DrainFlex features long coil lengths, is flexible and lightweight making it easy to install using a backhoe, chain digger or ploughing directly into the ground.
The minimum suggested coverage (not subject to vehicular loadings) is 300 mm. The trench should be as narrow as possible but large enough to allow backfill and compaction of the bedding material. In poorly drained areas, more than one trench may be required.
When you intend to use DrainFlex in fine sand and coarse silt soils, a polyester filter sock may need to be used to prevent fine grains from entering the slotted pipe. The filter sock stabilises the soil by connecting the corrugations, supporting the soil around the pipe and preventing deposits from entering the pipe.
Heavy Duty Polyester Roads and Maritime Services NSW (RMS) approved filter socks can be supplied to meet these requirements.
Dig a trench as narrow as practicable allowing for approximately 300 mm minimum cover height and 100 mm (both) side clearance, with a fall of 1% or 1:100.
For agricultural applications we suggest a minimum 700 mm cover height which should be maintained. This should minimise any potential damage from machine and equipment.
Fill the bottom 50mm of the trench with filter aggregate. This will take out any irregularities in the bed of the trench.
Install DrainFlex into the middle of trench and ensure that a minimum cover of 180 mm is achieved (on top and sides of the DrainFlex); we suggest that a maximum filter aggregate of 13 mm should be used for the backfill.
The above two features provide a filter zone.
Replace the topsoil over the filter material aggregate.