sellante

Sellante is a material used to seal joints and gaps, preventing the passage of air, water, and dust, while accommodating substrate movement. It adheres to many common construction materials such as concrete, glass, metal, wood, and ceramic, and is distinguished from adhesives by its primary sealing function rather than bonding strength. However, many sealants also offer bonding.

Types include silicone sealants (moisture-curing; neutral-cure or acetoxy), polyurethane sealants, polysulfide sealants, acrylic latex sealants, and bituminous sealants. Silicone sealants are highly resistant to weathering and temperature, while acrylics are easier to apply and paintable; polyurethanes provide good adhesion and durability but may require primers on some substrates.

Applications include window and door frames (glazing joints), bathroom and kitchen joints, expansion joints in façades, roofs and gutters, as well as automotive and industrial sealing. They are sold in cartridges or tubes and applied with a caulking gun. Curing depends on formulation: moisture-curing silicones cure through ambient humidity; others cure chemically or by evaporation, with cure times ranging from hours to several days.

Key properties to consider when selecting a sealant include elasticity (shrinkage and recovery), adhesion to substrates, chemical and UV resistance, temperature range, durability, and, for some types, paintability. Performance is specified by standards such as EN 15651 and ISO 11600, which classify sealants by movement capability and use.

Safety considerations include the presence of solvents or VOCs in some formulations; use in well-ventilated areas and follow manufacturer recommendations for protective gear and disposal.