One-component thixotropic polymer-modified cementitious coating, waterproof, formulated with amorphous microsilicas with high pozzolanic reactivity, specific anti-corrosion inhibitors and suitable additives that give the product the consistency of a brushable gel with high covering power and very high adhesion to metal reinforcements, ensuring an effective and lasting barrier against corrosion. Product complies with the principles of EN 1504-9 “Products and systems for the protection and repair of concrete structures: definitions, requirements, quality control and conformity assessment. General principles for the use of products and systems” meeting the requirements of active coating and barrier against corrosion of steel reinforcements in accordance with EN 1504-7 “Corrosion protection of reinforcements”.