Roof
roof pitch
Drempel
Flat roof
Upper floor slab
Solid ceiling
timber-beamed ceiling
Nail binder
Attic conversion
External wall
Façade
Partition joint in a house
cellar wall
Ground floor
cellar ceiling
Stairway to the cellar
Solid ceiling
Cap ceiling
Timber joist floor/cavity
Special components
Flatts in pitched-roof buildings often have knee walls separated from the roof slope. The partition wall separating the living area from the roof space – usually around 80 cm high – is made either of a lightweight concrete slab, a lightweight wood wool board or wood-based panels. Brick partition walls made of solid bricks or river stones are also found. There are often small openings through which one can access the cavity. In older buildings, neither the floor – consisting of concrete or timber-beam ceilings – nor the sloping roof surfaces nor the partition wall separating the loft from the living space are insulated. Heat loss through the concrete ceiling (from the floor below upwards) or through the knee wall partition is very high.
The insulation process for the party wall and the floor consists of several steps. Firstly, the party wall is insulated from the outside within the cavity using high-quality, high-performance insulation boards, such as rigid polyurethane (PU) foam or phenolic resin. The insulation boards are fitted tightly together and securely fixed to the wall to form a continuous layer of insulation and prevent thermal bridges. All joints and connections are then carefully sealed to create an airtight layer and prevent the ingress of moisture.
Horizontal insulation is then applied to the floor slab to insulate the floor. Here too, high-quality, high-performance insulation boards are used and laid seamlessly to create an effective layer of insulation.
For wall insulation, the recommended thickness of the insulation boards is at least 100 mm. The floor should be insulated to the greatest possible thickness.
All the benefits at a glance
Further benefits:
- Draughts are eliminated
- Comfort is enhanced due to higher temperatures on the inside of the external walls and beneath the ceiling
- Mould in the corners of the room beneath the lintel disappears
- CO₂ emissions are reduced
- The work is minimally invasive
Can I install the insulation myself? You can carry out the insulation work yourself; however, to ensure that the insulation functions as intended, it should be carried out by a specialist contractor. Unfortunately, DIY work on this part of the building is not eligible for funding, as the required minimum cost of €2,000 for materials is almost never reached.