Thermal refurbishment of a single family home

37213 Witzenhausen

Drills: 8
Depth: 320
Year: 2013

Borehole grouting with the quality material Fischer GeoSolid® 240HS

Due to the special geology (assumption of Karst cavities) the depth of the borehole was limited to 40m. Because of the size and the location of the property (drilling point in the backyard, behind the house) the only possibility was the radial drilling. This procedure is drilled star shaped out of a central shaft. The advantage was that this procedure is gentle and does not devastate the property. For the backfilling material of the geothermal probes Fischer GeoSolid® 240HS was chosen. 

Geology, stratigraphy, characteristics

The weathering layer consists of fine clay, followed by sandstone and clay layers. Starting at 36m the sandstone was harder and gaps were found. To prevent losses of the suspension, Fischer geothermal hose was used. 

Drilling method, piping, drilling equipment

The borehole was drilled with the cable tool percussion drilling procedure with a 96mm drilling tool and a 115mm casing (36m). 

Details of the grouting process

It was grouted with the contractor method with a colloidal mixer (MAT). The sulphate, saltwater and carbon dioxide resistant grouting material Fischer GeoSolid® 240HS was used. The high frost-thaw stability was very important to the customer. Also the Fischer geothermal hose was used to prevent losses of the suspension.

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