Insulation as a barrier against cold from below

Why is good floor insulation so important?

Nobody wants cold feet, in winter or in summer!

The most effective way to keep "cold from below" from passing through the foundation into the house is to place pressure-resistant insulation directly under the foundation slab.

With this method the insulating effect is so good that even low ground temperatures, well below 10 °C, are not felt at all on the inside of the floor slab.

Ideally the barrier against cold consists of insulation boards that also resist high compressive loads — strength class 50 or 70 (the figures stand for a compressive strength of 50 t/m² or 70 t/m² at 10% deformation).

These insulation boards are so strong that the whole building can stand on them.

For "light" buildings without a basement, an XPS board of strength class 30 is enough. As soon as a building has a basement, a ground floor and at least one storey above, an XPS board of class 50 is recommended. For multi-storey buildings, with high loads from above, we recommend class 70 XPS boards — especially at retaining walls and under load-bearing columns, where high point loads act on the foundation insulation. For passive houses the usual insulation thickness is between 10 cm and 20 cm.

Warm and solid floors!

Dry screeds are increasingly used instead of concrete screeds (which are laid wet). Dry screed boards consist of gypsum-fibre boards (20 mm thick), gypsum boards or various wood-based panels. To take the usual loads in offices and homes, we recommend Austrotherm XPS 50 boards, 30 mm to 50 mm thick. Furniture can then be placed on them without any problem, and running services through the insulation is easy, as XPS boards are simply cut with a good utility knife.

Insulating the garage against frost

More and more often our pressure-resistant Austrotherm XPS 50 or Austrotherm XPS 70 is laid under the screed in garages, above all to create a more pleasant, frost-free climate in winter. As garage screeds are usually 80 mm to 150 mm thick, we recommend Austrotherm XPS 70 boards 60 mm to 120 mm thick to transfer the wheel loads safely — bearing in mind that cars will keep getting bigger and heavier, not least for safety reasons.

Car parks with good, "solid" insulation

Today almost every shop and office building has car parking, either above the basement or on the flat roof. The necessary insulation and the build-up must safely take the loads of parked vehicles. In many cases only Austrotherm XPS 70 meets these requirements.

Insulation and formwork in one: the Austrotherm foundation insulation system

The Austrotherm foundation insulation system ensures quick and safe insulation under the foundation slab. It is a formwork and an insulation system at the same time and meets the highest requirements for compressive strength and water resistance.

The system is designed for foundation slabs carrying high loads, as in multi-storey buildings of all kinds and in industrial buildings. It is also suitable for the standardised moisture seal of the basement, i.e. the connection between horizontal and vertical waterproofing required by the technical standards. The whole building is practically wrapped in one thermal envelope, avoiding harmful thermal bridges.