Retrofit insulation of the cellar ceiling
The insulation of the ceiling to unheated cellar rooms from below is a simple and generally cost-effective measure to improve the energy quality of a building. A personal contribution by the owner is possible. The prerequisites for the measure are accessibility and sufficient remaining room height.
An alternative is insulation of the upper side of the ceiling, i.e. through alteration of the floor construction in the storey above.
The achieved energy cost savings of a thermal insulation of a cellar ceiling also depend on the initial state.
U-values of selected constructions
Among other things, the energy performance of cellar ceiling depends on the existing construction. Depending on the age of the building and on the region, a variety of constructions can be found. The age of the building alone only allows a limited inference of the energy quality.
The following table shows exemplary U-values of frequent constructions. Cellar ceilings are often designed as solid structures.
|Timber beam ceiling||bis 1918||16 cm timber beam/puddle clay, 2 cm shelves, 2,5 cm floor board||1,13|
|Vaulted ceiling||bis 1948||12 cm vaulted ceiling solid brick, 12 cm flooring sleeper/filling, 2,5 cm floor board||1,10|
|Concrete ceiling||1919 - 49||16 cm concrete ceiling, 6 cm bonded screed||1,94|
|Concrete ceiling||1949 - 57||15 cm concrete ceiling, 2,5 cm insulation, 1cm floor screed||0,93|
|Concrete ceiling||1969 - 78||14 cm concrete ceiling, 4 cm insulation, 4 cm floating floor||0,68|
|Concrete ceiling, insulated*||refurbished||15 cm concrete ceiling, 4 cm insulation, 4 cm floating floor, 12 cm insulation||0,22|
Source: [Source: Zentrum für umweltbewusstes Bauen e. V.
* own calculations (solidar planungswerkstatt using www.u-wert.net)]