3 ms·
6 ft so the ground does freeze/melt and the structure become uneven.
by wolco 7y ago
6 ft so the ground does freeze/melt and the structure become uneven.
- sgc 7y agoIt's actually calculated based on the frost line for the area. I don't think when building on solid rock it matters, since the point is to avoid expansion and contraction of freeze thaw cycle pushing the house up.
- jefftk 7y agoThis depends enormously on where you are: https://www.fhwa.dot.gov/publications/research/infrastructure/pavements/ltpp/08057/07.cfm https://www.fhwa.dot.gov/publications/research/infrastructur... Go farther South and it gets down to eventually nothing. Go far enough North, to permafrost country, and you not only need to dig down to the permafrost but you need to have insulation so the permafrost doesn't melt.