Posted by Luke Quentel, on July 10, 2024.
All of the calculations are based on using a well graded gravel material to backfill with. Non regular pea gravel or shingle is ideal, between eight and sixteen millimetres thick. Ten is usually the most commonly available size. The tank should be graded around the sides and also a hundred-millimetre underneath, on top you can use added material or SXF2 or type one. But all size touching the tank should be in a well graded, roughly 10-millimetre pea shingle.