ARDEX S 21 is a high-performance, fast-setting cementitious adhesive classified under the BS EN 12004 C1 F standard. This designation indicates that the adhesive is designed for quick setting and is ideal for situations where time is a factor. Once tiles are set with ARDEX S 21, they can be grouted and subjected to normal use within just 3 hours at standard temperatures. This makes it particularly useful for projects that require rapid turnaround or for environments where lower temperatures could slow down the setting of traditional cement-based adhesives. ARDEX S 21 is a grey pow