Water Seepage on the Exterior of Cement Prefabricated Houses
The following methods can be used to address water seepage on the exterior of cement prefabricated houses:
Crack Repair
If water seepage is caused by cracks, first groove the cracks to a depth that exposes the wall base. Fill the cracks with cement mortar and level them. After drying, apply mesh fabric to enhance crack resistance. Reapply waterproof coating in the weak areas of the waterproof layer (such as around the cracks) in two coats. Wait for the first coat to dry completely before applying the second coat to ensure a continuous and complete waterproof layer.
Use of Penetrating Waterproofing Agents
For water seepage caused by small cracks in the exterior wall, penetrating waterproofing agents are an effective choice. Spray the waterproofing agent evenly on the seepage area. Multiple applications are required to form a complete waterproof layer. The waterproofing agent will gradually penetrate into the concrete, react with the alkaline substances in the cement mortar to form crystals, fill the capillaries and cracks, and block the water seepage channels from the inside.
Waterproofing Redo
If the exterior wall has severe leakage and the seepage points are scattered, there is no need to locate each point individually. Instead, the entire waterproof layer can be redone. First, remove the original waterproof layer, repair all leakage points, and then lay new waterproof materials (such as waterproof membranes or coatings) comprehensively to form a continuous waterproof barrier.
Waterproof Coating Application after Cleaning
Thoroughly clean the dirt and loose materials from the leakage area to ensure the base is dry and level. Apply waterproof coating to form a new waterproof layer. Cover the leakage area and a surrounding range of 20-30 centimeters. After the waterproof layer dries, apply a layer of cement mortar as a protective layer to prevent damage to the waterproof layer.
Sealing Treatment
For larger cracks or obvious seepage points, materials such as silicone sealants or polyurethane sealants can be used. Clean the wall and keep it dry before construction to ensure the sealant can adhere fully. Fill the sealant deep into the cracks and level the surface to avoid leaving pores.
Exterior Wall Coating Treatment
Select special exterior wall coatings with waterproof functions, which form a dense waterproof film after application. The coatings should have weather resistance and anti-aging capabilities to adapt to outdoor environments. Choose appropriate coatings based on the wall materials (such as concrete or brick walls) and environmental conditions (such as humidity and temperature), and follow the manufacturer's instructions strictly during construction.
Improvement of Drainage System
Check whether the rain gutters, drainage pipes, and sewers are unobstructed, and clear any blockages promptly. Ensure the roof drainage slope is reasonable so that rainwater can quickly drain away from the wall, avoiding water accumulation on the wall surface that could lead to seepage.
Strengthening of Base Treatment
Thoroughly clean the wall before construction to remove oil stains, dust, and other impurities. Ensure the base is dry, level, and solid. For old walls, roughening and slurry application treatments can be carried out to increase the wall roughness and improve the adhesion between the waterproof material and the base.
Wall Insulation and Heat Insulation
Installing insulation materials (such as polystyrene boards or rock wool boards) can improve the wall's insulation performance and reduce the formation of condensation water caused by temperature differences. At the same time, the insulation layer can enhance the wall's integrity and reduce the risk of water penetration. During construction, ensure the insulation materials are tightly attached to the wall to avoid leaving gaps.
