Soil test (SBC) report: what it must contain before you build
On your checklist as: “Soil test (SBC) completed”
Your foundation type and its cost are decided by what the soil can bear. Skip the test and the contractor decides your foundation by habit - and any surprise underground becomes a mid-build extra bill.
What to look at
- Borehole or trial-pit logs with depths
- Recorded water level
- SPT N-values
- SBC at the design founding depth, on the IS 6403 basis
How to check it yourself
A competent report states the number, location and depth of boreholes or trial pits, the tests run, the ground-water table, and the safe bearing capacity AT A STATED FOUNDING DEPTH with a foundation recommendation. IS 1892 covers exploration-point number, spacing and depth, with guidance to about 1.5 times the foundation width below founding level. IS 6403 gives the net-safe-bearing-capacity method for shallow foundations. An SBC quoted without a depth and a method is meaningless.
Where this comes from: IS 1892:2021 (supersedes IS 1892:1979); IS 6403:1981 (reaffirmed 1997); IS 2131:1981 (SPT) (indian standard or building code)
More plot and land checks before you build
- Land documents verified
- Building rules feasibility checked
- Utilities and site risks screened
- Paddy land Data Bank status checked
- Coastal zone screen done
- Encumbrance certificate obtained
- Designer has visited the plot
- Measured survey plan in hand