While 4-inch corrugated is the industry standard, there are several reasons why a 3-inch downspout pipe could be the right choice for particular drainage application. 3-inch corrugated pipe moves roof runoff water at a higher velocity.
Corrugated is usually a go to for drainage. There are PVC attachments that connect to corrugated too, so in my honest opinion I would tie the downspout to the corrugated with a PVC wye with an extra hole to hook up a blower to force the buildup out of the popup. 4 inch corrugated is usually best too.
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.
Choosing the Best Material for Gutter Downspouts
Aluminum is lightweight and long-lasting. Copper is a stylish, durable option that develops a natural patina over time. Galvanized steel is strong and affordable, but prone to rust. Vinyl is low-maintenance and cost-effective, but not as durable as other materials.
Downspout Materials
The most used materials are aluminum, vinyl, steel, and copper. Aluminum downspouts are lightweight, durable, and inexpensive. Aluminum is the most popular material for gutters and downspouts. A vinyl downspout is easy to install and does not rust.
However, it's crucial to consider factors like expansion, proper sloping, UV resistance, and local regulations to ensure a successful and compliant installation. With these considerations in mind, you can confidently use PVC pipe for your downspout system and enjoy efficient rainwater management for years to come.
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.
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.
Polyvinyl chloride (PVC) is one of the most common types of piping, and it can be used for underground water supply in some applications. PVC is generally inexpensive and is a reliable, durable material. It is rigid, resists corrosion, and can have a lifespan of over 100 years.
Corrugated Pipe Provides More Flexibility Than PVC
That's why selecting the correct drainage materials for your yard is imperative. Solid corrugated pipe expands when ice backs up in the line and contracts during the thaw to move moisture away from the house.
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.
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.
To ensure proper coverage and protection, bury your downspout extension at least 12 inches deep. This depth helps protect the pipe from surface activities and ensures efficient water drainage.
Residential Downspout Sizes
Typically, residential downspouts come in two sizes: 2x3 inches and 3x4 inches. The former is often used for smaller roofs, while the latter is preferred for larger homes. A 2x3 inch downspout can handle roughly 600 square feet of roof area for every inch of rainfall within an hour.
Using either 3″, 4″ or 6″ drainage pipe is recommended on most residential and light commercial projects as these pipe sizes and applicable fittings are readily available and easy to install.
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.
Polyvinyl Chloride pipes are the most commonly used pipes for any drainage project. Due to the material's malleable properties, PVC pipes can come in almost any size. These types of pipes are great for drainage situations where the water and environment exert a great deal of pressure and weight.
Technically, a soil pipe (i.e. a black, white, or grey 110mm pipe) should only be installed above ground. Once the soil pipework goes below ground, it should be connected to a terracotta foul water drainage pipe.
Polybutylene, Galvanized Steel, and Lead Piping: The Worst Plumbing Pipe Materials.
If you are finding particles in the water, or have the taste mentioned above, you could have black alkathene. Black Alkathene pipework was often used as the supply pipe to properties in the 1960, 70s and 80s.
Copper pipes are considered by many to be the standard for residential hot or cold water applications. These lightweight and durable metal pipes are available in rigid 2- and 10-foot lengths with diameters of ½ inch to 1 inch.
Downspout PVC pipe is commonly used for water supply and is made from high-quality PVC material. HDPE PVC pipes have high flow capacity and are available in different sizes. The HDPE Downspout Pipes have a higher flow capacity than the HDPE pipes.
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.
PVC Gutters and Downpipes
It's lightweight and easy to work with, making it popular with fans of DIY projects. They are seamless and can be painted if you choose, giving you plenty of style options to suit your home. There is also no risk of rust or corrosion over time.