How to Make Prefabricated House Finished Stairs

The production and installation of prefabricated house finished stairs should follow a standardized process, with the specific steps as follows:

1. Construction Preparation
Lay a 20-millimeter-thick layer of C20 fine aggregate concrete mortar at the upper and lower openings of the stair stringers for leveling, ensuring that the flatness error of the base layer does not exceed 3 millimeters. Alternatively, set out the positioning lines for the prefabricated stair sections according to the design positioning axes and perform secondary leveling with M20 cement mortar at the locations of the cast-in-place corbels. This step provides an accurate reference surface for subsequent hoisting and prevents installation deviations of components due to an uneven base layer.

2. Inspection Before Hoisting
Double-check the quality of the components: First, verify that the number of the prefabricated stairs matches the construction drawings to avoid incorrect installation. Second, inspect the appearance of the components through visual observation and instruments, focusing on checking for defects such as cracks and honeycombing. At the same time, confirm that the embedded lifting rings, connectors, and other metal parts are free from rust or deformation. Before hoisting, adjust the posture of the stairs to ensure that their center of gravity coincides with the centerline of the lifting equipment, preventing tilting during the hoisting process.

3. Hoisting Operation
Use large lifting equipment such as tower cranes or truck cranes, along with dedicated steel wire rope lifting fixtures, for the operation. The lifting fixtures should be firmly connected to the embedded lifting points of the stairs through universal swivel rings to ensure that the lifting ropes are vertically stressed. When hoisting, slowly lift the component to a height of 500 millimeters above the ground, hover for 2 minutes to observe the stability of the lifting fixtures, and then run it evenly to a position 1 meter above the operating surface and pause to avoid impact damage caused by rapid descent.

4. Positioning and Adjustment
After the component is basically in place, use a crowbar to make fine horizontal adjustments to the stairs so that the deviation between their edges and the positioning lines is controlled within ±2 millimeters. The operators should hold the stairs steadily with both hands and guide the component to descend slowly along the control lines with the help of a laser level, until the lower end of the stairs is in full contact with the surface of the stair stringers. Rough pushing or bumping is strictly prohibited during this process.

5. Alignment and Hook Removal
Use a total station to recheck the elevation, axis position, and perpendicularity of the stairs to ensure that all deviations meet the specification requirements (elevation deviation ≤ 3 millimeters, perpendicularity deviation ≤ 2 millimeters). After alignment is completed, slowly loosen the lifting ropes and remove the universal swivel rings. During hook removal, have a dedicated person on guard to prevent sudden displacement of the component.

6. Fixing and Finished Product Protection
Use high-strength non-shrink grout to inject and fix the joints between the stairs and the stair stringers. The thickness of the grout layer should meet the design requirements and have a flat surface. After grouting is completed, cover the surface with plastic film for curing for 3 days, during which stepping or stacking of heavy objects is prohibited. Lay wooden formwork or rubber mats on the surface of the stairs for protection, and stick corner protectors at the corners to avoid impact damage during subsequent construction.