mm plastic feels lighter than 12 mm plywood, so will it work the same?”

That is like comparing a racing cycle to a motorcycle based on weight.

Plastic and plywood are fundamentally different materials.

Plywood absorbs water.
Plastic does not.

Plywood loses strength when wet.
Plastic remains stable.

Plywood swells.
Plastic stays true to size.

Plywood delaminates.
Plastic is solid through and through.

This is why plastic shuttering sheets can be engineered for specific loads. The thickness you choose depends not on what plywood you used earlier but on what structural element you are casting.

Let us break down each thickness category, one by one.

6 mm Plastic Shuttering Sheets

Best For: Curved Work, Partitions, Lightweight Formwork, Cover Blocks, Void Formers**

Imagine you need material that bends with grace. Material that shapes itself around curved beams, round structures or architectural elements where flexibility is essential.

This is where 6 mm plastic sheets shine.
Think of them as the artists of the shuttering world.

When to choose 6 mm:

• Curved shuttering work
• Architectural moulds
• Light RCC elements
• Cover blocks
• Temporary partitions
• Areas with minimal load on the formwork

6 mm plastic ply board is flexible but strong. In curved applications, plywood often cracks or breaks. But plastic bends beautifully without losing integrity.

The advantage over plywood:

Plywood of this thickness becomes weak, absorbs moisture and breaks under screws.
Plastic stays flexible, waterproof and reusable for many cycles.

6 mm sheets are not recommended for heavy slab casting. But for detailing work they are perfect and cost effective.

8 mm Plastic Shuttering Sheets

Best For: Small Slabs, Side Shuttering, Additional Layering, Light RCC Components**

8 mm is like that reliable middle child. Not too flexible. Not too stiff. It works in various situations. Contractors often use 8 mm where plywood of similar thickness would not survive even one rainy day.

When to choose 8 mm:

• Side shuttering for beams
• Pedestal shuttering
• Lift wall detailing
• Light slab extensions
• Small formwork areas where weight is limited

8 mm sheets provide a good balance between strength and flexibility. They are ideal for small and medium load applications where plywood fails due to moisture or edge wear.

Why plywood fails here:

Thin plywood absorbs water and loses shape.
Wet plywood bends and changes alignment.
Repeated pours destroy plywood edges.

Plastic boards do not have these problems. They remain dimensionally stable and reusable for multiple cycles.

12 mm Plastic Shuttering Sheets

Best For: RCC Slabs, Regular Beams, Columns, Residential Construction**

Here we arrive at the hero thickness. The champion of general shuttering work. The thickness that contractors love because it handles almost everything.

12 mm plastic shuttering sheet is the closest comparison to the standard ply for shuttering used for slab work. Except plastic performs far better.

When to choose 12 mm:

• Slab shuttering
• Beam bottom shuttering
• Column formwork
• Residential and commercial RCC casting
• Any area with moderate formwork load

Builders in high humidity zones prefer 12 mm plastic boards because they do not swell even after heavy curing cycles.

Why plastic beats plywood here:

• No swelling even when stored in wet soil
• No delamination
• Smooth concrete finish every time
• Much longer life cycle
• Minimal maintenance required

Most contractors switching from plywood to plastic start with 12 mm first because they immediately see the performance difference.

12 mm WoWBoards are the workhorse of the formwork industry.

16 mm Plastic Shuttering Sheets

Best For: Heavy RCC Work, Higher Load Conditions, Industrial Construction, Deep Beams**

If 12 mm is the hero, 16 mm is the bodyguard. Thick, strong, uncompromising. This is for projects where the pressure of concrete is high and the formwork must stand like a wall.

When to choose 16 mm:

• Heavily loaded slabs
• Deep beams
• Industrial construction
• Retaining walls
• Large column formwork
• Projects requiring ultra rigid shuttering boards

16 mm plastic ply board is extremely strong. It does not deflect under concrete pressure when supported properly. It maintains alignment perfectly. For contractors who need stiffness and long term durability, this thickness is unmatched.

Why plywood cannot match it:

16 mm plywood still absorbs moisture.
It swells.
It becomes heavy.
It loses strength.
And it cannot be reused as many times as plastic.

16 mm plastic boards however remain consistent use after use.

The Secret Ingredient: Recycled Plastic Building Materials

One of the biggest advantages of plastic shuttering sheets today is sustainability.

WoWBoards are made using recycled plastic building materials. That means every board is a second life for plastic that would otherwise end up in landfills or oceans.

This gives contractors three major benefits:

• They get durable material
• They reduce waste
• They build responsibly

Plywood destroys forests.
Plastic shuttering saves trees.

This is not just better engineering. It is better citizenship.

How to Decide the Right Thickness on Site

Let us simplify the selection process.
Ask yourself three questions.

Question one: What load will the shuttering bear?

Higher load means thicker board.

Question two: Do I need flexibility or rigidity?

Curves need thin sheets.
Heavy beams need thick sheets.

Question three: What is my expected number of repetitions?

Plastic boards last far longer than plywood.
Thicker sheets offer even greater durability.

Practical Tips for Contractors

Tip one: Do not treat plastic like plywood

Plastic is stronger and lasts longer. Follow manufacturer spacing guidelines.

Tip two: Store vertically or on pallets

Plastic can withstand moisture but organised storage improves lifespan.

Tip three: Clean with plain water

No need for shuttering oil. Concrete does not stick to plastic.

Tip four: Use proper supports

This ensures zero sagging and perfect alignment.

Why WoWBoards Are the Smartest Choice for All Thicknesses

WoWMaterials has engineered plastic shuttering sheets that outperform plywood in every category.
Here is what contractors say about WoWBoards:

The finish stays smooth even after many uses.
The boards do not swell even after days of curing.
They handle load better.
They remain dimensionally stable.
They save money across the project lifecycle.
Workers find them easy to use.

WoWBoards are not just a plywood replacement. They are an upgrade in performance, quality and sustainability.

Conclusion: Choosing Thickness Is Choosing Efficiency

6 mm for curves and detailing.
8 mm for medium formwork.
12 mm for general RCC slabs and beams.
16 mm for heavy duty casting.

Once you understand the role of each thickness, shuttering becomes predictable, efficient and cost effective.

When the material is plastic instead of plywood, you get more strength, more durability and more control over your concrete finish.

And when the plastic shuttering sheets come from WoWMaterials, you get the best combination of engineering and economics.

Choose WoWBoards. Choose the Right Thickness. Build With Confidence.

If you want shuttering sheets that perform flawlessly and last for many repetitions, WoWBoards are the answer across all thicknesses.