How to Construct the Roof of a Prefabricated House
The construction of the roof of a prefabricated house involves sequential steps including waterproofing, roofing, insulation, and selection of decoration styles and materials. Here are the specific operations:
I. Waterproofing Treatment
Waterproofing is a core aspect of roof construction, directly affecting the service life of the house. 1. Base Treatment: Thoroughly clean the surface of the prefabricated roof, removing dust, sand, and debris to ensure a flat base. If there are cracks or defects, fill them with cement mortar or specialized repair materials to prevent subsequent cracking of the waterproof layer. 2. Application of Waterproof Coating: Select an appropriate waterproof coating (such as polyurethane or acrylic) according to the product instructions. Apply evenly using a roller or spray equipment. Apply 2-3 coats, with intervals between each coat as specified by the manufacturer, ensuring the coating thickness meets standards and there are no omissions. 3. Installation of Waterproof Membrane: After the coating dries, choose SBS modified bitumen membrane or polymer membrane based on the roof slope. Install from the lower to the higher part, with an overlap width of no less than 10 cm between membranes. Seal the joints with hot melting or adhesive methods to prevent water infiltration. 4. Water Closure Test: After completing the waterproof layer, close all drainage outlets, fill with water to a depth of about 5 cm, and maintain for more than 24 hours. Observe for any leakage on the roof and walls. If issues are found, repair locally and retest. 5. Protective Layer Construction: After passing the water closure test, install a protective layer of mortar (2-3 cm thick) or fine aggregate concrete (4-5 cm thick) to protect the waterproof layer from UV rays or external forces, extending its service life.
II. Roofing Installation
1. Material Selection: Choose materials such as waterproof blankets, clay tiles, asphalt shingles, or metal roofing panels based on design requirements. For example, flat roofs can use waterproof blankets to enhance sealing, while pitched roofs are suitable for tile materials. 2. Measurement and Design: Accurately measure the roof dimensions, calculate material quantities, and determine the slope (generally 2%-5%) and drainage direction to avoid water accumulation. Design with provisions for inspection hatches or ventilation openings. 3. Installation Points: Install from bottom to top and left to right, ensuring tight material joints. Tile materials should be staggered and overlapped, while metal panels should be fixed with specialized screws to prevent wind uplift.
III. Insulation Treatment
1. Insulation Material Selection: Prioritize materials with low thermal conductivity and good flame retardancy, such as extruded polystyrene (XPS, thermal conductivity ≤ 0.03 W/m·K), EPS boards, or rock wool boards. In humid areas, choose hydrophobic materials. 2. Insulation Installation: Install insulation boards below the waterproof layer or roofing layer, using spot or full adhesion methods for fixation. Fill board joints with expanding foam. If the roof is already installed, add insulation cotton to the indoor ceiling to enhance thermal insulation.
IV. Decoration Style and Material Selection
1. Decoration Style: Choose styles such as minimalist (focusing on lines and functionality), modern (integrating metal and glass elements), European (emphasizing carvings and arch designs), or Chinese (using wood and symmetrical layouts) based on personal preference. 2. Material Selection: For the roof floor, choose non-slip tiles, anti-corrosion wood, or stone. For wall decoration, select lightweight partition boards or waterproof coatings. Materials should balance weather resistance and aesthetics, such as outdoor wood requiring anti-corrosion treatment.
