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Dual Seal Mastic

Bituminous Mastic

Key Features

  • Bituminous mastic
  • Trowelling consistency
  • Easy to fix
  • Effective barrier to transmission of water
  • For crack filling and sealing
  • Compatible with the Dual Seal system

What is Dual Seal Mastic?

A trowlable mastic comprising a special formulation of expandable minerals and elastomeric compound which expands and stiffens in the presence of water to form a water proof barrier.

Dual Seal Mastic in Use

For use with DUAL SEAL waterproofing membranes to form a 450 fillet in internal corners, around pipe entries and any penetrations. It is also used for filling Voids, tie holes and any honeycombing, prior to installation of the DUAL SEAL membrane.

Technical Data


Expandable minerals and elastomeric compounds.


Grey/ Black

H20 Resistance



10 x 10 -10 coefficient

Specific Gravity



Supplied in 19 litre pails