Rockbond Lightweight Mortar (RB LWM)

Product information sheet: Rockbond Lightweight Mortar



ROCKBOND LIGHTWEIGHT MORTAR (RB LWM) powder is premixed and ready to use. It consists of a blend of cement powders, graded lightweight aggregates and a union of admixtures. The compound, when mixed with water, produces a lightweight, thixotropic, non flow, non slump, quick set, fibre reinforced, polymer modified mortar, which is easily mixed, worked and placed. The mortar is specially designed to repair soffit concrete, and to fill large volume voids. The powder is packaged in 25kg moisture proof, durable bags and has a shelf life of 5 years.


Special Properties

  • Portland cement based, acrylic resin modified, microsilica enhanced and fibre reinforced.
  • Can be trowelled, floated, sprayed or placed by hand.
  • The material is thixotropic: it liquefies when worked, and gels and stiffens once in place.
  • The mortar, “goes off” as “you go”.
  • Thick sections can be built up on vertical and soffit surfaces in one application.
  • Early strength gain reduces time on site waiting for the material to “go off”.
  • Can be designed and produced to give mortars with densities of 1000kg/m3 to 2000kg/m3.
  • Excellent insulator, and a poor conductor of heat and sound.
  • Fire resistant, non combustible and will not give off toxic gases.
  • High build and high yielding: 1.300 tonnes yields 1m3 of mixed mortar.
  • Economical, non flammable, non toxic, odour free, user friendly and safe to use.


  • In high build situations for use in one application – 60mm or more on soffit surfaces, 75mm or more on vertical surfaces.
  • Whenever a light weight, non flow material is required.
  • Light weight, low density repairs to cementitious materials, concrete, masonry, bricks and blocks.
  • For use as a large volume void filler.
  • To thermally insulate buildings, walls, pipes and ducts.