One, Measurement Calculation and Design: Determine the location, elevation, and slope of the drainage channel. Specify the cross-sectional dimensions of the drainage channel as 300*150mm, and the PC drainage channel dimensions as 770*200*20mm.

Excavation and Construction of Drainage Channels: Moisten the base surface of the drainage channel with water, then use string lines to find the slope according to the slope requirements of the drainage channel, and create reinforcement at 2m intervals. Once the reinforcement reaches the required strength, lay cement mortar in the sections, smooth it with a scraper against the reinforcement, and then finish the slope with an iron trowel.

Prior to laying the drainage trench PC, moisten the ground and top surface of the drainage trench with water. Then, use a string to control the elevation of the trench. After dry-laying cement mortar, proceed to lay the drainage trench PC. Ensure that the mortar on the outer side of the trench is tightly packed to prevent the PC from hollowing, thereby guaranteeing a tight fit between the drainage trenches.

Upon reaching the required strength, water the bottom of the drainage trench to moisten the slope layer. After drying the bottom with cement mortar, lay 300*600mm tiles. Pay attention to controlling the slope of the trench bottom and the gaps between the tiles during the laying process.

Roof Tile Installation and Joints: At the intersection of tiles and drainage channels, and every 6 meters of tile installation, a 20mm wide joint is set. Use plywood for the joints and secure them firmly with cement mortar. Install the roof tiles in sections according to the joints, chisel and clean the joints of the plywood, and fill the gaps with asphalt paste.

The roof drainage channel PC construction has been completed.