Poor drainage in a yard or close a structure can create awkward puddling, negatively impact the health of vegetation and lead to leaking or excessive humidity in a basement or crawlspace. 1 possible way to tackle a drainage issue is to install a French drain system which effectively transports water from structures or exposed low spots to a ditch, pond or municipal drain. The phrase “French drain” traditionally described a trench dug with a sloped bottom and filled solely with aggregates like gravel or rip-rap, but modern French drains typically include a lined, gravel-filled trench which also includes a perforated pipe to get more efficient drainage.
Dig a trench or trenches where you plan to install the French drain, making certain that the trench network extends through problematic low spots in the landscape, or alongside any exposed structure, to an appropriate outlet. Make the trench at least 12 inches wide and 24 inches deep, bearing in mind that the trench should slope gradually toward the outlet and your general thickness depends on the nature of the water issue. For example, if you are installing the French drain mainly to capture surface water, a shallow trench is appropriate, but if you are addressing potable water beside a structure, the trench should be as deep as the foundation footing.
Pound a stake into the ground at each end of each trench section and extend a string with a line degree attached between the bets, ensuring that the string is level and then mark the point at which the string is level on each stake.
Measure the distance between each pair of bets and calculate the essential drop in elevation between each pair of bets so that the trench bottom has a slope of at least 1 percent. For example, if a section of a trench is 50 feet, the thickness of the trench should increase .5 feet, or 6 inches, over that distance. Step down the second bet and adjust the string to this new degree.
Shape the bottom of the trench so that the string rests gently on the trench bottom.
Line the trench with landscaping material. This will definitely keep silt from entering the pipe and gravel, clogging it and shortening the effective life of this machine.
Place the 4-inch perforated PVC or corrugated plastic piping in the middle of the trench so that the perforations in the pipe have been oriented downward.
Cut any sections of this perforated PVC piping to dimension so that they fit in the prepared trenches, run a little piece of sandpaper across the inside and outside of the cut pipe ends to remove any burrs and dry fit the PVC pipe segments with couplings so that the entire piping system is joined together. When you have the pipes and couplings fit with them, make corresponding marks on each pipe end and the coupling it attaches to so it is possible to align them correctly before the PVC cement dries.
Spread PVC primer along the inside of each fitting and about the outside of the pipe end where the two will join together and let the primer dry for about 10 seconds.
Spread an even layer of PVC solvent cement over the primed surface on the pipe and in the matching and rapidly fit the pipe to the coupling a quarter-turn in the marked orientation. Twist the pipe or fitting as you push them together so that the marks are aligned and hold the pipe and fitting together securely for at least 15 seconds. Repeat this priming and re install, working from one end of this drain system to the other, until each of the pipes and couplings are securely joined.
Decide on a level on top of the pipe in various sections to be certain that the slight slope established on the trench bottom remains and remove or add soil or gravel under the pipe to correct the slope, as needed.
Add at least 12 inches of coarse, clean gravel across the drain pipe from the trench.
Cover the gravel layer with landscape material.
Fill in the remainder of the trench with gravel, other aggregate or the fill you eliminated when digging the trench.