Waterproofing for Rural Prefabricated House Assembly

For the waterproofing of rural prefabricated house assembly, special attention should be paid to the treatment of joint seams. Waterproof materials should be selected according to the characteristics of different areas and construction should be carried out in a standardized manner.

Roof Waterproofing

The joint seams of prefabricated floor slabs are about 2-3cm wide and are weak points for waterproofing. It is recommended to use 4mm-thick SBS modified bitumen waterproof membranes, which have excellent resistance to high and low temperatures, flexibility, and abrasion resistance, making them suitable for rural roof environments. The joint seams should be reinforced with self-adhesive waterproof membranes to form a double-layer protection. In addition, the roof has a small drainage slope (about 2%), which is prone to water accumulation. It is necessary to enhance the impermeability by increasing the thickness of the waterproof layer or applying waterproof coatings to avoid long-term water accumulation leading to leakage.

Exterior Wall Waterproofing

Weak points on exterior walls include joint seams of prefabricated wall panels, the perimeters of door and window openings, and the roots of pipes passing through the walls. It is advisable to use polymer cement-based waterproof coatings (Type II), which have strong adhesion, good flexibility, can be applied on damp substrates, and have excellent weather resistance. During construction, it is necessary to use exterior wall waterproof putty to fill the gaps and seal the perimeters of door and window openings and pipe roots with sealants to form a complete waterproof layer.

Kitchen and Bathroom Waterproofing

Joint seams of prefabricated floor slabs, areas where pipes pass through the floor, and internal and external corners are high-risk areas for leakage. It is recommended to use polyurethane waterproof coatings (Type I), which have high elongation and strong impermeability, making them suitable for humid environments. During construction, fiberglass mesh should be laid at the joint seams and internal and external corners to reinforce and form a flexible waterproof layer, preventing cracking due to structural deformation.

Basement Waterproofing (Partial)

Semi-underground structures are constantly humid, and groundwater can easily seep in through joint seams of prefabricated panels and concrete cracks. It is necessary to adopt dual protection of structural self-waterproofing and external waterproof layers: Structural self-waterproofing is achieved by improving the density of the concrete; the external waterproof layer should focus on treating areas such as the junctions between the floor and wall panels and bolt holes passing through the walls. Polymer cement-based waterproof coatings or membranes can be used, and water stops or hydrophilic water stop strips should be installed.

Key Points for Construction Preparation

1. Technical Disclosure: Organize construction personnel to familiarize themselves with the drawings, clarify the requirements for waterproof areas, technical standards, and quality control points, and conduct special disclosures according to the structural characteristics of the prefabricated houses.
2. Weather Control: Obtain weather forecasts in advance during the construction period and avoid outdoor waterproofing operations on rainy, snowy days, or when there is wind of force 5 or above to prevent rainwater from washing away or strong winds from damaging the uncured waterproof layer.