The Everbuild 203 Accelerator & Frostproofer is a powerful liquid additive for mortar, concrete, screeds and rendering that helps to both accelerate their setting and hardening times and also provide improved frost protection in cold weather. The ideal choice for a cold weather admixture, this Accelerator & Frostproofer can be used in sub-zero temperatures and features a chloride-free, non-corrosive formula.