Soudal Fixall Flexi

Soudal Fixall Flexi is a one-part hybrid polymer adhesive sealant that combines the flexibility of silicone with the bonding strength of polyurethane. It cures chemically, contains no solvents, and is practically odourless, which is always welcome when you are working inside someone’s kitchen or bathroom. The result is a tough, flexible bond that handles movement, vibration and weathering without cracking or pulling away from the substrate.

What makes Fixall Flexi genuinely useful on site is the primerless adhesion. It grabs directly onto most construction materials, including wet and damp surfaces, which removes the waiting, the prep work and the inevitable disappearing act of the primer brush. Wood, metal, glass, concrete, stone, ceramic, PVC, most plastics — it sticks. The exceptions are PE, PP and PTFE, which nothing sticks to without specialist prep, so no surprises there.

Where Soudal Fixall Flexi Works Hardest

As a sealant it performs equally well, with the added benefit of XS1 fungicide technology built in, giving it strong mould resistance over time. That makes it a sensible choice for wet areas, external joints, window surrounds and anywhere moisture tends to linger and cause problems down the line. The flexibility is particularly useful for joints that are likely to move, whether that is thermal expansion in external cladding or the usual subtle settlement you see in older buildings.

Soudal Fixall Flexi is available in White, Grey, Brown, Black and Crystal Clear, so you can match it to the job rather than painting over a mismatch. It can be overpainted once cured, which adds another layer of finish options. Weather conditions are not a concern either — it applies in wet weather and cures reliably without needing a dry window that never seems to arrive on UK sites.