The Sika®1 Waterproofer delivers advanced protection for below-ground structural screeds and above-ground waterproof renders through proven colloidal silicate technology. This aqueous solution creates lasting barriers against moisture intrusion in sand/cement applications. The formulation contains complex colloidal silicates that swell and block capillaries and pores within renders, screeds and mortar. This mechanism forms a formidable barrier against liquid water transmission, ensuring robust waterproofing performance across demanding construction environments. With over 100 years of proven reliability, this ready-to-use solution offers excellent resistance to backwater pressure and chloride-free composition. Suitable for brick, concrete and stone substrates, it performs across both internal and external applications, including use against live water infiltration when combined with Sika® 2 and Sika® 4A. Features & Benefits: Proven waterproofing performance with over 100 years of field-tested reliability. Advanced colloidal silicate technology blocking capillaries and pores for superior moisture protection. Excellent resistance to backwater pressure in demanding below-ground and above-ground applications. Compatible with brick, concrete and stone substrates for multiple installation options. Suitable for internal and external wall render and floor screed applications. Can be applied against live water infiltration when used in conjunction with Sika® 2 and Sika® 4A. Chloride-free formulation protecting against corrosion in reinforced structures. Ready-to-use solution requiring no mixing or preparation. Colour: Yellow. Pack Size: 5ltr.