In Ground Sitting - Correct Method

1. Before commencing, check for underground pipes and ensure excavation work does not infringe on the weight bearing capacity of adjacent structures.
Excavate the hole in depth to allow for 50-75 mm of bedding material and a maximum depth of 1/3 of the tank wall height. Excavate the hole in diameter to allow for a 150-200 mm gap between the tank wall and the surrounding soil.
The site is not suitable if there is water seepage or if the floor of the hole is unstable. Spread washed river sand into the hole and compact it with a plate compactor, to provide a fi rm level base. Check that no rocks, roots or sharp objects penetrate the sand base.

2. Tank must be lowered into the hole squarely by crane. (Crane hire at purchaser’s expense.)

3. Prior to starting to backfi ll, the tank must be filled with water to a level marginally above ground height. The soil taken from the hole must not be used as the backfi ll under any circumstances.
Spread a 200 - 300 mm layer of sand around the base of the tank. Manually compact the sand ensuring that all the voids are fi lled. Continue adding the sand in 200 - 300 mm layers, ensuring each time that it is well compacted into all areas until it comes to within 150 mm of the surface. Restore the remaining 150 mm with fresh soil.

CONTINUE UNDER ABOVE GROUND SITING STEP 4