Staircase Shuttering with Plastic Boards: Step-by-Step Method for Waist Slabs and Risers

Staircase construction requires accurate measurements, proper support and reliable formwork. Unlike conventional slab shuttering, staircase formwork involves inclined surfaces, multiple riser panels, precise cutting and careful concrete placement.

The quality of the shuttering material directly affects the alignment, dimensions and surface finish of the finished staircase.

Traditional plywood is commonly used for staircase formwork. However, repeated exposure to moisture and concrete can cause swelling, edge damage and surface deterioration. This becomes particularly challenging when plywood is cut into narrow strips for staircase risers.

PAC® Shuttering Boards by Rajratan offer an alternative to conventional plywood. Manufactured using Plastic Aluminium Composite material, these boards are designed for waterproof performance, dimensional stability and repeated construction applications.

In this guide, we explain how to use PAC® boards for staircase waist slabs, side panels and risers, along with practical installation methods, product specifications and cost considerations.

What Is Staircase Shuttering?

Staircase shuttering is the temporary formwork arrangement used to hold freshly placed concrete in the required staircase shape until it gains sufficient strength.

A typical staircase formwork system consists of three main components:

1. Waist Slab Formwork

The inclined bottom surface of the staircase that supports the concrete and reinforcement during casting.

2. Riser Boards

Vertical panels installed between consecutive steps to maintain the required step height and prevent concrete from flowing out.

3. Side Formwork

Panels installed along the staircase edges to retain concrete and maintain the overall staircase profile.

Each component requires proper alignment, accurate measurements and adequate structural support.

Why Use PAC® Shuttering Boards for Staircase Formwork?

Staircase formwork involves several cutting and fixing operations. The material must maintain its shape while handling concrete pressure, moisture and repeated site operations.

PAC® Shuttering Boards are manufactured using industrial-grade plastics such as PP, LDPE and HDPE, combined with reinforcing materials including aluminium oxide and cross-linked polymers (XLP).

Their composite construction offers several advantages for suitable staircase formwork applications.

Waterproof Performance

PAC® boards resist water absorption, helping prevent moisture-related swelling during concrete casting.

Dimensional Stability

Their dense composite structure is designed to maintain consistent dimensions during repeated use.

Smooth Surface Finish

The smooth surface supports consistent concrete finishing and easier cleaning after de-shuttering.

Cutting Flexibility

PAC® boards can be cut into smaller panels for risers, side formwork and other construction applications.

Repeated-Use Potential

Different ECOPRIME grades offer approximately 30–40 and 60–100+ repetitions, depending on site handling and application.

Reduced Maintenance

Their non-porous surface helps simplify cleaning and reduces moisture-related deterioration.

PAC® ECOPRIME Standard vs Premium: Technical Specifications

Rajratan offers different PAC® Shuttering Board grades to suit varying construction requirements.

Specifications and repetition figures are indicative and depend on product grade, installation, support and handling.

For staircase formwork, the appropriate thickness should be selected according to the staircase design, concrete pressure, support spacing and engineering requirements.

Step-by-Step Guide to Staircase Shuttering Using PAC® Boards

Installing staircase shuttering requires careful planning to maintain the correct slope, tread depth and riser height.

Here is a practical installation sequence.

Step 1: Prepare the Waist Slab Bottom Support

The waist slab is the inclined structural concrete section that supports the staircase steps.

1. Install suitable steel props or scaffolding according to the approved formwork design.
2. Position wooden or steel runners along the staircase slope.
3. Check the required inclination using a level instrument.
4. Place suitable 12mm or 18mm PAC® boards over the supporting runners.
5. Secure the sheets using an appropriate fixing arrangement.

Ensure that the support structure is stable and capable of carrying the expected construction loads.

Step 2: Install the Side Formwork Panels

Side panels retain concrete along the open edges of the staircase.

1. Measure the staircase length and required slope.
2. Mark the staircase profile on the PAC® board.
3. Cut the board using a suitable circular saw or hand saw.
4. Position the side panel along the outer edge of the waist slab.
5. Secure it using appropriate supports, cleats and fasteners.

Accurate marking helps maintain the required staircase profile during concrete placement.

Step 3: Measure and Install the Riser Boards

Riser boards form the vertical faces of individual staircase steps.

1. Measure the required riser height and tread depth from the approved staircase drawing.
2. Cut PAC® boards into strips according to the required dimensions.
3. Position each strip vertically between the side panels.
4. Secure the riser panels using suitable supports and fixing arrangements.
5. Check the alignment and uniformity of every step.

Proper bracing is important to prevent movement or deformation during concrete placement.

Step 4: Check Reinforcement and Concrete Cover

Before concrete placement, complete the reinforcement arrangement.

1. Position reinforcement bars according to the structural drawings.
2. Use appropriate cover blocks or chairs to maintain the specified concrete cover.
3. Check reinforcement spacing and positioning.
4. Inspect all shuttering joints and support connections.
5. Ensure the formwork is clean and ready for casting.

Concrete cover requirements must follow the approved structural drawings rather than a fixed measurement for every staircase.

Step 5: Concrete Pouring and De-Shuttering

Once the formwork and reinforcement have been inspected and approved, concrete placement can begin.

1. Apply a suitable release agent if required.
2. Place concrete according to the approved concreting sequence.
3. Use a needle vibrator carefully to compact the concrete.
4. Avoid direct contact between the vibrator and shuttering panels.
5. Monitor the risers and side panels during concrete placement.
6. Remove the formwork only after the concrete has achieved the required strength and de-shuttering has been approved by the responsible engineer.

After removal, clean the PAC® boards and store them properly for subsequent applications.

Cost Comparison: Plywood vs PAC® Shuttering Boards

The initial purchase price is not the only factor to consider when selecting shuttering material.

For contractors, the cost per use provides a better understanding of the material’s long-term economics.

Consider the following indicative comparison:

Commercial Plywood

• Approximate price: ₹45 per sq. ft.
• Assumed repetitions: 5.
• Cost per use: ₹45 ÷ 5 = ₹9 per sq. ft.

PAC® ECOPRIME Standard

• Approximate price: ₹80 per sq. ft.
• Assumed repetitions: 40.
• Cost per use: ₹80 ÷ 40 = ₹2 per sq. ft.

PAC® ECOPRIME Premium

• Approximate price: ₹90 per sq. ft.
• Assumed repetitions: 60.
• Cost per use: ₹90 ÷ 60 = ₹1.50 per sq. ft.

These figures are indicative material-cost calculations and do not include labour, cleaning, transportation or other operating expenses.

Key Advantages of PAC® Plastic Centering Boards Over Plywood

1. Resistance to Water Absorption

Staircase formwork frequently comes into contact with wet concrete and moisture.

Unlike plywood, PAC® boards are designed to resist water absorption, helping prevent swelling and moisture-related deterioration.

2. Consistent Concrete Surface

A smooth formwork surface supports consistent concrete finishing.

Proper installation and joint sealing also help reduce surface irregularities and cement slurry leakage.

3. Suitable for Cutting Into Riser Strips

Staircase construction requires boards to be cut into different sizes and shapes.

PAC® boards can be cut into suitable strips for risers and side panels using appropriate cutting equipment.

4. Repeated Use Across Different Applications

Suitable PAC® boards can be reused for staircase, beam, column and slab formwork, provided the selected board specifications meet the requirements of each application.

5. 40% Buyback Credit Programme

Rajratan offers a 40% buyback credit programme on eligible used PAC® boards.

Customers can return eligible old boards and receive credit against new purchases, subject to the applicable programme conditions.

Cutting, Nailing and Maintenance Tips

Proper handling is important for achieving the expected reuse potential of PAC® Shuttering Boards.

Cutting: Use suitable circular saws fitted with carbide-tipped blades. Support the board properly during cutting to obtain clean edges.

Nailing: Use suitable nails or screws according to manufacturer recommendations. Avoid unnecessary damage near board edges.

Shuttering Oil: Apply a thin layer of compatible release agent when required for easier concrete removal.

Cleaning: Remove concrete residue using water and suitable cleaning tools. Follow manufacturer recommendations for hardened deposits.

Storage: Store sheets flat on a level, properly supported surface to avoid accidental bending and impact damage.

Ordering PAC® Shuttering Boards from Rajratan

Rajratan Industries Private Limited manufactures PAC® Shuttering Boards at its facility in Indore, Madhya Pradesh.

The ECOPRIME range is available in different grades and thicknesses for suitable construction applications.

Trial Orders

Contractors can enquire about trial orders of 5–10 sheets to evaluate the product under actual site conditions.

During the trial, assess:

• Cutting and trimming performance.
• Nail and screw holding behaviour.
• Concrete release.
• Surface finish.
• Cleaning requirements.
• Reuse performance.

Commercial and Dispatch Details

• Factory Location: Indore, Madhya Pradesh.
• Standard Sizes: 8 × 4 ft and other available sizes.
• Thickness Options: 12mm and 18mm.
• Trial Orders: 5–10 sheets, subject to availability.
• Payment Terms: 30% advance and 70% balance before dispatch.
• Transport: Available through established logistics partners.

40% Buyback Credit

Eligible used PAC® boards can be returned under Rajratan’s 40% buyback credit programme, subject to applicable conditions.

For current pricing, availability, trial orders and dealership enquiries, contact the Rajratan sales team.

Company: Rajratan Industries Private Limited

Address: 123–124, First Floor, Shastri Market, Opp. Gandhi Hall, Indore – 452007, Madhya Pradesh.

Phone: +91 9685727927 / +91 9685927927

Email: info@rajratan.in 

Frequently Asked Questions

1. Can PAC® Shuttering Boards be used for staircase construction?

Yes. Suitable PAC® boards can be used for staircase waist slab bottoms, riser panels and side formwork, provided the thickness and support arrangement meet the formwork requirements.

2. Which thickness is suitable for staircase shuttering?

Both 12mm and 18mm PAC® boards are available. The appropriate thickness depends on the structural design, concrete pressure, support spacing and formwork arrangement.

3. Can PAC® boards be cut and nailed like plywood?

Yes. PAC® boards can be cut and fixed using suitable woodworking tools and fasteners. Follow the manufacturer’s recommendations for cutting and fixing.

4. Do PAC® boards require shuttering oil?

PAC® boards have a non-porous surface that helps with concrete release. A compatible release agent may be applied when required by the application and desired concrete finish.

5. How many times can PAC® Shuttering Boards be reused?

ECOPRIME Standard offers approximately 30–40 repetitions, while ECOPRIME Premium offers approximately 60–100+ repetitions under suitable site conditions.

6. Can the same PAC® board be used for beam and column shuttering?

Yes. Suitable boards can be reused for beam and column formwork if their thickness, support and fixing arrangements meet the requirements of the respective application.

7. Does Rajratan offer a buyback facility?

Yes. Rajratan offers a 40% buyback credit programme on eligible returned PAC® boards, subject to applicable terms and conditions.

Conclusion

Staircase shuttering requires accurate measurements, proper support and reliable formwork materials to achieve consistent concrete dimensions and surface finish.

While plywood remains a commonly used option, repeated moisture exposure and cutting can affect its performance during staircase construction.

PAC® Shuttering Boards by Rajratan offer an alternative with waterproof performance, dimensional stability and high reuse potential.

With ECOPRIME Standard and Premium grades, contractors can select suitable boards for staircase waist slabs, risers and other construction formwork applications.

Explore PAC® Shuttering Boards by Rajratan for your next construction project.

https://shutteringboard.rajratan.in/