What are best practices for joint sealing in metal façades?

Effective joint sealing is critical to preventing water infiltration and accommodating thermal movement in aluminum façades. Designers specify durable silicone or polysulfide sealants compatible with metal substrates and engineered for UV stability. Butt joints often include back-route tapes or compressible closed-cell foam to control sealant depth and optimize seal geometry. Horizontal joints should slope slightly outward to shed water, and vertical joints rely on proper substrate priming to ensure bond strength. Installers apply sealant using static-mix nozzle cartridges to avoid air entrapment, tooling the bead to a concave profile that promotes self-cleaning. Expansion joints—placed at intervals based on panel width and expected temperature ranges—allow ±5 % movement without stress. Adhering to manufacturer cure-time guidelines and environmental conditions ensures reliable, weathertight seals over the life of the façade.