Rigid waterproofing and flexible waterproofing are two ways of building waterproofing. Rigid waterproofing is achieved through the compactness of structural components or the use of rigid materials as waterproof layers to achieve the waterproofing purpose of buildings. Flexible waterproofing blocks the passage of water through flexible waterproofing materials such as waterproofing membranes and waterproof coatings to achieve the purpose of building waterproofing.

1. Rigid waterproofing

(1) Rigid waterproof form

"Rigid" means "hard and not easy to change". Rigid waterproof is mainly made of cement, sand and stone, mixed with a small amount of additives or synthetic polymer materials to form a rigid object of cement gel. Generally, it can include three forms:

(1.1.1) Self waterproofing of concrete structures: Using waterproof concrete as the structural concrete material, the structural concrete components have strong anti-seepage ability to prevent water infiltration.

Waterproof concrete is the basic material for self waterproofing of concrete structures. In addition, the use of cement-based or liquid permeable crystalline waterproof materials to improve the impermeability of structural concrete and form structural self waterproofing can also be classified as this type of form.

(1.1.2) Rigid waterproof coating: A rigid coating with impermeability is formed on the surface of ordinary concrete or masonry substrates to prevent water infiltration, among which mortar waterproof layer is the most widely used. Other coatings include those formed by resins, modified cement, etc.

(1.1.3) Rigid body waterproofing is formed by grouting and plugging defects in structural nodes and self waterproofing structures using special cement, hydrogen curing, propylene curing and other materials.

(2) The advantages of rigid waterproofing

(1.2.1) It has high compressive strength, tensile strength, and a certain degree of impermeability, and can be used for both waterproofing and load-bearing, enclosure, and other functions.

(1.2.2) Strong aging resistance and long durability.

(1.2.3) Materials are readily available, cost-effective, and easy to construct.

(1.2.4) Easy to locate leakage points and facilitate repairs.

(1.2.5) Generally, it is an inorganic material that is non combustible, non-toxic, and odorless.

(3) Disadvantages of rigid waterproofing

(1.3.1) Generally, inorganic rigid materials will experience certain volume shrinkage during the curing process, which can lead to cracks in the rigid waterproof layer under external constraints, resulting in waterproof failure.

(1.3.2) Strong sensitivity to various deformations. Ground or foundation settlement, structural stress deformation, and temperature deformation caused by thermal expansion and contraction can all pose significant hazards to the rigid waterproof layer, leading to cracks and waterproof failure.

2. Flexible waterproofing

Flexible waterproofing is a form of waterproofing that is opposite to rigid waterproofing. It is achieved by blocking the passage of water through flexible waterproofing materials such as waterproofing membranes and waterproof coatings, in order to achieve the purpose of building waterproofing.

(1) Flexible waterproof form

According to the appearance of flexible waterproof materials, flexible waterproofing can be divided into three categories: roll waterproofing, coating waterproofing, and sealing waterproofing.

(2.1.1) Connect the waterproof roll material into a whole waterproof layer by bonding, welding, etc., to achieve the purpose of waterproofing. Waterproof roll refers to a curled sheet waterproof material made in a factory using specific production processes. Due to the mechanized production of waterproofing membranes in factories, the production conditions and factors affecting product quality can be well controlled, resulting in good stability of product quality. Compared with waterproof coatings, its thickness is uniform and easy to control, making it the mainstream product in waterproof materials. However, due to the limitation of the width of the waterproofing membrane, it is necessary to use overlapping construction in waterproofing projects. If the construction is not handled properly, defects such as warping, wrinkling, and poor sealing may occur, resulting in quality problems such as water leakage.

(2.1.2) Coating waterproofing refers to applying waterproof coating to the surface of the substrate, and after the coating is cured, forming a complete coating waterproof layer to achieve the purpose of waterproofing. Waterproof coating refers to a coating that is a viscous liquid at room temperature, applied or sprayed onto a substrate using tools such as brushes, rollers, scrapers, and spray guns. After solvent (water) evaporation or reaction curing, the coating has waterproof and anti-seepage functions. Compared with roll materials, the overall integrity of the coating waterproof layer is good, the waterproof coating is easy to apply, and it has strong adaptability to irregular base layers and complex node areas. However, the material uniformity and thickness uniformity of the coating waterproof layer are not as good as those of the roll waterproof layer.

(2.1.3) Sealed waterproofing refers to filling sealing materials at nodes or rigid waterproof joints to block the passage of water and achieve the purpose of waterproofing. Sealing materials refer to both fixed and non fixed materials that can withstand displacement and have high air and water tightness, and are embedded in building joints. The standardized sealing material is generally referred to as a sealing strip or sealing tape; Unshaped sealing materials are generally referred to as sealant or sealant.

(2) The advantages of flexible waterproofing

(2.2.1) The overall integrity of the membrane waterproof layer and the coating waterproof layer is good. Strong waterproof ability and high reliability.

(2.2.2) It has good ductility and flexibility, and has strong adaptability to deformation and cracking of the base layer.

(2.2.3) The flexible waterproof layer is lightweight and easy to adhere to the surface of the base layer.

(3) Disadvantages of flexible waterproofing

(2.3.1) It is susceptible to the effects of ultraviolet radiation, ozone, high temperature, etc., and its aging resistance and durability are not as good as rigid waterproofing.

(2.3.2) The puncture resistance is not as good as rigid waterproofing, and it is more prone to damage when punctured or pulled by external forces.

(2.3.3) High requirements for the quality of the base surface, requiring a flat and clean base layer. Most flexible materials require a dry base surface.