Insulation of the Base plate, Walls & Ceilings

High heat losses also occur above uninsulated floor slabs, ceilings and walls adjacent to unheated rooms. The GEG (Building Energy Act) also specifies minimum requirements for heat transfer coefficients here: U=0.24 W/m2K. Thermal insulation measures in these constructions are also often possible with a relatively low labor and financial outlay and can be carried out on one's own without special craftsmanship skills.

Renovation of the Floor Slab

Before the thermal insulation is applied to floor slabs, damages must be repaired and moisture barriers installed. 

Leaks often occur in the area where the floor slab joins the adjacent walls. 

If the throat between the floor slab and the basement wall leaks, it must be chiseled out and replaced

Horizontal Moisture Barrier

If the horizontal moisture barrier is missing, water can rise upwards through the base plate.

Sealing membranes or bitumen coatings applied to hydrophobized concrete surfaces are suitable for sealing.

This method is not suitable for pressurized water.

Thermal Insulation Above the Base Plate

The thermal insulation can consist of various moisture-resistant building materials, e.g., polystyrene, mineral foam, or foam glass.

Screed & Tiles

For acoustic reasons, the screed must be separated from the walls and pillars by a moisture-proof foam strip.

A dry or wet screed can be chosen as a finishing touch and a floor covering, e.g., of ceramic tiles, wood, or plastic can be laid.

The Inner Walls

Larger energy losses can also occur through walls that border on unheated rooms; because the higher the temperature difference between heated and unheated rooms, the greater the heat loss. 

The heat loss from heated to unheated rooms must be limited by thermal insulation measures following the German Energy Saving Ordinance. 

For reasons of building physics, the thermal insulation should be installed on the cold side of the wall to prevent condensation of moisture in the wall.

Thermal Insulation Inner Wall

For the thermal insulation of such walls, various insulating materials are suitable, e.g., cork, polystyrene, or mineral panels. 

Thermal insulation made of mineral wool is placed, e.g., between wooden profiles. In this case, the panels should be installed with a low pre-stress between the wooden or metal profiles. 

Plasterboard or wood fiberboards are suitable for the cladding.

Walls against Unheated Rooms

Thermal insulation panels can also be used for thermal insulation of interior walls bordering unheated rooms.

They consist of, e.g., polystyrene, cork, or mineral foam.

After checking and preparing the wall surfaces, the adhesive mortar is applied to the insulation board. 

The insulation board prepared in this way is glued to the load-bearing substrate.

In the case of non-load-bearing walls, fixing with dowels is possible.

Ceilings Against Unheated Rooms

A further thermal bridge of the building can be created by ceilings bordering on unheated rooms.

Thermal Insulation Above the Ceiling

Ceilings that are not used for walking can be covered with mineral wool.

For accessible ceilings, a heat insulation layer of perlite, crushed cork, or cellulose, for example, is suitable as thermal insulation, which is placed between wooden beams and covered with wood planks or wood fiberboards.

Alternatively, thermal insulation made of polystyrene or mineral foam can be chosen, which is covered with a flowing or dry screed. 

The dry screed is preferable because no additional moisture is introduced.

The Collar Beam Ceiling

Valley beam ceilings, which delimit heated rooms at the top, must also be sufficiently thermally insulated. Before taking the appropriate measures, the position of the beams must be checked for sufficient load-bearing capacity.

The thermal insulation can also consist of different insulating materials, e.g., cellulose. The insulation material is placed on a tightly closing formwork, which is laid between the beams.

In the case of insulation fill, the space between the beams must be lined with a tear-resistant paper. A floor covering can then be applied. A foam carpet pad, placed between the floor covering and wooden profiles, reduces the transmission of impact sound.

Thermal insulation with cellose

Ceiling to an Unheated Basement

For thermal insulation under the basement ceiling, insulation boards, e.g. ,made of polystyrene, cork, or mineral foam, are suitable.

They can be glued to a load-bearing substrate directly after checking and preparing the ceiling.

For non-load-bearing ceilings, they can be fixed with dowels.