Dig a trench from the place in your yard that needs drainage to your chosen outlet. Check for underground utility lines and pipes before digging. The trench should be about 18 inches deep and 9 to 12 inches wide. least 1 percent, so the force of gravity will work for you.
For instance, a 4-inch pipe for a French drain should be installed in a trench 6-12 inches wide and 18-24 inches deep.
We recommend digging it about one foot wide and 18 inches deep. The wider the trench, the easier it is to collect water and the lower the chance of clogging. Your trench needs to be lined with water-permeable landscaping fabric in order to prevent damage caused by grass and plant roots.
A trench is defined as a narrow excavation (in relation to its length) made below the surface of the ground. In general, the depth of a trench is greater than its width, but the width of a trench (measured at the bottom) is not greater than 15 feet (4.6 m). What are the dangers of trenching and excavation operations?
The minimum cover required when the drainage system is in a traffic area with drainage pipe diameters from 100 mm through 1200 mm (4”-48”) must have at least 0.3 m (12”) of cover over the pipe crown, while 1500 mm (60”) pipes must have at least 0.6 m (24”) of cover.
All drainage pipes should be placed on the gravel bed in the trench. PVC drainpipe, if used, should be placed in the trench with the holes facing down.
Pipe for conveying liquids susceptible to freezing should be buried no less than 12" below the maximum frost level. Permanent lines subject to heavy traffic should have a minimum cover of 24". For light traffic, 12" to 18" is normally sufficient for small diameter pipe (typically < 3" diameter).
5 feet deep trenches must have a protective system in place. Trenches greater than 4 feet must have a ladder for exit and egress. Ladders should extend at least 3 feet from the excavation for easy access and easy exit. Place excavated materials 2 feet away from the edge of the excavation.
Common widths are 5", 6", 8", and 12". Wider channels increase flow rates and can handle more water. Thus, channel widths of 5-8" are generally sufficient for moderate pooling. Twelve-inch channels are better suited for areas with significant drainage issues.
If trench is to be a joint trench (shared with other utilities) the following separations must be maintained: 24 inches between gas and electric lines. 12 inches between water and electric lines. 24 inches between sewer and electric lines.
Dig a Trench
The trench should be about 18 inches deep and 9 to 12 inches wide. least 1 percent, so the force of gravity will work for you. This means that the drain should slope down a total of at least one inch for every 10 feet of pipe.
The general rule is 1/4″ of pitch per foot of run. However, some other issues do come into play. An extreme amount of pitch can cause the wastewater inside the drain to flow extremely fast.
A large diameter is useful for a drainage pipe because it can carry extra water. A 4-inch pipe can accommodate considerably more flow than a 3-inch pipe. Four- and 6-inch pipes are commonly used for French drains. Regarding speed, the 4-inch pipe is ideal for French drains.
Minimum trench width, W, shall not be less than 1.5 time the pipe diameter (D) plus 12 inches. In embankments or in cases of poor native soils offering negligible lateral resistance (e.g., Blow Count, N ≤ 5), then the trench width shall be 3 times the pipe diameter (D).
For instance, residential sewer line depth ranges from 18 to 30 inches. However, city sewer line depths are different. Your city's sewer lines must always be deeper than the deepest residential pipe to allow waste to flow downhill. As such, these lines can go as deep as needed.
The idea behind the 10:5 rule is that anytime you find yourself within 10 feet (3 meters) of someone, you should smile and make eye contact. When you are within 5 feet (1.5 meters) of someone, you should greet them with a friendly hello or other greeting.
Six Foot Rule: OSHA standards require that if an excavation is 6 feet (1.83 meters) or deeper, there must also be protections in place to prevent workers from falling into the excavation. This can include measures like guardrails, fences, or barricades around the perimeter of the excavation.
Trench safety measures
Trenches 20 feet deep or greater require that the protective system be designed by a registered professional engineer or be based on tabulated data prepared and/or approved by a registered professional engineer in accordance with 1926.652(b) and (c).
Dig-up test results in the U.S. and around the world indicate that PVC pipe can be expected to provide reliable service in excess of 100 years.
Once you start digging your drain depth will need to be anywhere from eight inches to two feet, depending on your needs and available options.
Cast Iron
Despite the heat resistance and noise-dampening properties of cast iron, it's not as suitable for underground water supply as newer materials. Cast iron is not resistant to corrosion, which can compromise the quality of the water supply and damage the integrity of the piping, leading to leaks and breaks.