How to Make a Drainage Ditch for a Prefabricated House

The production of drainage ditches for prefabricated houses requires selecting a plan based on the scenario. Here are common methods and steps:

I. Cast-in-place Concrete Drainage Ditch (Suitable for rural yards and other scenarios)

1. Measurement and Planning
   • Use a tape measure to measure the slope of the yard, ensuring a drop of 2-3 centimeters per meter for smooth drainage. Design the direction according to the shape of the yard, using 45-degree elbows at corners and tees at intersections, avoiding key structures such as foundations and corners.
2. Materials and Construction
   • Prefer cast-in-place concrete with a strength of C30 or higher, which is cost-effective and fits the ground well, with no issues for normal use over 20 years. Use a vibrating rod to compact the concrete during construction and roughen the surface for slip resistance.
   • Apply 2-3 coats of polyurethane waterproof coating to the ditch bottom and lay a 10-centimeter-thick crushed stone bedding layer; round the ditch edges to avoid sharp corners; make the drainage outlet 2-3 centimeters lower than the main ditch and install a cast-iron cover with a filter screen.
3. Acceptance
   • After completion, conduct a 24-hour water storage test to check for leakage.

II. Prefabricated U-shaped Trough Drainage Ditch (Suitable for municipal, residential, and other engineering scenarios)

1. Construction Preparation
   • Conduct on-site surveys according to the design drawings to determine the specifications of the U-shaped trough (e.g., depth of 30 cm, top width of 40 cm) and slope (0.5%-1%). Check the dimensional deviation, surface flatness, and compressive strength of the troughs and send samples for inspection.
2. Foundation Trench Treatment
   • Excavate the foundation trench with an excavator, reserving 10-15 cm for manual trimming. The trench bottom must be flat and solid. For soft soil foundations, backfill with graded sand and gravel and compact in layers, with a compaction degree of no less than 93%.
3. Laying and Connection
   • After wetting the trench bottom, place the U-shaped troughs and level them with a level gauge. Connect adjacent troughs with tongue-and-groove joints and apply sealant. Set up concrete piers every 3-5 meters and cut and customize curved troughs at turns.
   • Backfill the gaps between the trench bottom and slopes with medium-coarse sand and pour C25 concrete covers on the trench top, leaving a 5 mm gap.
4. Acceptance Criteria
   • Check the appearance (neat arrangement, tight joints), dimensions (axial deviation ≤ 10 mm), and drainage performance (no water accumulation in simulated rainfall tests).

III. Simple PVC Pipe Drainage Ditch (Suitable for low-cost DIY scenarios)

• Cut a 110 mm PVC pipe in half and lay it at the bottom of the drainage ditch, securing it with cement around it. Use tile strips at the junction of the lawn and the drainage ditch to block soil, and the grass will cover the edges when it grows tall. This plan is cost-effective (material cost about over 1000 yuan) but requires self-construction.

Plan Selection Suggestions: For engineering scenarios, prefabricated U-shaped troughs are recommended; for rural yards, cast-in-place concrete can be chosen; for low-cost DIY, the PVC pipe plan can be tried.