建筑防水即为防止水对建筑物某些部位的渗透而从建筑材料上和构造上所采取的措施。防水多使用在屋面、地下建筑、建筑物的地下部分和需防水的内室和储水构筑物等。按其采取的措施和手段的不同，分为材料防水和构造防水两大类。材料防水是靠建筑材料阻断水的通路，以达到防水的目的或增加抗渗漏的能力，如卷材防水、涂膜防水、混凝土及水泥砂浆刚性防水以及粘土、灰土类防水等。
Building waterproofing is a measure taken from building materials and structures to prevent water from permeating into some parts of the building. Waterproofing is mostly used in roofs, underground buildings, underground parts of buildings, interior rooms and water storage structures that need waterproofing. According to the different measures and means, it can be divided into material waterproof and structural waterproof. Material waterproof is to block the passage of water by building materials, so as to achieve the purpose of waterproof or increase the ability of anti leakage, such as membrane waterproof, membrane waterproof, concrete and cement mortar rigid waterproof, clay and lime soil waterproof, etc.