Swelltite is a sheet membrane product (made up of 5% Butyl Rubber and 95% Sodium Bentonite mix applied to a geomembrane).  It is used predominantly on block walls, pre-cast panels, garden planter boxes and plaza decks. The product has a heavy-duty backing, meaning there is often no need to use a protection board if you use 25/7 scoria.  Swelltite can be nailed or glued to a block wall and precast and then immediately back-filled with 25/7 scoria and compacted at 200mm layers. It can be applied to green concrete, which gives the advantage of not having to wait for the concrete to cure, this is an advantage especially for split slab construction where time is of essence.


  • Can be applied to green concrete – thus saving time/money
  • Can be applied in inclement weather – thus saving time/money
  • Meets the New Zealand Building Code durability requirement of 50 years
  • Self-healing
  • Can be nailed
  • Can be easily joined in the most difficult places and is excellent for penetrations
  • 50mm lap at joints
  • Can be applied to concrete block walls, pre-cast panels, split slab construction, car-park and basement roofs plus planters and garden roofs
  • No protection required if back fill is less than 25mm diameter scoria