Frequently Asked Questions

ouplast® breakable flat shims are designed for low-height adjustments.

Available in various thicknesses (2, 3, and 5 mm), they are ideal for leveling carpentry elements, compensating for irregularities, and ensuring proper spacing between materials.

Their divisible design offers great flexibility and adapts to the specific requirements of each project. They provide excellent stability and high compressive strength.

All our slabs can withstand weights that are perfectly reasonable for traffic:

• Alveplac® and Greenplac® can withstand up to 600T/m² filled with gravel or grass.
• Urbangravel® can withstand up to 800T/m² filled with gravel.
• The entire URBANIT® range, designed for more intensive vehicle traffic, can withstand up to 1000T/m² filled with grass, gravel or paving stones.

The mechanical strength of our slabs is the fundamental criterion in our development process in order to guarantee soil stability.

Our self-levelling pedestals can be installed on uneven ground, as long as the ground has been properly prepared. They also work on existing concrete slabs, and it is very convenient to be able to install them against an existing structure without any difficulty.

Low-profile pedestals can only be used on flat, level floors with no difference in level exceeding 1.5%. In addition, pedestals can only be installed on stabilised ground or existing concrete slabs.

Is your floor uneven? Don’t panic, you can fix this by following a few simple floor preparation steps. For more information, please refer to our installation advice documents.

Our paver or timber decking pedestals come with a 10-year guarantee, based on our terms and conditions of sale and our installation guidelines. Furthermore, we have never been aware of any deterioration in the pedestals over time.

On another note, when walking on a raised patio, you may feel a slight sliding or clicking sensation. To remedy this, we strongly recommend using our isolation pad, to be placed on the paving slabs, as well as our rubber cushions, to be placed on each pedestal head. These two products, made from recycled tyres, cushion movement on the patio and reduce noise and resonance.

To find out more, please take a look at our products: the isolation pad and the rubber cushion.

Before laying the slabs or wooden boards, it is important to ensure that your pedestals are securely fixed in place. Here are the steps to follow to secure them, regardless of the type of pedestal chosen:

Start by marking out the area. This will determine the exact location and dimensions of your patio. Then, prepare the ground.

On bare ground

1. Clean the area and remove any vegetation or debris.
2. Remove approximately 15 cm of topsoil. For slightly sloping ground (up to 5%), self-levelling pedestals can compensate for this incline.
3. Lay a geotextile membrane: this prevents weeds from growing back and limits rising damp. Cut it to the dimensions of the area to be covered and ensure there is sufficient overlap at the edges.
4. Create a base layer using 0/31 crushed stone.
5. Compact the surface using a vibrating plate.

A small exception applies to the 8 x 20 mm terrace pedestal: we recommend creating a draining base layer made of 30/60 or 40/80 crushed stone instead of 0/31 crushed stone. Then, finish with a thin layer of gravel to achieve a perfectly level surface. Finally, compact it with a vibrating plate.

On a concrete slab

1. Remove any debris (rubble, stones, etc.) that could hinder the installation or prevent the pedestals from staying firmly in place.
2. Check the available heights at the thresholds. This will help you choose the correct size of pedestals for your project.

Depending on the nature of the ground, a drainage base can be laid beforehand using a layer of 30/60 or 40/80 aggregate.

If the resulting surface still has some imperfections, it is recommended to create a bedding layer using quarry sand or crushed sand of type 0/4. This will facilitate the installation of low-profile pedestals. It is recommended to use a vibrating plate between each layer.

On uneven or sloping ground, it is not necessary to level the surface if you are subsequently using self-levelling pedestals.

Geotextile separates the different sub-layers of soil. For example, it separates sand and gravel. Geotextile also prevents weeds from growing in the gaps between the gravel.

The surface on which the paved patio will be built must be prepared before work can begin. Unprepared ground (e.g. unprepared soil) may change over time and can be subject to movement. Depending on the weight it will subjected to and the local climate (dry periods, heavy rainfall, etc.). For these reasons, it is important to stabilise the ground beneath the patio to ensure long-term stability of your project.

Jouplast 5 mm flat packers are designed to meet minimal packing requirements across a broad range of joinery and construction projects. Their 5 mm thickness corrects any irregularities in the underlying structure and provides stable, durable packing. They also guarantee excellent ventilation of timber decking structures, in accordance with the recommendations of DTU 51.4. Very strong, they can support heavy loads with no deflection.

Aluminium joists offer many advantages that wood does not. Aluminium has the following performance characteristics:

First and foremost: durability over time. Aluminium structures are rot-proof, which makes them much more durable than wood.

Our aluminium joists are treated against corrosion to withstand humidity and even the salty climate found near swimming pools or the seaside. This is not the case with wood.

Jouplast® aluminium decking joists are much lighter to transport and install. Each joist measures 2.4 m and weighs 2.32 kg. In general, a pine joist of the same dimensions weighs between 3.5 and 4 kg, depending on the type of wood and its moisture content. This means that when handling joists on a building site, wooden joists are heavier than aluminium joists. This poses musculoskeletal risks that should not be overlooked.

If you are looking for a durable, easy-to-maintain solution that offers great stability, aluminium joists are an excellent choice. However, if you prefer a more economical option and appreciate the natural aesthetics of wood for decking boards, wooden decking joists may be more suitable, provided you are prepared to carry out regular maintenance.

The Cleman® self-levelling 80/130 patio pedestal can be used on stabilised uneven ground or an existing concrete slab. Its three-stage adjustment system provides quick and accurate height setting. It must be positioned under the paving in accordance with the recommendations of the paving manufacturer, with at least one pedestal at each corner of each paving slab.

The Cleman® patio pedestal must be installed on stabilised ground or an existing concrete slab. It must be positioned under the paving in accordance with the recommendations of the paving manufacturer, with at least one pedestal at each corner of each paving slab. Its progressive adjustment system allows height adjustment before, during and after installation, ensuring optimum alignment and a perfect finished installation.

The Profildeck® anti-condensation tape is designed to limit the formation of condensation as a result of variations in temperature and to limit damp rising between joists and decking boards. This reduces the risk of timber deterioration and protects the decking structure. Self-adhesive and untearable, it ensures installation durability and effectiveness.

The Jouplast® rubber joist support pad is designed to make decking construction easier by supporting and cushioning the joists. Made from recycled tyre rubber, it provides effective isolation against damp and ensures good ventilation of the structure, reducing the risk of the timber structure rotting and deteriorating. It also improves comfort in use by dampening transmitted impact noise.

Yes, the 3mm terrace spacer is a multipurpose accessory. It can be used with different types of terrace surface, including ceramic paving, tiles and even timber decking boards. Ensures precise and consistent spacing, regardless of the material used.

The Cleman® hexagonal bit is used to set the precise height of Cleman® riser pedestals during installation and after completion of the project. A simple and effective way to precisely set riser pedestal heights.

MODULESCA® 20 cm step modules can be used to create straight or curving flights of garden steps. Depending on the slope of the terrain, tread dimensions and gradients may vary. For example the maximum terrain gradient for a straight flight of steps is 36° (70%). For curving steps, the external radius of a 20 cm module and a single step is 1,960 mm, with a maximum angle of rotation of 10°.

Our paving stone stabiliser is suitable for all concrete paving stones measuring 15 x 15 cm and 6 cm high. We also allow stone or sandstone paving stones, even though they are less common because they are more expensive.

We recommend choosing paving stones with smooth sides without protrusions. The paving stones must not be aged. Often when they are aged, they have been tapped and have irregularities. This makes them unique and attractive but uneven. Using this type of paving stone would make installation and traffic on our paving stone stabilisers unstable.

The manufacturing tolerance according to standard NF EN 1338 is +/-3mm on the 150 mm side.

This type of paving stone is easily found in DIY superstores or building material suppliers.

The height of your deck will depend on the available space (between the ground and your glass door thresholds, for example).

To calculate the height of the pedestals you will need, it is important to take into account: the thickness of your wooden decking boards, the thickness of the joists (or joists in the case of cross joisting), the thickness of the invisible fasteners if you decide to use Fixego, for example, but also the thickness of the joist protection strip.

Then simply subtract all these heights from your reservation height to find out how much space you have left and choose the right pedestal height. Are the pedestals still too high? You can lay your decking on wedges. The most important thing is not to lay your joists directly on the ground, as they could get damaged very quickly.

We now offer a wide range to meet all your needs, from 8 mm to 230 mm and more, by adding extensions to your Jouplast® PVC pedestals.

Yes, it is essential to prepare the surface on which the pedestals will be installed. An unprepared surface (e.g. laying directly on soil or grass) may change over time and shift depending on the weight it bears and weather conditions (drought, heavy rain, etc.). This is why you must stabilise the ground to ensure the long-term durability of your project.