Hello,
we are building a single-family house, two floors, approximately 160 sqm (1,722 sq ft). According to the soil report, we need to dig down to 1.4 m (4.6 ft). In addition, a frost barrier according to DIN standards must be installed, or alternatively a frost-resistant bedding under the foundation slab (which is not DIN compliant).
"The installation of a frost barrier can be omitted if frost-resistant and frost-safe material, such as natural crushed stone, basalt lava, or clay-free gravel with a graded grain size of 0/45, is used and compacted for the necessary ground filling."
Our general contractor recommends basalt lava or crushed stone (as requested in the excavation subcontractor form) compacted in layers under the foundation slab, since the soil is soft. He advises against the frost barrier because interruptions in the bedding can potentially lead to settling.
However, basalt is far too expensive. As an alternative, the excavation contractor suggests mountain gravel (frost protection gravel, locally common with report), which is also affordable.
We are now uncertain: first, a bedding that is not DIN compliant, and second, gravel that often contains clay, report or not... The foundation is probably the most important part of the construction, or are we being too critical?
What would you recommend?
Regards,
body123
we are building a single-family house, two floors, approximately 160 sqm (1,722 sq ft). According to the soil report, we need to dig down to 1.4 m (4.6 ft). In addition, a frost barrier according to DIN standards must be installed, or alternatively a frost-resistant bedding under the foundation slab (which is not DIN compliant).
"The installation of a frost barrier can be omitted if frost-resistant and frost-safe material, such as natural crushed stone, basalt lava, or clay-free gravel with a graded grain size of 0/45, is used and compacted for the necessary ground filling."
Our general contractor recommends basalt lava or crushed stone (as requested in the excavation subcontractor form) compacted in layers under the foundation slab, since the soil is soft. He advises against the frost barrier because interruptions in the bedding can potentially lead to settling.
However, basalt is far too expensive. As an alternative, the excavation contractor suggests mountain gravel (frost protection gravel, locally common with report), which is also affordable.
We are now uncertain: first, a bedding that is not DIN compliant, and second, gravel that often contains clay, report or not... The foundation is probably the most important part of the construction, or are we being too critical?
What would you recommend?
Regards,
body123
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