VitaroUNO INDUSTRIALInstallation guide
Adjustable Pedestal Installation Guide: Step-by-Step
Adjustable pedestals turn a flat (or sloped) roof slab into a level, ventilated raised floor — for decking, porcelain paving or a tiled terrace — without wet trades, mortar or fixings into the structure. If you want to know how to install deck pedestals on a terrace, rooftop or balcony, this guide walks through a complete install for both deck and paver builds. If you haven't sized the system yet, start with how to choose the right pedestal.
1. Tools & parts you'll need
- Pedestals sized to your finished height (see Vitaro series), plus extenders if needed.
- Rubber shims / protection mat for the membrane.
- For decks: timber or aluminium joists and deck boards.
- For paving: 600×600 mm (or similar) pavers / porcelain tiles.
- Tape measure, string line, spirit level, rubber mallet, utility knife.
- Optional: spacer tabs / ledge clips to keep even joints, and edge restraint clips.
2. Plan the pedestal grid
Mark a square grid on the slab. A typical spacing is 500–600 mm between pedestals:
- Decking: run joists at ~500 mm centres; one pedestal under each joist crossing.
- Paving: place a pedestal under each corner of every 600×600 mm tile, so each tile rests on 4 supports.
Tighter spacing is required for heavier stone or higher loads. Confirm spacing against the load table at your exact finished height before ordering.
3. Protect the substrate / membrane
Pedestals protect the waterproofing by spreading load through a wide base — but take two precautions:
- Lay a protection board or rubber mat (or rubber shim under each base) on sensitive membranes.
- Never drag pedestals across the membrane — carry and place them.
- Keep the drainage falls clear: pedestals are open-sided so water drains between them; don't block the perimeter outlets.
4. Set the height & head type
Measure from the slab to your target finished floor level. Then:
- Thread the pedestal body to roughly the right height, then fine-tune with the adjuster ring.
- Use a fixed head on flat slabs; use the self-leveling head (±5°) on sloped or uneven roofs so the surface stays level.
- Add a 100 mm or 150 mm extender if you exceed the base range (F 20–185 mm, B 20–260 mm, HE 25–392 mm).
5a. Build the deck (joists & boards)
- Place pedestals on the grid; drop joists into the saddle head (it grips timber without glue).
- String a line and use the adjuster rings to bring all saddles to the same level.
- Fix deck boards to the joists with the recommended clip spacing; leave ~5 mm gaps for drainage and movement.
5b. Lay pavers (or tiles)
- Place pedestals on the grid; choose the ledge head (with spacer tabs) for even joints.
- Set the first tile on four corners; use the tabs to hold a consistent 3–5 mm joint.
- Work row by row, levelling as you go. Rubber pads on the head stop rattle and protect the tile underside.
6. Level & adjust
Once the first bay is down, run a long spirit level across heads and turn the adjuster rings until the surface is flat. Because each pedestal adjusts independently, you can correct minor slab variations without shimming — that's the main advantage over fixed supports. On self-leveling heads, much of this is automatic.
7. Edge fixing & final check
- Secure perimeter / edge tiles or boards with restraint clips so they can't lift in wind.
- Confirm drainage paths are unobstructed at the slab level.
- Walk the surface: no rocking, no springy spots, even joints. Adjust any outlier pedestal.
- Keep a few spare pedestals and shims on site for later access (e.g. membrane inspection).
Related guides
Choosing the system: How to choose the right pedestal · Rooftop build: Rooftop terrace on pedestals.
Product specs: Deck pedestals · Paver pedestals · Roof pedestals · Heavy-duty pedestals.
Frequently asked questions
Do adjustable pedestals damage the waterproof membrane?
No. Pedestals sit on the membrane and spread the load through a wide base, so they protect rather than puncture it. Use rubber shims or a protection mat under each base on sensitive roofs, and never drag pedestals across the membrane.
Can pedestals be used on a sloped roof?
Yes. Use the self-leveling head (auto-compensates up to ±5°) on sloped or uneven substrates so the finished surface stays flat. For very steep falls, pair it with the slope-corrector option or set a leveling course first.
What spacing should pedestals be?
A typical grid is about 500–600 mm between pedestals. For decking, support joists at ~500 mm centers; for pavers, place a pedestal under each corner of 600×600 mm tiles. Always confirm spacing against the load per pedestal at your finished height.
Do I need adhesive between the pedestal and the paver?
Usually not. Pavers sit in the head's ledge or on a rubber pad and are held by their own weight and the surrounding grid. Adhesive is only needed on ramps, steep edges or where local code requires it. The deck saddle grips timber joists without glue.
How long does it take to install adjustable pedestals?
A typical balcony or small terrace (10–30 m²) takes a crew half a day once pedestals are cut to height. Large rooftops are faster per m² because the grid is repetitive — most of the time is spent on edge fixing and drainage details.
How to install deck pedestals step by step?
Set out a 500–600 mm grid on the slab, place each pedestal with a rubber pad on the membrane, cut joists to span between heads, lay boards with a 5–8 mm gap, then secure the perimeter with restraint clips. That's the short version — the full 7-step walkthrough is the guide above.