Troubleshooting Common Adjustable Pedestal Installation Problems

However, even simple projects can encounter unexpected obstacles. If your pavers are wobbly, the terrace seems uneven, or you hear strange creaking, don't panic. Most pedestal installation problems can be easily diagnosed and solved.

Here is a practical troubleshooting guide that will help you identify common problems with adjustable pedestal installation, understand why they occur, and fix them quickly.

When you walk on a newly installed surface, it seems uneven or individual terrace pavers tilt under your feet.

• Uncompensated substrate slope: The base substrate (e.g. drainage membrane on the roof) has a slope to facilitate water drainage, but the pedestal heads were not adjusted to level out this angle.
• Incorrect height adjustment of the pedestals: Individual pedestals were set slightly higher or lower than the adjacent ones.
• Substrate settling or contamination: Soil, construction debris or uneven insulation under the pedestal base prevent it from resting completely flat.
• Please add information that the substrate, for example XPS, may be too soft

• Use slope correctors: Most modern adjustable pedestal systems allow for slope correction both at the base and at the head. Make sure the slope correctors are properly oriented to counteract the angle of the substrate.
• Recheck with a laser level: Use a laser level on top of the pedestal heads before laying pavers or joists, instead of leveling each paver after it has been laid.
• Clean the substrate: Lift the affected pedestal and check the base. Remove gravel, soil, or loose membrane fragments, making sure the pedestal base rests directly on a solid, even surface.

> Manufacturer's tip: When designing pedestal systems, we always emphasize the importance of preparing a clean substrate. Spending an extra five minutes sweeping the installation surface saves hours of later adjustments.

See also: Base slope corrector MAX 8%

A terrace paver or deck board is stable on three corners but rocks back and forth when load is applied to the fourth corner.

• Differences in paver thickness: Minor production deviations in the thickness or flatness of stone or concrete pavers.
• Slight height offset: The pedestal head is a fraction of a millimeter too low in one corner.
• Missing or damaged spacer tabs: The spacer tabs create even gaps, but if one breaks or is missing, the paver shifts out of position.

• Insert shims / leveling shims: Place thin rubber leveling shims directly on the pedestal head under the low corner. The rubber shims cushion the paver while compensating for minor tolerances.
• Rotate the paver: Sometimes rotating the paver by 90 or 180 degrees balances out minor thickness differences.
• Check the spacer tabs: Make sure the integrated spacer tabs on the pedestal head are intact and sit against all adjacent pavers.

See also: Self leveling head SPIRAL & MAX 6% h=20 mm

Walking on a terrace on pedestals causes squeaking, creaking or crunching sounds.

• Debris between the paver and the pedestal: Sand, gravel or soil trapped between the underside of the paver and the plastic pedestal head.
• Direct hard-to-hard contact: Rigid stone or concrete resting directly on hard plastic without acoustic/cushioning pads.
• Joist friction: In joist-supported terrace systems, wooden or aluminium joists rubbing directly against the plastic load-bearing heads without secure fastening.

• Add rubber acoustic shims: Install rubber shims on the heads of each pedestal. These shims absorb shocks, reduce footstep noise and prevent sand from rubbing between surfaces.
• Clean the contact points: Lift the noisy paver and wipe both the pedestal head and the underside of the paver.
• Secure the joists properly: When using a joist structure, make sure the joists are clamped or fixed according to the specific manufacturer's guidelines to stop micro-movements.

See also: Rubber pad SBR 170x170x3 mm

Pavers along walls, parapets, or open edges shift outward, creating wide gaps or dangerous instability.

• Incorrectly removed spacer tabs: Edge pedestals often require cutting or removing specific spacer tabs, which can leave edge pavers unsupported on one side.
• Lack of lateral restraint: Pedestal systems require a rigid boundary (wall, parapet, or edge restraint) to keep the layout in place.
• Overhanging edges: Pavers overhang too far beyond the outer edge of the pedestal head.

• Install perimeter clips or wall spacers: Use dedicated perimeter clips or stainless steel wall spacers at parapet walls. They maintain the expansion gap while preventing the tiles from shifting back toward the structure.
• Use edge restraints on open edges: On open edges without a wall, install a structural restraint or edge profile fixed to the pedestals to lock the perimeter tiles in place.
• Trim the bases correctly: When placing pedestals directly against walls, trim the pedestal bases along the marked cut lines so that the vertical central column sits as close to the edge as possible.

> Manufacturer's tip: In our engineering tests, edge displacement was almost always caused by missing perimeter clips. Never rely on friction alone to keep the edge tiles in place.

See also: 2 mm tile spacer, 3 mm gap + 5 mm spacers – black

Pedestals tilt or sink into the substrate over time, potentially damaging roof membranes or insulation.

• Concentrated point load: A large weight distributed over a small area of the pedestal base pressing into soft insulation or flexible waterproofing.
• Incompatible membranes: Chemical incompatibility between certain plastic materials and specific waterproofing membranes or bituminous coatings.