Closed-cell spray foam insulation

Spray polyurethane foam (SPF) is a rigid or semi-rigid PU foam applied in situ by high-pressure spray equipment directly on the substrate to be insulated. Unlike panels or injection foam, spray foam does not come in a pre-defined shape — it adapts to the geometry of the surface, penetrating cavities, adhering to pipes, conforming to irregularities. This is its main commercial differentiator.

There are two basic families: closed-cell spray foam (density 30–45 kg/m³, closed-cell content above 90%, lambda around 0.020 W/m·K) and open-cell spray foam (density 8–15 kg/m³, open cell, lambda around 0.035–0.040 W/m·K). Closed-cell is superior for thermal insulation, moisture barrier and structural integrity; open-cell is cheaper, acoustically more absorbent, but does not block water vapor and does not work well on exposed applications.

Closed-cell spray foam is applied in layers of 25–50 mm per pass; multiple passes allow total thicknesses of up to 200 mm in a single application. The system cures in seconds after contact with the substrate, forming a continuous insulation layer without joints. Main applications: building envelopes (walls, roofs, attics), industrial insulation (tanks, ducts, pipe systems), specific automotive/marine/aerospace applications, roof retrofit on existing industrial buildings.