Record: Soil and sand source, chalk quantity, treatment method and hold time, casing date and depth.
Collect loam soil and sand a week before the bags colonise.
Mix three parts soil to one part sand and add chalk powder.
Treat the mixture by an approved method and keep it covered.
Uncover 24 hours before casing and turn it once.
Case every bag to the same depth using a cut levelling stick.

