DRILLED PIER METHOD (OUR METHOD)
- Most widely recommended by structural engineers.
- Used in large building construction.
- Extends below active soil depths.
- Not affected by moisture variations, (most common cause of foundation problems.)
- Float resistance due to widened portion at the top of the pier.
- Bearing support at the bottom where the soil is denser and more compressed.
- Angle installation for proper placement under the foundation grade beam.
- Greater friction between the pier and surrounding soil.
SPREAD FOOTING METHOD
- Concrete pad approximately 2' square by 1' thick.
-Only extends to a depth of 2' to 3'.
- Not below active soil nor resistant to moisture variations.
-Considered to be a temporary solution by
- Less effective than drilled piers.
- Steel pipe or concrete segments driven into the ground against the weight of the structure.
- No way of verifying that the pipe or concrete segments are straight.
- In dry, hard soil conditions these piers cannot be driven
to adequate depths before the structure begins to rise.
- Very expensive. $$$
-Much smaller piers, have no conical friction capacity.