Fire Protection - Intumescent Painting

We were instructed by a client to attend 21 Bloomsbury street London. We sand blasted all the steelwork throughout the entire building. 7 floors and atrium area to remove all the old vermiculite and coatings back to S.A.2.5. Finish. We then airless sprayed Sherwin Williams primer to protect the steels. We then airless sprayed with intumescent paint to achieve a minimum 90-minute fire protection to finish.