Pedestal choice starts with the required finished floor level, but height alone does not determine the right system.

Wallbarn balance pedestals used for external paving. Suspended paving system.

Across terraces, balconies, podiums and raised external areas, the pedestal also has to suit the surface above it, the falls in the subfloor and the way the area will be used. Depending on the project, it may support paving directly, timber or composite joists, or an aluminium rail system.

Start with the available height
The first check is the distance between the subfloor and the required finished floor level.

Wallbarn offers fixed-height and adjustable plastic pedestal ranges for different height requirements. Fixed Height Pedestals suit low installations where adjustment is not required. MiniPad provides low-height adjustment, while Universal, Balance and Mega Balance cover progressively deeper and more variable installations.

Using a range with far more adjustment than the project needs can add unnecessary cost. A range without enough capacity may simply be unable to reach the required height across part of the area.

Consider the falls in the subfloor
External subfloors are generally laid to a fall for drainage, typically somewhere between 1 in 100 and 1 in 20 depending on the project.

Adjustable pedestals allow the paving or decking above to be brought to a level finish without following the slope beneath. Different pedestal heights compensate for the changing distance between the subfloor and the surface above.

Balance and Mega Balance Pedestals both have pivoting headpieces that can accommodate falls up to 5%, equivalent to 2.86 degrees or a 1 in 20 fall.

The drainage falls below are retained. Water passes through the gaps in the paving or decking and continues across the subfloor towards the drainage points.

Match the pedestal to the surface above
Paving, decking and rail-supported systems place different demands on the pedestal connection.

Some pedestal ranges support paving directly through paving lugs or dedicated paving headpieces. Others can support timber, composite or aluminium joists. Wallbarn aluminium rails can also be integrated with specific pedestal and headpiece combinations.

This becomes particularly relevant on schemes with mixed finishes or where part of the area requires a rail-supported substructure rather than direct support from individual pedestal heads.

Not every pedestal range connects to every system in the same way, so the headpiece and finished surface need to be established before the pedestal specification is finalised.

Traffic and use also affect the decision
A residential balcony with light furniture places different demands on the support system from a communal terrace carrying heavy planters, substantial furniture or other concentrated loads.

Those conditions can change pedestal type and placement. On larger schemes, one area may use a standard pedestal arrangement while zones beneath heavy planters or other localised loads use a different pedestal range or spacing.

Heavy objects, fixed features and concentrated loads therefore need to be identified early rather than treated as an installation-stage detail.

Check the whole layout before ordering
For an early estimate, pedestal quantities can often be calculated from basic information.

For paving, slab or tile size and total area may be enough. For decking, joist size, joist centres and overall area can provide a reasonable starting point.

Before an order is finalised, Wallbarn can review drawings, finished floor levels, drainage points, awkward interfaces and how the area will be used. Photos or videos may also be useful, and some projects may justify a site visit.

A quick estimate might suggest that a project needs around 1,000 pedestals. A detailed review can establish which pedestal ranges are required, where each range applies and which accessories or rail components are required.

Missing components, incorrect quantities or unsuitable pedestal types can delay installation and create costs that were never visible in the original square-metre estimate.

If you want assistance choosing the right pedestal and get accurate estimates, speak with Wallbarn's Technical Team.