How to reduce thermal bridging where an industrial floor meets the wall

A masonry service room and a lightweight panel wall meet the floor differently. Draw each junction to its actual dimensions. Overlay the structural and insulation details to see whether the foundation, slab edge and wall insulation meet as intended.

Heat can escape along the whole wall-to-floor junction. A column or bracket adds a more localised path. The thermal conductivity of EPS describes the board itself. A calculation for the uninterrupted floor area can miss both types of bridge, so assess the junctions separately.

In a long hall even a small extra heat flow per metre can add up. Check the internal surface temperature at the wall foot as well. At a given indoor humidity a cold edge may be prone to condensation. If damp patches appear, investigate water ingress and ventilation before attributing them to the thermal bridge.

Under the slab, check the pressure the insulation will carry and its deformation under prolonged loading. Against the foundation wall, soil pressure and moisture exposure also matter. Check the intended use, CS(10), long-term compression data and, where relevant, water absorption. The two locations may require different EPS grades.

Even EPS with reduced water absorption needs a continuous moisture protection detail at the plinth. Follow the waterproofing through changes of level at doors and gates. Increasing the board thickness cannot close a leak. Check that adhesives and protection layers suit both the EPS and the waterproofing system.

Never insert an ordinary EPS board beneath a load-bearing column as an improvised thermal break. The structural design must establish how the load reaches the foundation. A specially designed bearing detail may be needed. A high CS(10) value alone does not establish the board’s suitability as a structural bearing.

Coordinate the edge insulation with the slab bearings and movement joints. Identify where the floor must move relative to the wall. A rigid infill can restrain that movement or change the way forces are transferred. Detail the thermal insulation and the movement joint together.

At the entrance, wheels repeatedly load the slab edge and rainwater can reach the threshold. Allow for drainage, wheel pressure and the door’s bottom seal. Abruptly thinning the EPS can create a thermal bridge, while an inadequately supported insert can leave the slab edge vulnerable to loading.

Set the internal floor level, external paving level and falls before pouring concrete. Once the door is fitted, there is little room for adjustment. Show any change of insulation material or local reinforcement on the drawing before the installers cut the final boards.

Before backfilling the foundation or laying the floor, inspect column bases, corners and service penetrations. Photograph the layer sequence and thicknesses. Defects at the perimeter are hard to see from the middle of the slab and difficult to repair later. Thermography can help diagnose a finished building under suitable conditions, but inspections during installation reveal the actual joints and board thicknesses.

EPS board manufacturers include Enerpor, Paneltech, Arsanit and Austrotherm. Compare products for the particular floor, foundation or plinth zone. Use the coordinated section at ordering and handover to check that the insulation shown at the hall edge was actually fitted and that the slab has the specified support.