Choosing EPS beneath a warehouse floor with storage racks

An average based on total stock weight and warehouse area conceals the peaks beneath small base plates. Include vehicle movements, loading docks and crossings. Obtain equipment loads from the supplier for use in the floor design. Mark turning areas at aisle ends. A truck manoeuvring there loads different parts of the slab from one travelling straight down an aisle.

The slab, EPS and sub-base act together. Slab stiffness influences the area through which a rack load reaches the insulation. Thickness, reinforcement, joints and the distance from the rack foot to the slab edge all matter. A single load-spread angle cannot be assumed for every construction.

Check the strength and deformability of all layers, including those beneath the insulation. Settlement of the ground can resemble excessive insulation deformation. A stronger EPS grade cannot repair a weak sub-base. Quality of execution matters too, since uneven ground can leave boards partly unsupported.

CS(10) is the test stress at 10% deformation. A warehouse floor would rarely tolerate that much movement. Use this value to characterise the board. For areas carrying sustained loads, assess the change in thickness over the intended service period.

Creep is the increase in deformation under sustained pressure. Check the declared CC value or other design data for the actual board. NPD means that no performance has been declared for that characteristic. It provides no evidence of zero creep. Obtain the missing data instead of assigning a fixed fraction of CS(10).

Insulation thickness and conductivity determine its thermal resistance. For example, 0.15 m of EPS with λ = 0.035 W/(m·K) gives about 4.29 m²·K/W. Heat loss from a ground-bearing floor also depends on the building geometry, exposed perimeter and ground conditions. Its calculation differs from that for an ordinary external wall.

First identify the required performance under load. Then compare thermal conductivity and thickness among the boards that meet it. Density can help check consistency with a data sheet. Two boards of similar weight can nevertheless have different declared properties.

Pipes, ducts and recesses can interrupt the insulation or alter how the slab is supported. Coordinate them with rack positions. Beneath heavily loaded feet, avoid voids and small unstable pieces of board that leave the slab without consistent support.

Lay successive layers of EPS level and with staggered joints. The damp-proof layer has its own function, and damage may only become apparent after the concrete has been placed. Before pouring, inspect the base, continuity of the layers and board identification against the drawings.

State industrial floor use, mechanical requirements, conductivity and thickness in the order. Refer to the design so the description does more than call for hard polystyrene. On a large job, retain board labels and batch references to identify the material after installation.

EPS manufacturers include Paneltech, Genderka, Austrotherm and Enerpor. Compare specific boards using documented performance. Complete the floor specification before ordering racks and building the floor. If the forces at rack feet change later, reassess the floor even if its surface appears intact.