Composite Decking Joists - All Sizes

Composite joists: 

Plastic joists are heavy duty and environmentally friendly decking supports that will last many years without needing treatment or developing rot. These plastic joists are made from recycled plastics known as Manticore Lumber and carry a 10 year warranty. While it doesn’t come with the same cachet as traditional wood, it's a composite material that will save you time and money on maintenance costs once it is properly installed. And remember that it will be hidden under your deck, so nobody will notice it. 

Plastic joists are very handy to work with. They can be used on uneven surfaces and will guarantee a moisture resistant framework while providing a strong supporting base for laying out your deck. It will also reduce the need for extensive work on the foundation. This is not to say that you shouldn’t pay attention to your foundation since the successful completion of your deck and its durability will rely on that structure.  

It is used mostly for decking substructures but can also be used as fence posts. The tools used for cutting and drilling plastic lumber are the same as if you were working with wood. However, it is possible to come across small pieces of metal, for this reason it is advised to avoid using diamond tipped blades and stick to tungsten carbide tipped drill bits and saw blades when working with this material.  

• Weatherproof
• Last a lifetime
• Maintenance free
• Moisture resistant
• Kid-friendly (no splinters)
• 10 Year Warranty
• No risk of splitting 

As with most decking projects, it is recommended to order a bit more than necessary. If you are short a couple of joists most manufacturers would be reluctant to deliver small quantities. Which could delay or put on hold the completion of the deck. And before you know it, the summer is over.

Please refer to the manufacturer’s instructions to calculate the correct amount. 

Discover Other Decking Products

Decking & Paving Riser Slope Corrector 0-5: Ensure a level surface for your decking or paving project with this adjustable slope corrector.

Coloured Decking Screws Range 35mm (Box of 100): Secure your decking with these colored screws, designed to blend seamlessly with your chosen decking material.

Hyperion Starter Fasteners (50 per box): Get your decking project started with these easy-to-use starter fasteners.

11-16mm Decking & Paving Riser: Easily adjust the height of your decking or paving project with this versatile riser.

Manticore Plastic Bearer 50mm x 50mm x 3.1m: Provide sturdy support for your decking with this durable plastic bearer.

10-40mm Decking & Paving Riser: Adjust the height of your project with this versatile decking and paving riser.

Hyperion Fasteners 6mm (100 per box): Secure your decking with these reliable 6mm fasteners.

12.5mm Support Pad: Enhance the stability of your decking or paving project with this support pad.

EnviroBuild Decking & Paving Risers (All Sizes): Find the perfect riser for your project from our comprehensive range of sizes.

Hyperion Fasteners 3mm (100 per box): Secure your decking with these reliable 3mm fasteners.

Decking & Paving Riser 10-30mm: Adjust the height of your decking or paving project with this versatile riser.

EnviroBuild 4-Way Joist Cradle: Simplify your decking installation with this 4-way joist cradle.

Paving Pedestal (All Sizes): Choose from our range of paving pedestal sizes to find the perfect solution for your project.

Protective Rubber Mat - 3mm x 200mm: This protective rubber mat is designed to prevent damage to your decking and paving projects, offering an extra layer of protection and durability.

Frequently Asked Questions

What is Manticore Lumber made of? Manticore Lumber is made from 100% recycled plastics, making it an eco-friendly alternative to traditional wood products.

How long does Manticore Lumber last? Our recycled plastic lumber is designed to be long-lasting and durable, with a 10-year limited warranty. It will not rot or require treatment, saving you time and money on maintenance.

Can Manticore Lumber be used in wet environments? Yes, Manticore Lumber is waterproof and can be used in areas subject to flooding or standing water, making it suitable for a wide range of environments.

What type of saw blade should I use when cutting Manticore Lumber? We recommend using tungsten carbide tipped saw blades for cutting our lumber profiles to ensure clean cuts and avoid damaging your tools.

Is Manticore Lumber recyclable? Yes, our products are not only made from 100% recycled plastic but are also fully recyclable, ensuring minimal environmental impact.

How many meters of Manticore Lumber should I order for my decking project? We recommend ordering approximately 4 meters of Manticore Lumber per 1m² of decking. This estimation may vary depending on the specific requirements of your project.

Delivery will always take place on a weekday (Mon - Fri).
For information on delivery costs and more view our delivery info page.