ISOPLAST FC/A | 2-component polyurea membrane

ISOPLAST FC/A is a multi-component, coloured, solvent-based, liquid-applied polyurea waterproofing membrane with a high solids content (~85% by weight). Mixing ratio 70:30 (A:B), white colour.

Its mechanical performance is at the top of its class amongst liquid-applied membranes: tensile strength of 8 MPa and elongation of 350% according to ASTM D 412, with adhesion to concrete ≥3.2 N/mm² (ASTM D 903) — more than double that of single-component polyurethanes. Water absorption is zero (0.00 kg/m²·min⁰·⁵) and its properties are maintained from -40°C to +90°C.

The working time is extremely short: pot life ~30 minutes, workability ~45 minutes, touch-dry in ~65 minutes and walkable in just 5 hours. Full cure in 24 hours.

The ARGYNET View:

Two things set this material apart from other polyurethanes in the same category.

The first is time. Walkable in 5 hours and fully cured in 24 means that a flat roof can be started and completed within the same two-day period. With a 1K polyurethane, it takes 2–5 days to reach final strength. On a project with a penalty clause or in a hotel due to open, this difference is the deciding factor.

The second factor is the cost: a working time of 45 minutes. The material is mixed in a 70:30 ratio, stirred mechanically for 3 minutes, and from then on the clock is ticking. This is not a material for a contractor crew learning on the job — it requires planning of quantities per mix.

And one distinction that must be made clear: FC/A indicates no change in properties after 2,000 hours of accelerated ageing (ASTM D 4587). However, it does not indicate colour stability — unlike the aliphatic ISOPLAST FC and FC/TR, which explicitly state that they do not yellow. Where appearance is important, FC/A is used as the base coat and the aliphatic product as the top coat.