A NeoTimber® guide to everything you need to know about installing composite decking on concrete.
When laying composite decking over a hard surface like concrete, it can be tempting to cut corners and lay the decking directly onto the concrete to avoid the extra work of securing a proper composite decking subframe. A golden rule that you should live by, however, is to never install composite decking without a subframe. There are numerous reasons why this is a bad idea, and we outline these below.
Every composite decking solution requires a framework to ensure ventilation and structural integrity. What’s more, concrete is not always level, so securing your boards directly to it would mean that your deck would be all over the place. Another key reason to install a subframe is because, despite the long lifespan of NeoTimber® composite decking, excessive water build-up would deteriorate the product at a far faster rate. Therefore, a joist subframe of no less than 35mm is strongly advised.
You can install composite decking onto concrete, so long as you install a subframe for the composite deck boards to sit on first. This post will give you all the information you need to go about installing composite decking on concrete.
Why A Subframe Is So Important
A well-built subframe offers structural integrity to your composite deck, giving it the rigidity and support it needs to flex under changes in temperature and varying weight loads. Even giving support to the boards themselves, subframes ensure that there are no stress points or areas under greater strain. By directing force and pressure along its joists ,a quality subframe seamlessly spreads the load for optimal safety.
Most importantly, however, a subframe creates a vital space beneath the deck boards, where water can easily drain away and air can pass through. This airflow allows boards to dry much quicker, making for a safe, long-life deck.
Our Composite Joist Is The Ideal Fix For Composite Decking On Concrete
While timber is widely used as a subframe for standard wooden decking, issues can arise when placed directly onto a hard surface. This tends to manifest as rot caused by standing water. For those on a strict budget, NeoTimber® supplies no-maintenance joist tape to protect the upper surface of timber. However, if you’re not limited by your budget, we’d recommend our composite posts and joists above any other alternative. Let us tell you exactly why we believe composite is a far better option than traditional timber for building composite decking on concrete.
Longer life
Composite, as you may imagine, is a composition of more than one material. In our case, we make use of wood fibres and recycled plastic to create long-lasting, eco-friendly decking boards that are designed to synergise with our varied product range. As complimentary forces, the two marry strength with waterproofing and flexibility to create the resilient, strong, and weather-resistant ‘super wood’ that we call NeoTimber®.
NeoTimber’s custom-designed WPC (Wood Plastic Composite) joist is the perfect solution for fixing decking to a solid base. Designed specifically for fixing into concrete, it can be installed lengthways into the concrete itself to completely bypass the need for sinking posts.
Purpose Built For Drainage
You can install a WPC subframe without any fear of it warping or cracking. WPC Joists are hollow and have a drainage hole built-in to allow for water runoff. Assuming that your subframe may be sitting in water for an extended period of the year, WPC Composite Joists perform far better than their timber counterparts. Excellent at absorbing significantly less water, composite joists are capable of greatly reducing the warping effect typical joists could cause.
Easy To Install
Our NeoTimber® WPC Joists are easy to install, as you can drill straight through them and attach them to your concrete base. Simply drill through using a countersunk screw and fix at 500mm increments. You can then attach the deck to the joist board using our custom-engineered clip system – one that which fits down a guidance channel along the length of each joist.
Our WPC Joist is just one subframe product we offer. In fact, we have numerous widths of joist available, according to your requirements. Browse our full range of long-life subframe solutions here.
Raise Your Deck Higher (Without Posts), Using Our Custom-Built Pedestals
Adjustable between 18mm and 310mm, they can easily accommodate uneven surfaces, steps, and variations in ground level. Whether building your deck to reduce the step out of your patio door, re-level uneven steps, or introduce terracing to a sloping garden, our NeoTimber® adjustable pedestals can assist you. Custom-designed to fit perfectly with our small joists, they work together with your decking to provide the perfect subframe for raised decks on concrete bases.
Need Further Support or Advice?
If you’ve still got questions that have not been answered here, or you would like additional advice,
support or assistance then please give one of our friendly experts a call and we’ll be happy to help.
Just give us a call on 01530 382 180.