Rigid PVC Pipe - This is the most commonly used PVC pipe for gutter drains. The nonperforated interior allows for rainwater and debris to pass through easily.
You can use whatever pipe material you want (corrugated steel, HDPE, reinforced concrete, vitrified clay, whatever). I suggest a plastic pipe. It's light, strong enough, easy to cut, and not too expensive. Steel will rust. Clay breaks. And concrete is heavy and expensive.
Use the 4'' smooth PVC as Brickeyee suggests. Water runs out of it faster than from the corrugated and debris does not accumulate. Use three gutter spikes placed at 120 deg as ``diameter lines'' in the open end of the pipe.
To ensure proper coverage and protection, bury your downspout extension at least 12 inches deep.
Rigid PVC Pipe - This is the most commonly used PVC pipe for gutter drains. The nonperforated interior allows for rainwater and debris to pass through easily.
However, there are some common issues caused by buried downspouts that homeowners should be aware of. One of the most common problems with buried downspouts is clogging. Over time, debris such as leaves, dirt, and twigs can accumulate in the pipe, leading to blockages.
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.
PVC pipes keep wastewater moving without any clogs, unlike corrugated pipes. Corrugated pipes can get damaged when buried deep under, but PVC pipes withstand the pressure and last longer. PVC pipes can last up to 100 years when properly installed and have a low failure rate compared to other materials.
PRO TIP: If round rock stone isn't available in your area and crushed stone is the only practical option then its recommended to use a sock wrapped drainpipe. The sock material will prevent the fines from the crushed rock from clogging up the inlet holes in your perforated or slotted pipe.
Direct burial installations for CANTEX Schedule 40 and schedule 80 PVC Pipe are simple, but must always be done in accordance with all national and regional guidelines.
We want our drain pipe to have a 1% slope so water will always drain properly. That means the trench and drainpipe must slope away from the house with at least 1-inch (2.5 cm) of fall for every 8-feet (2.4 m) of run.
A three-inch pipe is what's used in homes to pipe toilets. The four-inch pipe is used as the building drain under floors or in crawlspaces to transport all the wastewater from a home out to the septic tank or sewer. The four-inch pipe may also be used in a home if it's capturing two or more bathrooms.
PVC (Polyvinyl Chloride) Pipes: Lightweight, durable, and resistant to corrosion, PVC pipes are a popular choice for water drainage systems. They are available in various sizes, ranging from 1 1/2 inches to 24 inches, and wall thicknesses, making them suitable for a wide range of applications.
PVC is most commonly used for drain, waste, and vent lines. It is not recommended for use in potable water lines because it can leach chemicals into the water.
The minimum depth of any drain is 600mm.
Choosing the wrong downspout pipe, like a perforated pipe, defeats the purpose and allows water to leach through the line near the home's foundation. Instead, homeowners should use a solid corrugated pipe when burying downspouts. Solid pipe is the best option because it's flexible and can be run in one piece.
Cons of Using Corrugated Pipe:
Much lower flow rates. Since the pipe is flexible, water can sit in low spots after rain events. Have to be more precise to dig a flat and properly pitched trench before installing.
You can expect a service life of 100 years in typical drainage applications. Highly resistant to abrasion and chemicals, corrugated plastic pipe outperforms in environments that damage other materials.
If the pipe is placed upside down, with perforations towards the top of the pipe, it's not like it wouldn't work — the pipe performs better and transports water quicker if they are pointing down.
If you use a perforated pipe, the gravel layer at the bottom of the trench should fill up about one-third of the way. Purchase even larger gravel pieces if your arrangement does not contain a pipe. Get stones that are at least 1 1/2′′ in size, and cover the trench with gravel until it's two-thirds full.
Swales: A Natural Solution
They're a great option if you're looking for a more natural, eco-friendly alternative to French drains. A swale is typically lined with grass or vegetation that helps slow down and absorb water.
Installing a buried downspout drainage system is a great way to manage rainwater runoff and keep it away from your foundation. By minimizing the risk of flooding and soil erosion, buried downspouts offer a reliable, low-maintenance alternative to surface-level options.
Estimated Lifespan
Galvanized steel and aluminum gutters, the most common type of gutters, have an average lifespan of 20 years, while copper gutters, a more high-end option, can last up to 50 years.