G4 is a moisture cured polyurethane which forms a non-porous seal on concrete, brick and porous stone. G4 uses the moisture in the air and substrate to cure and harden.

G4-Colours. When using coloured G4 the first two coats must be G4 clear. This is because the G4 clear provides the maximum non porous seal and adhesion. A further two coats of G4 coloured can now be added. G4 Coloured system- Application 1st & 2nd coats= clear 410gram/metre sq.(for 2 coats) 3rd & 4th coats= coloured 400gram/metre sq. (for 2 coats)