Frequently Asked Questions

LifeRain™ Modular Rain Water Harvesting FAQs

  • Can tree roots penetrate the waterproofing liner? +

    No, not unless the waterproof liner has been punctured or torn. Additional protection can be provided by using a root barrier of geotextile outside the liner.

  • How are the waterproofing liners joined? +

    The waterproofing liner is heat-sealed by a poly welder. The liner is available in 8m wide lengths. The optimum tank configuration would be designed to prevent having to poly weld the liner.

  • What effect does this water motion have on the water quality? +

    The continuous motion provides additional surface area for aerobic decomposition and prevents stratification (layering) of the water.

  • How do you inspect LifeRain™ tank modules? +

    Inspection holes can be places through the center of tank if required.

  • How to you prevent LifeRain™ tank modules silting up? +

    Filtering the water before it enters the tank with a LifeRain™ filteration unit will prevent the LifeRain™ tank Module from silting up. Good housekeeping during installation and ensuring that the inlet pipes were adequately sealed will also prevent the LifeRain™ tank modules from silting up. Through Geotextile and sand only pure water can have access to the Life Green tank.

  • How to prevent geotextile to clog up? +

    The LifeRain™ tank modules should be completely surrounded by a layer of 300mm coarse washed river sand with no fines compacted to 95% density on both the top and the sides of the tank.

  • How do we know that the retained water in the LifeRain™ tank modules is in continuous motion? +

    The capillary action of the water within the sand provides continues motion

  • Who can join the waterproofing liner? +

    Poly Welders. They can be found in your local yellow pages.

  • What is the purpose of the geotextile? +

    The geotextile prevents the surrounding bed of sand from entering the tank and protects the waterproof liner from any potential sharp edges.

  • Can I drive over the tank? +


  • What size does my excavation need to be? +

    Your excavation needs to allow minimum of 300mm on each side of the tank for adequate compaction of backfill materials. The depth of the tank should allow 100mm below the LifeRain™ tank modules and 300-500m above the tank on whether vehicular traffic is expected,

  • What maintenance is required for the tank modules? +


  • What maintenance is required for the filtration unit? +

    The filtration unit should be regularly cleaned out after rainfall and washed.

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Roof Garden/ LifeCell FAQs

  • How do you prevent geotextile from clogging? +

    Ensure that a layer of 100-150 mm coarse washed river sand with no fines is placed on top of the geotextile. The backfill material should be coarse and free draining.

  • What backfill material do I use? +

    Permeable clean sand, coarse backfill, taking care to avoid punctures or dislodging of the liner. Paving materials such as brick, concrete pavers and slabs, wood decking, stone slabs, etc. can be placed directly upon the fabric – provided the edges of the materials will not tear or puncture the fabric during handling. This will allow weight to be minimized. Traditional setting beds of sand, or lightweight aggregate and cement binder (allowing for infiltration) between the filter fabric and the paver.

  • Do I need to use protection board? +

    No. Protection board is not required.

  • Can I use it in trafficable areas? +

    Yes. The 30mm LifeCell requires 500mm of fill compacted to 95% at 300mm intervals for vehicular traffic and 300mm compacted fill for pedestrian traffic. The 52m LifeCell doesn’t require compacted fill.

  • Can I cut the Drainage cell? +

    The drainage cell can be cut with a circular saw or hacksaw. Take care that the rough edges do not puncture the geotextile or waterproof liner (if used).

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