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 waterproof is to prevent water from penetrating into some parts of the building and measures taken from the building materials and structure. Waterproof is mostly used in roof, underground building, underground part of building, inner room and water storage structure. According to the different measures and means, it can be divided into two categories: material waterproofing and structural waterproofing. Material waterproofing is to block the water passage by building materials to achieve the purpose of waterproof or increase the ability of anti leakage, such as membrane waterproofing, membrane waterproofing, rigid waterproofing of concrete and cement mortar, clay and lime soil waterproofing, etc.
构造防水则是采取合适的构造形式，阻断水的通路，以达到防水的目的，如止水带和空腔构造等。 主要应用领域包括房屋建筑的屋面、地下、外墙和室内；城市道路桥梁和地下空间等市政工程；高速公路和高速铁路的桥梁、隧道；地下铁道等交通工程；引水渠、水库、坝体、水利发电站及水处理等水利工程，等等。随着社会的进步和建筑技术的发展，建筑防水材料的应用还会向更多领域延伸。
Structural waterproofing is to take appropriate structural forms to block the water passage, so as to achieve the purpose of waterproof, such as water stop belt and cavity structure. The main application fields include roof, underground, external wall and interior of housing construction; municipal engineering such as urban road and bridge and underground space; bridge and tunnel of Expressway and high-speed railway; traffic engineering such as subway; water conservancy project such as diversion canal, reservoir, dam body, water power station and water treatment, etc. With the progress of society and the development of building technology, the application of building waterproof materials will extend to more fields.