How to Install a Deck on Adjustable Pedestals? Step‑by‑Step Guide
Terrace pedestals have become a popular solution for composite, porcelain or slab decking. Why? Because they let you level an entire surface quickly and precisely—without screeds, concrete, or compromises. Here’s how to install a terrace using Liderwood pedestals and which accessories can help.
1. Why Choose Pedestals?
✔ Precision leveling – height adjustment allows you to achieve a perfectly flat surface even on highly uneven ground.
✔ Without screeds and gluing – especially useful on balconies, rooftops, and ventilated terraces.
✔ Quick installation and removal – if needed, you can easily remove or elevate a section of the deck.
✔ Insulation and ventilation – the air gap beneath the boards helps drain water and protects the substructure.
2. Installation Step by Step – From Base to Board
🔨 Step 1: Select the Right Pedestal
Choose the pedestal type that fits your structure:
ETL – for composite or wood joists
Available heights: 10–15 mm, 18–32 mm, 35–70 mm, 66–145 mm, 140–220 mm.
Ideal for composite decking: level terrain without screeding or concrete supports.
ETP – for porcelain or ceramic slabs
Wide stable base and head to support fixed joints. Adjustable up to 220 mm.
Perfect for ventilated slab terraces demanding precise alignment and drainage.
ETP FLEX – self‑leveling version
Height range: 25–230 mm, with automatic compensation for slopes up to 5 %.
Ideal for sloped or uneven substrates: FLEX auto‑adjusts, greatly reducing installation time.
📏 Step 2: Positioning the Pedestals
The layout of the pedestals depends on the material used:
Under Joists:
–– Place pedestals every 40 cm (center-to-center), parallel to the board direction.
– Adjust spacing depending on joist size and board type – heavier loads require tighter spacing.
– Leave expansion gaps near walls and edges – at least 5 mm.
Under Porcelain Slabs:
– Pedestal layout depends on tile size – typically one under each corner.
– For larger tiles (e.g. 60 × 60 cm), add a central support for better load distribution.
Tip: Always verify layout recommendations with the board/tile manufacturer. Proper spacing ensures safety and stability.
🔧 Step 3: Height Adjustment
Leveling the deck is a key stage:
– Use the adjustment key to precisely modify pedestal height without dismantling.
– You can adjust even after placing joists or slabs.
– With ETP FLEX, the pedestal automatically compensates for slope – saving time and avoiding errors.
🔩 Step 4: Assembling the Structure
Once the pedestals are positioned and levelled:
Installation of joists and composite boards:
– After laying the joists, install the boards according to the instructions – remember to maintain expansion gaps between the boards and at the edges.
Installing stoneware tiles:
– Lay the slabs directly onto ETP pedestals – ensure each tile is supported on at least four corners.
– Keep expansion joints (approx. 3–5 mm) to allow water drainage.
Installing composite decking boards:
– After fixing the joists, install the boards as per instructions – remember to maintain expansion gaps between boards and at the edges.
💡 Final tip:
At this stage, you can add shock-absorbing pads to reduce vibration and noise. Liderwood also offers levelling discs for steep slopes and the Solid key – essential for precision height adjustments.
➡️ For full installation guidelines, download our stoneware tile/composite deck manual or contact our support team.