Whether you’re a professional builder about to undertake his first project or a homeowner who’s interested in learning more about home maintenance, you’ll want to know about corrugated drain pipes and how to install them. Fortunately, you don’t have to look far since this guide is made just for you! Read on to get more info about this type of drain pipe.
What’s a Corrugated Drain Pipe?
A corrugated drain pipe is usually made of flexible plastic, but you can also find corrugated steel pipes in the market. As its name suggests, the pipe has ridges or corrugations along the length of its body. It’s available in two types: solid and perforated.
Corrugated drain pipes are available in a wide range of inside diameters (from as small as four inches to as large as 18 inches), so you can easily choose an option that best suits your needs. Many hardware stores offer different lengths of corrugated drain pipes, so they can cater to you whether you’re looking for just 10 feet of pipes or need 100 feet of it.
What Is It Used For?
Solid corrugated drain pipes are used in connecting sections of wastewater systems. Perforated drain pipes, on the other hand, have small holes on one side of their body that, depending on how they’re used, allow water to leak in or leak out of the pipe.
Perforated pipes are commonly used to keep groundwater and surface water away from the foundation of the home, preventing basement flooding and protecting the house from water damage. They’re also used by homeowners who want to drain rainwater from their loans and by farmers who need to drain waterlogged fields and save their crops. Perforated corrugated drain pipes are also highly useful in septic tank drain fields. Septic tank builders design a system in which clarified sewage flows through the pipe, which then leaks the fluid from its perforations and spreads it around the drain field.
How Do I Install It?
The answer to this question depends on how you want to use corrugated drain pipes. If you’d like to use perforated pipes in a French drain (a trench that redirects ground or surface water away from a home), you must choose between installing the pipe under the basement floor or burying it under the ground around the external side of the foundation. The former prevents water from entering the basement, while the latter catches water as it enters the basement and drains it to a sump pump.
Each option has its own pros and cons, so do your research and find out which one best fits your needs. An external French drain can function for around a decade without any maintenance, but it’s also highly prone to clogging since it’s surrounded by sand, silt, and soil that can enter the holes. If it clogs, you’ll need to do an excavation on the site, which can damage any structure (like a deck, a patio, or a pathway) that may be on top of it. An interior French drain isn’t prone to clogging because it’s not exposed to dirt and debris, but it requires a sump pump. Sump pumps themselves aren’t a problem but, if they’re made of weak materials like plastic, they can easily break down and facilitate basement flooding. If the contractor forgets to install a battery backup, the sump pump will stop working during a blackout and expose the basement to flooding. Once you’ve made your choice, you can take any of these steps.
For External French Drains
1. Decide where you want to place the drain pipe. As much as possible, choose an area that has a downward slope so it’s easier for the water to flow away from the house’s foundations.
2. Once you’ve chosen the area, start digging the trench. Ideally, it should be six inches wide and around 24 inches deep.
3. Get a piece of wood (a 4×4 post will do) and use it to pound the ground in the trench you’ve dug. Doing this makes the soil compact and reduces the chance of having dirt enter your corrugated pipes.
4. Shovel gravel into the trench, ensuring that it forms a two-inch layer.
5. Measure the length of the trench and cut your corrugated drain pipe to that length.
6. Lay the pipe on the trench, ensuring that its holes are facing downward.
7. Decide if you want to drain the groundwater/surface water using gravity alone or with the help of a sump pump. If you opt for the latter, buy a sump pump and connect your drain pipe to it.
8. Shovel in more gravel until there’s only around an inch between the surface of the ground and the gravel layer.
9. Decide if you’d cover the trench with soil or not. Leaving it as is it is a better option since it reduces the chances of clogging; you won’t even have to worry about aesthetics since the gravel in the trench will give your garden a rustic-inspired look. But, if you want to hide the trench, you can always do so by covering it with sod. Before doing so, though, make sure to lay a filter fabric on top of the gravel. This will provide additional protection from sand, silt, and dirt that may enter the pipe’s perforations and cause it to clog.
For Interior French Drains
1. Using a jackhammer, cut through your basement’s concrete floor around its perimeter. Make sure you reach the footing.
2. Remove the concrete.
3. Shovel gravel in the trench until it forms an inch-thick layer.
4. Lay the corrugated drain pipe on top of the gravel.
5. Connect the pipe to a collection pit that will hold the water. The pit, in turn, should be connected to a sump pump that will remove the water away from the basement.
6. Pour concrete over the trench, but make sure to leave a two-inch gap around the edges to ensure that the water from the basement walls will trickle to the trench and into the drain pipe.
Final Note
Home DIYers can use corrugated drain pipes in French drains on their own. But, before doing so, they must get the advice of a building inspector, who can guide them and ensure their project won’t violate the local building codes. They must also hire a professional electrician who will set up the sump pump. Of course, if they don’t have the time to do this project, or if they’re not confident with their skills, it’s definitely better to get the help of experienced contractors.
