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.
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.
Use PVC if you need a long-lasting, durable solution with better flow characteristics, especially for applications requiring higher performance. Use corrugated pipe for simpler, cost-effective drainage solutions in less demanding environments, such as yard drainage or agricultural applications.
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.
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.
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.
Gutters can be made from both aluminum and steel. Aluminum gutters are lightweight, rust-resistant, and available in many colors. Steel gutters, such as galvalume-and paint-grip steel, are heavier and more durable but can be more expensive and require more maintenance to prevent rust.
HDPE pipes are best used for underground drainage and sewerage applications because they are non-reactive to almost all common household chemicals. The uses of these pipes are only for potable and non-potable water. They are also non-toxic, corrosion-resistant, and can be used in longer lengths han PVC pipes.
This may be COLORBOND® steel, terracotta tiles, sealed concrete tiles, acrylic sheeting, glass, ZINCALUME® steel, or aluminium. This means that rainwater with any chlorides or acids dissolved in it from the atmosphere flows into the gutter.
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.
PVC is one of the most popular pipe choices for residential and commercial plumbing projects. Performance: PVC pipes are helpful for various drainage and plumbing applications. Their smooth inner surface minimizes friction, increasing the flow of fluids.
From the ground up, PVC pipes are often used for drain, waste and vent (DWV) systems. These carry wastewater from buildings and homes, eventually connecting to the city's main or an on-site septic system. The larger pipes in the DWV system branch off into smaller pipes as they reach different areas of the structure.
The trench should be at least 12 inches deep and wide enough to accommodate your pipe.
Because PVC is immune to corrosion, a minimum service life of at least 100 years can be expected. This figure is supported by a number of independent studies, as well as the experience of many long-term users of PVC piping systems.
While touted as an inexpensive, durable choice for communities seeking to replace their lead service lines, research shows that dozens of harmful chemicals, including many for which there are no drinking water standards, can leach into tap water from PVC and CPVC pipe walls, fittings, gaskets, and the cements used for ...
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.
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.
Walls of Cast Iron downpipes vary between about 9mm and 12.7mm thick plus the extra thickness of inner rust over time. Other metal downpipes will be about 2mm thick (give or take half a millimetre). If newly fitted you may be able to find out the precise thickness from the manufacturer or builder.
Type A SWR Pipes: Type A SWR pipes are primarily designed for rainwater and venting applications. They feature a smooth inner surface and are distinguished by their vibrant blue color. These pipes have a wall thickness of 1.6 mm, providing adequate strength and durability for their intended use.
PVC pipe schedules can range from 10 to 160 but schedules 40, 80, and 120 are the most commonly used for underground applications. The higher the schedule, the thicker the pipe wall.
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.
Vinyl Gutters
Heavy amounts of rain can cause the material to bend and bow. Even a ladder put up against them can create serious damage. In regions with hot sunny temperatures, vinyl gutters will crack under the harsh conditions and break apart.