With the Teifoc supplementary Cement Mortar packs you can build every Teifoc model again and again Teifoc is a unique build and play system that uses real bricks to create fun and elaborate structures and creations. The cement is safe and soluble in water so that the bricks can be reused again and again. The Cement bag gives you extra mixing cement so you can continue to create your marvelous structures Teifoc is totally safe and adequate for children. To dissolve the cement, leave the building in water for 2 hours. Then rinse the bricks, leave them to dry, and start all over again using new cement.