Structure Undermining Calculator

Preliminary screening for whether pool excavation may extend into the support zone of an existing nearby house or structure.

Calculator mode

Assessment Minimum setback

Distance from pool excavation to structure

Measure horizontally from the nearest edge of the proposed pool excavation to the nearest edge of the existing structure.

If the excavation extends outside the pool shell, use the distance from the actual excavation edge to the structure where known.

Maximum pool excavation depth

m below ground

Enter the maximum excavation depth below existing ground level.

Edge Type

Normal Right Angle Vertical wall with square bottom corner. Safety Ledge 600 mm deep by 500 mm wide step. 60° Radius Curved profile, calculated conservatively.

Depth of structure footing

m below ground

Enter the depth from existing ground level to the underside of the footing nearest the proposed excavation.

Do you have a soil test showing the soil profile?

No Yes

No soil test mode uses two theoretical scenarios: 45 degree clay and 30 degree sandy soil / fill.

Cross-section

Footing support diagram

Common X/Y scale