Basement insulation

The basement insulation is the insulation of the basement against the surrounding soil ( perimeter insulation ). In the case of unheated basement floors, the basement insulation can also be installed under the basement ceiling (see calculation rules in the Energy Saving Ordinance ). In terms of design and materials, it resembles roof insulation (hardly at risk from moisture). Compared to the rest of the building envelope, however, a combination of insulation and thermal insulation is required in the area of ​​the perimeter insulation due to the increased earth pressure and the existing moisture .

In a multi-layer construction, the (still) exposed or to be exposed masonry / concrete structure is first sealed against moisture. For this purpose, mostly bituminous materials are used. In the past, strips were often attached with adhesive dots. Nowadays, one or two-component liquids are applied directly to the cellar wall after a primer. This moisture barrier layer should extend up to 60 cm above the top edge of the soil / floor covering in order to also cover the splash water area. The actual thermal insulation is glued to it. This must be insensitive to moisture. Extruded rigid polystyrene foam and foam glass are considered reliable . If the soil is cohesive (poorly water-conducting), a drainage mat must be attached, which prevents water build-up and ensures that the water is drained off to the drainage point . In some municipalities, however, this recommendation may not be followed for reasons of flood protection (retention of rainwater). As far as possible, septic tanks can / should / must be used there .