TECHSEAL PU 1 is a novel low modulus expansion joint sealant, specially formulated to contain both PU and silylated – PU technology, thus giving rise to a sealant that includes the best of both technologies. TECHSEAL PU 1 cures by reaction with atmospheric humidity to produce a joint sealant with a ± 25% joint movement accommodation factor, which has excellent adhesion on substrates traditionally problematic for PU sealants, e.g. glass, aluminum, steel, polycarbonate, etc. Additionally, the sealant has been modified in order to have an extrusion profile identical to hybrid PU or MS technology. The extrusion rate and tooling of the sealant remain the same throughout a very wide range of temperature and humidity conditions. The sealant is easy to apply even in very low temperatures and the storage stability is unlike any polyurethane sealant in the market.