1. Dig beam groove first, lay bricks, film, plaster to smooth the surface, make SBC 120 waterproof, make cement mortar protective layer after 30 days, tie steel bars after the strength of protective layer meets the requirements, and pour concrete foundation slab. 2. Generally, there is no waterproof requirement for cushion, but there is waterproof requirement for basement concrete. Most basement concrete is added with silica thickener or concrete expansion agent.