Roof Primer GacoFlex E5320 Kit, Epoxy 2 gallon Epoxy 400′-500′ coverage por | 17 Jul 2026When reduced one pint (.47 L) of water per gallon (.5 L per 3.78L) of mixed GacoFlex E-5320 and applied to smooth concrete, the coverage is one gallon per 200 to 250 square feet (3.78 L / 18.6 to 23.2m2).