Drainage Fall
Gradient 1:N → fall over length
m
Reading 6 m
Lower = steeper. Doc H BS EN 12056-2 minimums apply.
mm
Reading 0 mm
Results
Fall
150mm
Gradient
1:40
Length6 m
Top invert (datum)0 mm
Bottom invert150 mm
Slope2.5 %
Doc H min✓ max 1:40
Suggested Materials
110mm underground soil pipe 3m
2 pc
110mm × 90° bend (or 87.5°)
2 pc
110mm straight coupling
1 pc
Pea shingle bedding 10mm
~50kg per m of trench
1 t
Marker tape — drainage
1 roll
Estimates use standard UK trade rules of thumb. Always check the bag/spec on the day.