Thin Joint Mortar

Thin Joint Mortar is a Portland cement based powder mix which is polymer modified. The formulation includes selected high quality graded sands, special shrinkage compensating components plus powerful plasticising agents which produce a workable thixotropic mortar at a low water content. The resulting mix enables thin joints between thermal blocks to be made. Horizontal and vertical joints are formed down to 3mm in thickness. These thin joints contribute to the maintenance of built wall U-values. Thin Joint Mortar is supplied ready for on site use requiring only the addition of measured mixing water. The mixed mortar will remain workable for two hours with periodic agitation. Once mixed the mortar is placed using a notched trowel along horizontal and vertical joint lines. The thixotropy of the placed mortar plus a high early “grab” between blocks produces stability in the blockwork sections during construction. Overhangends of block courses are stable and do not require any special support. Thin Bed Mortar joints are suitable for external and internal leaf construction giving strong joints suitable for the erection of load bearing wall sections.


Thin Joint Mortar is used in conjunction with Durox Blocks to provide builders with a fast build thermally efficient system for all types of buildings.


  • Increased thermal performance.
  • Dramatically reduced build time.
  • Completely waterproof walls.
  • Low maintenance costs.
  • No cold bridging.
  • No thermal stress in the structure.
  • Factory blended and quality assured.
  • Available in grey or beige.

Product Downloads

Thin Joint Mortar technical spec sheet
Thin Joint Mortar Material Safety Datasheet
Thin Joint Mortar

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