Building a Terrace on Riser Pedestals

We are often asked what the advantages of decking pedestals are and why they are preferable to traditional glued/non-adjustable installation methods. There are many reasons! Adjustable decking pedestals offer numerous advantages.

Firstly, using pedestals simplifies layout and installation. JOUPLAST® PVC decking pedestals are designed to simplify the installation of decking, whether it is made of slabs, composite, wood, mixed materials or even low-height decking. Height-adjustable pedestals allow for quick installation without heavy earthworks.

Adjustable pedestals also offer great adaptability, flexibility and modularity, making it easy to change the configuration of the decking according to the changing tastes and needs of the owners over time. This modularity is particularly advantageous for temporary or evolving installations.

Made from recycled materials, JOUPLAST® pedestals are stable, durable and resistant to temperature variations and crushing. They are highly resistant to heavy loads and can support up to 1 tonne. Their design includes an ingenious screw system that prevents sagging over time. They also allow for effective drainage of rainwater.

Adjustable decking pedestals are practical and save money by reducing construction costs and minimising environmental impact through the use of recycled materials.

Another significant advantage is that the pedestals can be used on various types of ground, whether level, sloping or uneven. Our self-levelling pedestals allow you to compensate for or correct a slight slope, making it easier to install your decking on a variety of terrains. Whether you want to landscape your garden, balcony, pool area or even a space with a pergola, adjustable pedestals will be your allies in outdoor landscaping.

The space under the terrace on pedestals allows cables and pipes to pass through, facilitating the installation of electrical or plumbing systems without requiring additional work. This makes it easier for you to integrate lighting fixtures into your outdoor design project, for example.

In short, JOUPLAST® terrace pedestals offer a practical, economical and durable solution for terrace design, while meeting the requirements of professionals and DIY enthusiasts alike.

Before installing adjustable pedestals, it is important to stabilise the ground to ensure the durability of your wooden or slab terrace. Regardless of the installation context, the ground must be flat, levelled and free of any obstacles.

On concrete slabs, be sure to remove any contamination that could interfere with the installation and stable support of the pedestals.

On raw ground, it will be necessary to carry out minor earthworks in a few simple steps. First, you will need to excavate your ground in order to start with a flat base and ensure that the ground is properly levelled. The installation of a geotextile and the creation of a crushed stone foundation layer are then essential in order to be able to accommodate the adjustable pedestals in good conditions.

If installing on a waterproof surface, comply with DTU 43.1.

If installing with our Elevo® pedestal for metal posts, soil preparation is minimal and simply requires the installation of a geotextile for proper rainwater drainage.

The main constraint when installing on pedestals is the need for a minimum height under the threshold in order to install all the accessories required to build a terrace on pedestals.

Allow for a minimum height of 3 cm under the terrace slab.

NB: If the slab has a slope, use self-levelling pedestals, which will compensate for slopes of up to 5%. The same applies if the slab has uneven surfaces.

Jouplast® pedestals have a crush resistance test rating of over 1 tonne. However, the weight that a wooden or tiled terrace on pedestals can support does not depend solely on the strength of the pedestals.

Each type of flooring has its own strength. We therefore advise you to check with your timber supplier for more specific information.

More generally, if you plan to place a heavy item on your decking on pedestals, such as a spa, we recommend our PROFILDECK® solution (aluminium joists), which will allow for better weight distribution across the structure of the decking on adjustable pedestals.

Our terrace pedestals for slabs or wood are guaranteed for 10 years in accordance with our general terms and conditions of sale and our installation advice. Furthermore, we have never heard of pedestals deteriorating over time.

On another note, when walking on a terrace on pedestals, you may feel a slight sliding/clattering effect. To remedy this, we strongly recommend using our adhesive insulation squares on the slab plates, as well as our acoustic rubber pads on each pedestal head. These two products, made from recycled tyres, dampen movement on the terrace and reduce noise and resonance.

The advantage of a terrace on pedestal slabs is precisely that this installation requires no glue or screws. We can dismantle the terrace in no time at all and without impacting the ground. We do not need to fix the terrace pedestal slabs to the surface.

However, for wooden terraces, it is necessary to fix the joists to the pedestals so that the whole structure is secure. The decking boards must then be fixed to the joists using through screws or invisible fixings such as Fixego®.