Extruded polystyrene board, 20 mm thick (2 cm)

Foundations and loaded floors place different demands on insulation from those of a loft. Compare XPS boards, often known as Styrodur, for these locations. They are made of extruded polystyrene with a closed-cell structure. SteelProfil considers XPS where low water uptake and resistance to service loads matter alongside thermal performance.

XPS is suitable for applications such as foundation walls, basements and ground-bearing floors. Closed cells restrict water uptake and rigid boards form a stable insulating layer. Specific grades can also be used in inverted roofs. Match the board to the load and moisture conditions of each application.

• Low water absorption helps retain thermal performance where moisture is present.
• Selecting the right strength allows the boards to insulate assemblies exposed to loads.
• Rigid boards make it easier to set out a continuous layer around a foundation.

Compare the declared mechanical properties of boards for garage floors and utility buildings. Consider the layers above the insulation, the type of load and the design requirements. At a foundation wall, check the junction with the waterproofing. In a suitable build-up XPS helps protect the membrane and maintain thermal continuity at the base of the building.

Board surfaces and edges vary. Profiled edges aid assembly, while texture matters where another layer must adhere. Match these features to the installation method. For a renovated plinth or a new foundation, plan the façade junction and allow for the insulation thickness. When upgrading a basement, boards fitted around this junction connect the wall insulation to the plinth.

SteelProfil supplies XPS in different thicknesses and helps match the order to the budget. Check stock and the grade of each insulation batch. For second-grade material, assess condition, dimensions and suitability. As thickness variations and edges affect laying, calculate the usable quantity for the actual plan.

Compare prices and promotions together with the performance required. List quantities for foundations, plinths and floors separately so each area gets an appropriate XPS grade. SteelProfil can prepare an order on that basis and explain which properties matter at each location.