What Are the Benefits of Using 100% Recycled Plastic Substructure?

Improving your garden gives you extra space to enjoy throughout the year. A well-designed composite decking area provides families with a space to relax, entertain, and play. It can also increase your house price.

Choosing the right materials for a decking project is essential as it will determine the overall finish and longevity of the deck.

You will also have to think about the decking substructure to ensure your decking, cladding, or fencing area is safe, secure, and long-lasting.

One option that is proving to be popular among our customers is our 100% recycled plastic substructure materials. We offer plastic fence posts, plastic joists, and plastic battens.

This article will explore the benefits of this environmentally friendly material, as well as its applications.



Are Plastic Joists As Strong As Wood?

Plastic joists offer great strength and can be every bit as solid as metal or wooden alternatives. Composite joists are not as strong as plastic lumber, and for structural purposes, we will always recommend plastic lumber over composite joists.

Plastic joists and posts also come with a range of benefits that make them more durable and long-lasting. Keep reading to find out more about the benefits of using recycled composite joists as an alternative to traditional wood joists.

Our composite joists 125x50mm can span up to 1500mm unsupported and can be used with our 100% recycled plastic fence posts, which measure 100x100mm. We also offer a 50x50mm joists, which can span up to 600mm. This joist tends to be used with our plastic decking supports but can also be used with the plastic fence posts – 100x100x3000mm.


Can You Screw Into Plastic Joists?

You can pre-drill and screw into plastic joists. This makes them easy to work with. Choosing a screw with corrosion resistance for outside use is advised.

Screws and T-Clips are provided with Ecoscape composite decking boards if you have chosen this material. This makes it easy to install on a secure plastic substructure.

Using the components and accessories provided by Ecoscape is essential. You must also follow the installation guide. Using a different screw system will invalidate the warranty.


Can You Screw Into composite Joists?

Composite joists are hollow and are not as easy to work with when compared to 100% solid plastic joists. If you want to unscrew a composite joist then the same hole cannot be reused. Composite joists generally have 5mm thick walls and a hollow chamber.



What Are The Advantages Of Using Plastic Joists And Battens?

Plastic joists and battens are an excellent alternative to traditional wood decking substructures. This is because they offer many excellent benefits.

It is always important to explore the benefits of different materials to ensure you get the best option for your needs. The advantages of using plastic joists and battens include:

Pest resistant

While homeowners in the UK typically won’t have to worry about termites, there are other wood-boring insects that people need to be wary of. If you are starting a decking project, this should be a consideration.

Wooden lumber is often cost-effective, easy to work with, and looks great, but it is in danger from the elements and pests. Some wood-boring insects found in the UK include:

  • Common Furniture Beetles
  • Wood Boring Weevils
  • Waney Edge Borers
  • Powder Post Beetles
  • Death-watch Beetles


Protecting timber can be time-consuming and costly. Composite joists and battens offer an excellent alternative, as pests will not attack them. This will allow you to enjoy the long-lasting material without having to spend time and money on protecting it.


Moisture resistant

Another excellent benefit of plastic lumber is its natural water resistance. This makes it perfect for outdoor applications.

Wooden timber requires regular treatments to protect it from water damage. The water can cause it to swell and contract, which can result in cracks.

Durable plastic offers homeowners an easy way to enjoy a moisture-resistant framework. This can improve the longevity of decking.


Rot resistant

Having a moisture-resistant framework also reduces the risk of rot. Prolonged exposure to moisture can affect wooden subframes.

Every effort should be made to ensure your decking is designed to allow airflow and drainage. However, it can still be exposed to moisture over the years.

It can be costly to replace rotten sections of your decking substructure. It can also weaken the structure if it goes unnoticed, which can be dangerous.


Easy maintenance

Choosing decking supports that don’t require much maintenance will help to save you time and money. Wooden decking supports need to be weather treated, protected from pests, and painted.

Using decking supports made from recycled plastics such as plastic fence posts means you won’t have these worries.

As well as saving the time and money required for decking support upkeep, it will also offer convenience.

Getting beneath your decking to maintain and protect your decking supports can be challenging. If there isn’t room for a crawl space, it may mean lifting your decking boards to reach them. Plastic fence supports are heavy duty and timber free, they can be concreted into the ground with peace of mind that they will never rot.


Long lasting

Ecoscape composite joists and plastic fence posts have a 25-year warranty. This makes them an excellent choice for people that want peace of mind and a long-lasting decking area.

It’s essential that decking substructures are designed to last at least as long as the other decking materials. This means you will enjoy better value for money and a high-quality, environmentally friendly decking supports.

It’s important that you adhere to the Ecoscape warranty terms and conditions. This includes using approved materials and following the installation guide.

Following the warranty terms and conditions will ensure your materials last as long as possible.



Where Can I Buy Plastic Decking Joists?

We have an extensive collection of plastic substructure materials. This includes plastic decking joists and plastic cladding battens that can be found on our site.

Using high-quality materials will allow you to build a strong and sturdy foundation. This can be done on flat, sloped, or uneven surfaces.

Our high-quality plastic joists are designed to prevent rotting and will reduce maintenance costs. They are designed to provide a strong supporting base for our collection of composite material decking boards.


The Environmental Benefits Of Using A Plastic Substructure, Plastic Joists, And Plastic Posts

Conscientious homeowners will want high-quality materials for their gardens. It’s also important for many to use environmentally friendly decking supports.

Ecoscape is dedicated to the production and supply of environmentally friendly products. This includes all of our plastic lumber and composite material.

Our environmentally friendly decking supports are made using 100% recycled plastic. The material is also recyclable so in the future the plastic substructure can be used again.

In 2021, Ecoscape was responsible for recycling almost 4,500 tons of plastic waste.

We use 100% recycled HDPE (high-density polyethylene) in Ecoscape products. We also use sustainable dyes and bonding agents.

This all contributes towards reducing the number of ocean plastics and plastic that ends up in landfills. It also works towards reducing the carbon footprint of Ecoscape.

Ecoscape uses 100% recycled plastics for our products. They say recycled plastics are also recyclable meaning that any off-cuts or older materials don’t need to go to landfills.



How To Build A Decking Substructure Using Plastic Posts And Plastic Joists

Ecoscape ensures you are able to safely use the materials you buy by providing a detailed installation guide.

It’s essential that this installation guide is followed. Failure to properly install the materials can invalidate the warranty. It will also compromise the safety of the decking substructure and how long it lasts.


The Tools For Decking Substructure Installation

Using the right tools to install a plastic decking substructure is important. The tools required to install your substructure and decking area include:

  • Jig Saw
  • Mitre Saw
  • Hand Drill
  • 3mm Drill Bits
  • Countersink Drill Bits
  • Pencil
  • Tape Measure
  • Spirit Level
  • Set Square
  • String-Line
  • Protective Eye Wear
  • Personal Protection Equipment (PPE)


It’s advised to avoid using diamond-tipped blades when working with plastic lumber. Instead, tungsten carbide-tipped saw blades and drill bits are better suited.


Plastic decking substructure installation preparation

When installing a substructure using plastic joists, you should fix them to concrete sunk plastic fence posts.

Ecoscape offers an excellent 100mm x 100mm post made from 100% recycled plastic. The 3000mm long, heavy duty off-duty posts are designed for use in concrete and are available in dark brown or black.

Our plastic posts offer low-maintenance and weather-resistant qualities. They help to protect homeowners from splinters and rot. The 25-year warranty matches that of the joists and battens.

Ecoscape plastic joists support the following spans:

  • 50 x 50 x 2400mm Plastic Joists – Span 600mm – Centres 400mm
  • 125 x 50 x 3000mm Plastic Joists – Span 1500mm – Centres 400mm


Pre-drilling profiles before bolting the joists together are essential. Allowing a variation on either side of 1.5% allows for temperature fluctuations. Expansion gaps must be allowed during installation. Because of this, press-fitting is not an option.

The area being covered by the decking area must also be prepared. This includes removing the top layer of turf and laying gravel or scree to help with drainage. A slope of around 4mm per metre should be incorporated into the design.

If you plan to use composite materials for your decking boards, you must allow a space of at least 75mm from the ground.



Decking substructure installation

The plastic support posts must be cemented at a minimum depth of 500mm. They should create a grid layout at intervals of 1,500mm for residential properties. 1,000mm intervals are advised for commercial properties.

As the posts are set in the concrete, it’s important that they remain upright and the tops are level.

You can then lay out your cross-bearers to create a structure to support the joists. 125mm gaps must be left when attaching the bearers to allow for the joist’s thickness.

Bearers must have an expansion gap of 10mm. Double bearers should be used to support joins in the joists.

Pre-drill the posts and use single-thread screws at the intersections between the post and bearer. The joists can then be laid out at the recommended spacing.

The plastic joist frames can then be attached to the posts by bolts. The bolt holes should be oversized by 3mm which allows for thermal expansion.

The joist should be supported in at least 3 places, and a 10mm gap must be left where joists meet the cross beams. The ends of deck boards should not share a single joist at the butt joint.

Double joists should be present where two decking boards meet to provide sufficient support.


Where Can Plastic Joists And Battens Be Used?

Plastic joists and timber battens are versatile materials that are perfect for a number of applications in your garden.

The main use is to provide a strong structure to support a decking project. The durable material is low-maintenance and long-lasting. You won’t need to worry about your decking substructure warping in extreme temperatures with our plastic range.

If you are planning to carry out extensive work in your garden, plastic joists, battens, and posts can be used for a variety of projects.

Garden and home projects that can benefit from recycled plastic lumber include:



Installing a new plastic fence can help to provide homeowners with additional security and privacy. A well-built fence can also improve the aesthetic, as well as block noise from nearby roads, schools, or workplaces.

Here at Ecoscape, we offer a great range of composite fencing materials. They are long-lasting, offer soundproofing, and are available in a range of colours.

Our plastic joists, fence posts,, and battens can also be used for fencing projects. Using plastic lumber for fence posts provides great stability and durability.

Plastic lumber is perfect for outside use because it is water-repellent and won’t rot. It is also impervious to pests.

Battens can be used in fencing to provide additional privacy for people that don’t want anyone to see into their garden. This is also great for security as passers-by won’t be able to look into gardens to check for weaknesses or opportunities.



External cladding is used for protective and aesthetic purposes. It is also used to improve your home’s insulation, making it a worthwhile addition.

Properly installed joists are required for cladding projects. Ecoscape’s great range of plastic joists and cladding battens is perfect for the job.

The installation of plastic battens provides the perfect foundation for our composite cladding range. This further protects the exterior wall and ensures a long-lasting solution.


Plastic Lumber Specifications

Our collection of plastic lumber products is available in a range of sizes. This makes it easier for our valued customers to find the perfect product.

Our product range includes:

Composite Joists

  • 125 x 50 x 3000mm / 5 x 2 x 118 inches
  • 50 x 50 x 2400mm / 2 x 2 x 95 inches


Plastic Fence Posts

  • 100 x 100 x 3000mm / 4 x 4 x 118 inches



  • 50 x 25 x 3000mm / 2 x 1 x 118 inches
  • 100 x 20 x 2800mm / 4 x 0.8 x 110 inches




Are recycled plastic materials difficult to cut?

Cutting your materials to the correct size is essential. Using the correct tools to do this will minimise the risk of damage.

Tungsten carbide saw blades are recommended for cutting plastic lumber. It is possible that diamond tipped blades or small pieces of metal can find their way into plastic timber so using diamond-tipped blades is not advised.


Is plastic lumber expensive?

Plastic lumber is typically more expensive than real wood, but it can be more cost-effective in the long term. This is because there are no maintenance costs associated with the material.

It is also a much cheaper alternative to aluminium options and is easier to work with.


Will thermal expansion affect plastic lumber?

Yes, in extreme temperatures, plastic lumber will expand and contract. This can cause issues if it has not been taken into account during the installation process.

Leaving small gaps to account for expansion will minimise the risk of materials pushing against one another and warping.


Is plastic lumber easy to clean?

Plastic lumber is easy to clean. All you need is mild soap and warm water to wipe down the surface.

You should avoid abrasive cleaning tools and harsh chemicals when cleaning plastic timber.


Can plastic joists be used with pedestal systems?

Ecoscape decking pedestals are compatible with the plastic joist options. This makes it easy for people to install secure deck substructures.

Simply space out the pedestals at set distances and secure the joists. Pedestals can be adjusted to ensure they are level.



Final Thoughts

Our collection of plastic lumber products is perfect for garden projects. This is because of their great durability and versatility.

This durable material is perfect for building decking projects on uneven surfaces. Properly installed substructures will last a long time, and our joists, battens, and posts come with a 25-year warranty.

Treating and maintaining traditional wood timber is expensive and a lot of hassle. With our recycled plastic lumber, you don’t need to worry about maintenance.

You’ll also receive an environmentally friendly product that delivers great performance.

Explore our extensive range of plastic and composite products for all garden projects. Our extensive range of sizes, colours, and styles ensures everyone is catered for.

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.