Raised Access Floor Calculator: Panels, Pedestals and Stringers

What it calculates

For a rectangular room with a raised access floor on a 600 × 600 mm grid, the calculator gives the quantity of each main component:

• floor panels, 600 × 600 mm, including wastage;
• pedestals, one at every grid intersection, labelled with the finished floor height;
• stringers, as running metres and 1.2 m pieces, if the system uses them;
• perimeter edge trim, in running metres;
• cable cut-outs or grommets, as entered.

It is a quantity take-off for budgeting and for checking a supplier's list, not a floor design.

Inputs

Room length and room width are the inside dimensions of the area to be floored, in metres.

Panel size is fixed at 600 × 600 mm, the common modular size for office raised floors.

Stringers can be none, for a stringerless system where panels sit directly on the pedestal heads, or with stringers, which link the pedestal heads along every grid line.

Cable cut-outs / grommets is the number of openings in panels for power and data to come up to desks, floor boxes or equipment. Count them from the furniture and power layout.

Finished floor height is the height from the slab to the top of the panel. It does not change any quantity; it labels the pedestals so the list is complete.

The assumptions panel holds the wastage on panels.

Method

The grid geometry fixes every quantity:

A grid of 600 mm bays across a length L has ceil(L ÷ 0.6) bays and one more grid line than bays, because there is a line at each wall. Pedestals sit where the lines cross. The same lines carry the stringers, so the stringer run is the number of lines in each direction times the length they span.

Assumptions

Wastage is applied to panels only. Pedestals and stringers are counted from the grid, and the installer adds extra supports where needed.

Limitations

• Rectangular rooms only. Split other shapes into rectangles and add them; irregular rooms need more wastage and more perimeter supports.
• The grid is not set out. Where the grid starts decides the size of the cut panels at the walls. A designer centres the grid so cut panels are not thin strips.
• Obstructions are ignored. Columns, risers and floor openings need extra pedestals and cut panels around them.
• No ramps, steps or edges. A change in level at the entrance, a ramp or an exposed edge needs its own fascia, nosing and supports.
• No load class, pedestal type or bracing. Panel load class, pedestal type, adhesive or fixing, bracing and earthing are chosen by the designer to EN 12825 and the manufacturer's tested system. This calculator gives no load values.
• No services. Floor boxes, air grilles for underfloor air and cable trays in the void are measured separately.

Worked example

A 12 m × 9 m office floor with 600 × 600 mm panels, no stringers, 20 cable cut-outs and a 300 mm finished floor height, at the default 5% wastage:

The 336 pedestals are for a 300 mm finished floor height; the supplier chooses the pedestal range that suits it once the panel thickness is known.

If the system needs stringers, select "With stringers". The stringer run becomes 16 × 12 + 21 × 9 = 381 m, which is 318 pieces of 1.2 m.

Twelve metres divides into exactly 20 bays and nine metres into exactly 15, so in this room the grid fits without cut panels if it starts at a wall. The 5% wastage is then mostly spare panels for later replacements.

How engineers use it

A designer or MEP engineer uses a take-off like this when a raised floor is first proposed, often to compare it with surface trunking or ceiling distribution for power and data. The area, panel count and cut-out count are enough for an early budget from suppliers.

Once the layout is drawn, the floor is planned in more detail. The grid is set out on the plan against the walls, columns and core. Areas that need a heavier panel grade, such as server rooms, storage and goods routes, are marked. Floor boxes and cut-outs are placed from the furniture and power layout, and the void depth is coordinated with the floor-to-ceiling height, the door thresholds, the lift lobby levels and any underfloor air. The manufacturer's system then sets the pedestal type, any bracing or stringers, and the fixing to the slab.

When a professional design must replace it

Use the calculator to estimate quantities, compare options and check a supplier's take-off. Replace it with a designer's raised floor layout and the manufacturer's tested system before ordering or installing. That design chooses the panel load class for each area, the pedestal type and height, bracing and stringers, earthing of the floor, and the details at ramps, edges and penetrations, using EN 12825 and the manufacturer's test data.