A Guide On How To Fit Composite Decking Pedestals

Installing composite decking in your garden has many benefits. Composite materials are ideal for UK gardens because of their durability and properties that allow them to withstand UV rays during the summer and prolonged exposure to moisture during the winter.

Composite decking requires minimal upkeep, saving the homeowner time and money. You will be able to choose from a variety of colours and styles to get the perfect look.

Composite decking offers a long-lasting option that typically comes with a long warranty, and it is for this reason that installation is so important.

Poorly installed composite products won’t last as long and may invalidate warranties. This guide will take you through how to use composite decking pedestals to support your decking area securely.


What are Composite Decking Pedestals?

Decking riser pedestals allow you to install your subframe and joists at a set level above the ground to avoid moisture.

They also improve ventilation, allowing your subframe and area beneath the decking to air out sufficiently.

Adjustable composite decking pedestals allow the property owner to adjust the height of the deck and ensure a level surface to lay composite decking.

Decking pedestals can be fixed into the ground or left as what is known as a “floating installation”.

Whether you fix your decking pedestals is typically down to the surface you lay it on.

Fixed composite decking pedestals benefit from being laid on a level concrete or paved surface. Alternatively, they can be used on earth, tiles, or slabs.

The ground composite decking pedestals must be laid on a stable surface that will not shift.


Tools Needed to Fit Composite Decking Pedestals and Decking Boards

In order to install composite decking and properly fit your composite decking pedestals, certain tools and equipment will be needed.

Before carrying out a decking installation project, you must ensure you can do so safely. This includes working in well-ventilated areas when cutting or using solvents. Tools needed for this type of project include;

  • Pencil
  • String
  • Spirit Level
  • Tape Measure
  • Set Square
  • Jig Saw
  • Mitre Saw
  • Circular Saw
  • Hand Drill
  • PPE


A Guide on How To Fit Composite Decking Pedestals

Installing composite decking is essential to how well your decking performs, how long it lasts, and the product warranty.

The terms and conditions of your Ecoscape composite decking warranty require you to use the components and accessories provided and follow the supplier installation guide.

Creating a stable subframe is also an essential part of guaranteeing a long-lasting decking area. The following steps will help you to fit composite decking pedestals to keep your subframe clear of any moisture, lay a level deck, and enjoy your composite decking for as long as possible.

Step 1 – Preparing the Decking Area

The first part of using decking riser pedestals when installing composite decking is preparing the area and levelling the surface.

In some cases, the area may have pre-existing concrete or level land. If it does not, use a spirit level to ensure the area is levelled.

If you chose not to lay your decking area on concrete, laying a geotextile membrane will stop weeds from growing.

Step 2 – Plan your Decking and Support

Your next step will be to plan your decking height and layout. The height of the deck you choose will determine the riser pedestals you need to buy.

Riser pedestals are available in a range of sizes, and prices will vary depending on the height you choose.

The volume of pedestals needed will typically be advised by the supplier.

The material choice and decking size will determine the pedestals needed. The Ecoscape pedestal calculator will help you work out what is needed, and the team of experts is always on hand for further advice.

How your supports are spaced will be determined by the way your decking boards are aligned, and this should be decided before starting your project.

Step 3 – Installing the Composite Decking Pedestals

Laying out your composite decking pedestals at the recommended intervals will be the next step.

Depending on the surface you are laying the pedestals on, you may want to fix them to the surface at this point.

Fix composite decking pedestals with the fixing plugs provided.

Pedestal spacing will depend on the joists being installed and the thickness of the top boards.

When installing your decking pedestals, always include a slight incline to help with drainage and water runoff. The Ecoscape composite decking installation guide advises a gradient of around 1%.

The gradient should run with the boards and any grooves they may have to minimise the risk of water pooling and the detrimental effects this can have on decking.

Step 4 – Laying the Joists and Subframe

Depending on which way your composite deck boards are to be laid, your joist frame should be laid at a right angle to this.

When screwing the joists in place, you must take care of the adjustable mechanism of the pedestals.

You should use your spirit level to ensure the joists are level, but be sure to account for the 1% gradient.

Step 5 – Prepare your Joists for the Decking Boards

Pre-drill the joist for your starter clip by drilling in the centre at the end of your joist.

You should then screw the starter clip in place. Ensure the remaining clips are aligned by using string and install these too.

Step 6 – Install your Composite Decking Boards

Your first composite decking board should be slid into position using the clip and grooves on the side of the deck board.

You can then start to install the hidden T-clips by sliding them into the grooves of the first board and screwing them lightly into the joist.

You should not fully screw the T-clip into the joist. Next, you should add a hidden T-clip for each joist.

Install one locking clip to the centre of the composite board on the joist.

The locking clip allows a thermal expansion gap for the board. The next decking board can then be installed before following the process with the clips on the other side again.

Step 7 – Secure the Boards

When the second board has been placed, you can then fully secure the T-clips by screwing them down properly into the joist.

Use the T-clips and screw drill bit provided to ensure the boards and joists don’t suffer from any problems.

Step 8 – Installing the Boards End to End

When installing the decking boards end to end, you must leave a 2 mm to 3 mm gap to allow for thermal expansion.

Step 9 – Installing Breaker Boards

Breaker boards are deck boards that go across the design to create a break in the pattern.

This design is optional and can negate any gradient by stopping the flow of water.

Breaker boards can be installed by cutting off one side of the T-clip’s top section. This will allow the adjoining board to fit in tightly.

Breaker boards should also be fitted with double joists to provide adequate support.

Step 10 – Finishing the Decking

After installing the main boards, you will be able to create a clear edge by attaching a fascia trim.

The trim must be aligned with the edge of the board and fixed into the joists using the colour-coded screws provided.

The full Ecoscape composite decking installation guide is available for reference, or get in touch with the Ecoscape experts for further advice.


Buying Ecoscape Composite Decking Pedestals

Ecoscape has a great selection of paving and decking pedestals that are perfect for decking installation projects in the UK.

Ecoscape composite pedestals are manufactured in Italy and made from 100% recycled polypropylene.

1,500 tons of plastic is recycled, and the state-of-the-art electric injection press process used wastes no oil and has zero emissions.

Two Ecoscape pedestal options are available for consumers, with the King Pedestal providing a self-levelling head and support base. The Queen pedestal has an adjustable or fixed head.

Ecoscape pedestals can be used with steel, aluminium, plastic, or wood.

The grey and black pedestals are available in a range of sizes to suit all needs and have a waterproof membrane to protect them against the conditions.

The high-quality pedestals are designed for fast installation and have a 50-year design life and 15-year limited warranty.

If you want to learn more about the product sizes available, other product specifications and prices, visit the dedicated Ecoscape composite decking pedestal page.



How far should decking pedestals be placed apart?

Your pedestals should be positioned to support your joists and subframe. The distance your joists are set will be determined by the material you use.

Composite decking boards are typically heavier than wood, so joists need to be positioned closer together if you are using timber joists.

Always check with the manufacturer when you have more information about the decking material, subframe materials, and decking size, and you will be able to calculate how many pedestals are required and how far apart they should be set.

How do Ecoscape paving pedestals work?

You will always be provided with instructions so putting your Ecoscape paving pedestals together is easy.

To extend each pedestal to the required height, you simply enter the key and turn it to extend and easily adjust them.

Do decking pedestals replace joists and subframes?

No, your decking pedestal will not replace your decking joists but will securely hold them in position.

The benefit of using decking pedestals is they can be set at different levels to support a level deck, and they help to keep the decking boards and subframe away from the damp ground.

This will significantly improve the life expectancy and performance of timber frames. Decking subframes have to support the deck boards, garden furniture, and people, so they need to be strong.

Are decking pedestals environmentally friendly?

Ecoscape pedestals are made from recycled plastics, produce no waste oil, and boast zero emissions.

Not only does this mean the 100% recycled materials minimise the production of new plastics, but it also helps find a use for thousands of tons of waste plastic.

Why is composite a good material to use in UK gardens?

Composite is ideally suited for use in the UK for decking, fencing, cladding, and accessories because it will not rot, splinter, or attract pests like timber.

It is strong enough to provide a robust structure to support garden furniture, heavy decking, and people.

Composite require minimal maintenance and does not have to be weatherproofed and treated like traditional timber.

It is a long-lasting material that often comes with impressive warranties, and there is an excellent range of styles and colours of products.


Final Thoughts

Composite decking is a great option for UK gardens to provide a stylish, safe, and durable outside space for the whole family to enjoy.

Before you lay composite decking, it is essential that the subframe is high-quality and safe.

Waterproofing timber joists with joist tape can improve the life span and performance of a subframe.

Investing in high-quality and long-lasting composite decking can be a waste if the subframe doesn’t last as long.

Another excellent way to protect your subframe from prolonged exposure to moisture is by using decking pedestals.

Pedestals are a great way to keep the subframe off the damp ground and improve ventilation.

You will be able to easily adjust your pedestals to get your decking to the required height, and Ecoscape’s excellent composite options will provide quality performance for a long time.

Ecoscape offers two great pedestal options in a range of sizes and a variety of tools to help you carry out the job and enjoy a perfect finish.

Gary is the founder and CEO of Ecoscape UK. Gary graduated from Liverpool JM University in 2007 with a 2:1 in Economics. A passion for innovation, design and sustainability, Gary has put to market numerous wpc products/systems, some of which have UK and European registered designs. Outside of work Gary enjoys spending time with his family, the great outdoors and watching Manchester United.