Calculation of pedestals for wood and slab terraces
What spacing between pedestals? What center-to-center distance between joists? How many pedestals per m²?
Terrace pedestals, whether fixed or adjustable, allow for the installation of wood and slab terraces. This installation method is simple and quick to set up, provided certain rules are followed. Depending on whether your terrace is made of wood or slabs, you will need to take several factors into account to determine the number of pedestals required.
Slab terrace installation
| Slab terrace on pedestals | Terrace surface area | |||||||
|---|---|---|---|---|---|---|---|---|
| Slab dimension | Installation type | 20 m² | 40 m² | 60 m² | 80 m² | 100 m² | 200 m² | 1000 m² |
| 40 x 40 | 1 pedestal / corner | 7.7 | 7.2 | 6.9 | 6.8 | 6.8 | 6.6 | 6.5 |
| 45 x 45 | 1 pedestal / corner | 7.7 | 7.2 | 6.9 | 6.8 | 6.8 | 6.6 | 6.5 |
| 50 x 50 | 1 pedestal / corner | 5 | 4.7 | 4.6 | 4.5 | 4.4 | 4.3 | 4.1 |
| 60 x 60 | 1 pedestal / corner | 4 | 3.6 | 3.3 | 3.4 | 3.2 | 3.2 | 2.9 |
| 1 pedestal / corner + 1 central pedestal | 7.2 | 6.6 | 6.4 | 6.4 | 6.1 | 6 | 5.7 | |
| 75 x 75 | 1 pedestal / corner | 2.8 | 2.6 | 2.3 | 2.3 | 2.3 | 2.1 | 1.9 |
| 1 pedestal / corner + 1 central pedestal | 4.9 | 4.7 | 4.2 | 4.2 | 4.2 | 4 | 3.8 | |
| 80 x 80 | 1 pedestal / corner | 2.4 | 2.1 | 2.1 | 2 | 2 | 1.8 | 1.7 |
| 1 pedestal / corner + 1 central pedestal | 4.2 | 3.8 | 3.7 | 3.7 | 3.7 | 3.4 | 3.3 | |
| 90 x 90 | 1 pedestal / corner | 2.1 | 2 | 1.7 | 1.7 | 1.7 | 1.6 | 1.3 |
| 1 pedestal / corner + 1 central pedestal | 3.6 | 3.5 | 3.1 | 3.1 | 3 | 2.9 | 2.6 | |
| 45 x 90 | 1 pedestal / corner + 1 pedestal along long side | 6.5 | 6 | 6 | 5.7 | 5.8 | 5.5 | 5.1 |
What spacing between pedestals?
The spacing between your pedestals will be determined by the size of the slabs you have chosen. Indeed, if your slabs measure 60x60 cm, then the spacing between the pedestals will be 60 cm. Thus, the larger your tiles, the fewer pedestals you will need. Note that for slabs starting from 60 x 60 cm, feel free to add a central pedestal to stabilize and strengthen your terrace. For rectangular slabs, starting from 120 cm in width, plan for two central pedestals per slab.
How many pedestals per m² for a slab terrace on pedestals?
To define the number of pedestals needed for your project, you must first determine two elements: the terrace surface area in m² and the size of your tiles. Find all the necessary information in the table above.
To help you with installing your slab terrace, check out our dedicated article!
Fixed Pedestals
Practical for renovation work on an existing terrace or for low-height installations. It is also used for rooftop terraces.
Adjustable Pavers: from 25 to 385 mm
Adjustable pedestals allow millimeter-level adjustments and the installation of elevated terraces. Combine multiple pedestal sizes.
Self-Leveling Pedestals: from 50 to 285 mm
Self-leveling pedestals allow installation on uneven or non-solid ground without major construction work. You can also create or compensate for up to 15% slope.
Wooden deck installation
| Wooden deck on pedestals | Deck area | |||||||
|---|---|---|---|---|---|---|---|---|
| Type of board | Installation type | 20 m² | 40 m² | 60 m² | 80 m² | 100 m² | 200 m² | 1000 m² |
| Wood board | joist spacing 50 cm: 1 pedestal / 70 cm | 4.1 | 3.9 | 3.7 | 3.5 | 3.4 | 3.2 | 3 |
| joist spacing 50 cm: 1 pedestal / 50 cm | 5 | 4.7 | 4.6 | 4.5 | 4.4 | 4.3 | 4.1 | |
| Composite board | joist spacing 50 cm: 1 pedestal / 70 cm | 4.6 | 4.6 | 4.4 | 4.2 | 4.1 | 3.9 | 3.8 |
| joist spacing 50 cm: 1 pedestal / 50 cm | 6.1 | 5.8 | 5.6 | 5.5 | 5.5 | 5.3 | 5.2 | |
Spacing between pedestals?
The spacing between your pedestals will depend on the type of wood chosen. For exotic wood, the spacing is 40 cm. Place pedestals under your exotic joists every 70 cm. For softwood decks, the spacing is 50 cm. As with exotic wood, your joists should be supported every 70 cm.
How many pedestals per m² for a wooden deck on pedestals?
To determine the number of pedestals required for your project, you first need to define two things: the type of wood used and the deck area in m². Find all necessary information in the table above.
For more information on installing a wooden deck, see our dedicated article!
Fixed pedestals
Practical for renovating an existing deck or for low-height installation. Also suitable for rooftop terraces.
Adjustable wood pedestals: 25 to 358 mm
Adjustable pedestals allow millimeter-precise adjustment and the installation of raised decks. Combine different pedestal sizes.
Self-leveling wood pedestals: 50 to 285 mm
Self-leveling pedestals allow installation on uneven or unstable ground without major construction work. You can also create or compensate for up to 15% slope.
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