How to Make Eaves for a Prefabricated Cement House

The construction of eaves for a prefabricated cement house should follow the steps below to ensure waterproofing and structural stability:

1. Template Positioning and Fixing

Determine the position of the drip edge on the eaves according to the design drawings (2-3 centimeters from the outer edge). Use steel nails or wire ties to firmly fix the PVC eagle-beak drip edge or fiberglass material to the template, ensuring the line is straight and parallel to the edge of the eaves. The template should be tightly joined to prevent slurry leakage, while also reserving space for concrete vibration.

2. Cement Mortar Pouring

• Material Mixing Ratio: Mix the cement mortar according to the design strength requirements, controlling the water-cement ratio to avoid excessive dilution, which can lead to insufficient strength.
• Pouring Points: Pour the mortar evenly into the template, and use a trowel or scraper to level it in layers. The thickness should meet the design requirements (usually 8-12 centimeters). During vibration, avoid direct contact between the vibrating rod and the drip edge to prevent displacement or damage.
• Flatness Control: After pouring, use a 2-meter level to check the surface flatness, with an error not exceeding 5 millimeters.

3. Curing and Form Removal

• Curing: After pouring, cover the surface with plastic film or straw mats, and regularly sprinkle water to keep it moist. The curing time should be no less than 7 days to prevent the concrete from cracking due to rapid drying.
• Form Removal: After the concrete reaches the design strength (usually 24-72 hours), carefully remove the template to avoid damaging the edge of the eaves. After form removal, check if the drip edge is firmly embedded; if it is loose, reprocess it.

4. Drip Edge Treatment

• Pre-embedded Molding Method: Pre-embed PVC or fiberglass drip edges during the template stage. After form removal, a convex line with an inner-high and outer-low profile (depth and width ≥ 10 millimeters) is formed, which disrupts the surface tension of the water flow and prevents rainwater from flowing backward.
• Post-installed Method: If not pre-embedded, clean the floating dust at the bottom of the eaves, mark the position with a chalk line, and then adhere the drip edge with structural adhesive or fix it with expansion screws to ensure firm bonding.

5. Waterproofing and End Treatment

• Roll Waterproofing: The roll material within 800 millimeters of the eaves should be fully adhered, and the end should be fixed with metal strips and nails, and sealed tightly with sealing material.
• Coating Waterproofing: Apply multiple coats of waterproofing paint at the end to enhance erosion resistance.
• End Treatment: Apply polymer cement mortar at the end of the eaves, and create an eagle-beak or drip groove at the lower end to guide rainwater away from the wall.

6. Quality Inspection

• Appearance Inspection: The surface of the eaves should be flat, without honeycombs, pits, cracks, or other defects.
• Dimensional Deviation: Use a steel ruler to check the thickness and width of the eaves, with an error not exceeding ±5% of the design value.
• Drip Edge Straightness: Check with a straight line, with a deviation not exceeding 3 millimeters.
• Leakage Test: Check for no water accumulation or leakage after rain or a water spraying test.

Precautions:

• The drip edge must be inner-high and outer-low, with a depth and width that meet the specifications (≥ 10 millimeters).
• During curing, avoid stepping on or placing heavy objects on the surface to prevent structural damage.
• When trimming the edge after form removal, maintain the integrity of the eagle-beak shape of the drip edge to ensure drainage function.