Avoid: public sidewalks, septic systems, drain fields, or underground storage tanks. SaFeTy ConSideraTionS Decide how you are going to manage your stormwater and have all the materials ready for installation before you disconnect. Use only durable, gutter grade materials. Clean gutters twice per year and monitor downspouts and extensions for.
The downspouts on your house’s guttering system carry many gallons of rainwater off your roof and onto your yard. To direct the water farther away from your house’s foundation you can to install underground downspouts. These downspouts filter leaves and debris from the roof before they enter the ground and end several feet away from the foundation. The water simply drains into the ground at the end of the underground downspouts. You can also hire a professional to tap into an underground drainage system if you have one installed on your property.
1
Dig a trench eight to 10 feet long, 12 to 14 inches deep and about six inches wide for each of the downspouts on your house. Try to drop the depth of the trench at least 1/8-inch per foot to help keep the water moving away from the house.
2
Fasten a piece of PVC 45-degree angle joint to one end of a piece of eight-to-10 -foot long, 4-inch diameter plastic SDR-35 sewer pipe. Wipe PVC glue, using its applicator, around the outside and inside of the fittings for these two pieces and twist them slightly as you slide them together to seat the glue.
3
Slide the angle fitting and a downspout filter together. Hold the pipe and filter end against the downspout so the filter is slightly above ground. Mark on the downspout where you need to cut it. Cut the downspout with a pair of tin snips or a hacksaw.
4
Attach the downspout filter to the downspout. Secure the filter to the house with two screws. Slide the 45-degree angle joint onto the bottom of the filter, using PVC glue to secure it. The sewer pipe should be lying in the trench at this point. Push some dirt underneath the pipe and angle joint in the trench to provide support, if necessary.
5
Dig a hole two to three feet deep under the end of the sewer pipe, using handheld posthole diggers. Pour a bag of pea gravel into the hole. This provides drainage for the water that runs off the roof.
6
Slide a PVC T-connector onto the open end of the sewer pipe. Align the T-connector so it is going up and down on the pipe. Set a PVC filter on the top opening of the T-connector. These connectors are going underground and do not need gluing.
7
Adjust the T-connector so that the top side with the drain is flush with the ground. Rainfall runoff from the downspout will first fill the hole you filled with pea gravel. Any excess will flow up and out of the pipe and on the top of the ground. You can open the drain to clean it out whenever necessary.
8
Fill the trench, packing dirt around the pipe. Smooth the surface.
Things You Will Need
- Shovel
- PVC 45-degree angle
- 4-inch diameter plastic SDR-35 sewer pipe
- PVC glue
- Downspout filter
- Screws
- Screwdriver
- Tin snips or hacksaw
- PVC T-connector
- PVC filter
- Handheld posthole diggers
Tip
- Take a picture of where you dig each of the underground downspouts. If you ever need to dig them up to make repairs, you’ll be able to locate their position.
References (2)
About the Author
Denise Brown is an education professional who wanted to try something different. Two years and more than 500 articles later, she's enjoying her freelance writing experience for online resources such as Work.com and other online information sites. Brown holds a master's degree in history education from Truman State University.
Cite this Article Choose Citation Style
Brown, Denise. 'How to Put Downspouts Underground.' Home Guides | SF Gate, http://homeguides.sfgate.com/put-downspouts-underground-28319.html. Accessed 23 June 2019.
Brown, Denise. (n.d.). How to Put Downspouts Underground. Home Guides | SF Gate. Retrieved from http://homeguides.sfgate.com/put-downspouts-underground-28319.html
Brown, Denise. 'How to Put Downspouts Underground' accessed June 23, 2019. http://homeguides.sfgate.com/put-downspouts-underground-28319.html
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Introduction to Wet Basement Problems
Wet or damp basements are a common problem in homes new or old, although the problem is more prevalent in older homes for a variety of reasons.Wet basements create mold and mildew, and ruin flooring and wall materials. They can prevent a valuable space like a basement from being used effectively as living space. Even worse, a wet basement wall can become a structural liability if not resolved, and will often prevent a home from being sold.Basement waterproofing is inexpensive and easy to install as the home is being built. For an existing home adding basement waterproofing is very expensive because it requires extensive excavation and landscape repairs.The good news is that not all wet or leaky basements require adding waterproofing or new foundation drainage systems as a solution. Very often the source of wet basement walls or a leaky basement is on the outside of the home, above the ground and easily repaired. You may find that improper roof drainage, improper ground slope, or even your neighbor's drainage may be causing your problem.Basement Waterproofing Isn't Always the Solution
Water flows downhill, and that means down your driveway, patio or lawn, and into your home and down the basement wall until it stops. Your basement wall is now functioning as a mini Hoover dam, causing a reservoir of wet earth and pressure to build up against your basement wall. The pressure pushes the water into your wall and through the smallest crack. Worse yet, the pressure creates its own cracks in the wall.The more water produced by a rainstorm and the more sources of water being thrown into your basement wall, the worse your problem. This problem can become so severe that structural failures occur from the pressure against the wall or from the erosion of the subgrade upon which the foundation of your home rests. At that point, whole corners of your basement wall may crack and fall away, requiring expensive foundation underpinning.Waterproofing only reduces water penetration but does not address the root cause of the water problem. Furthermore, expensive interior or exterior foundation drainage systems do not address the root cause of the problem, either.Check for Grade Sloping Into The House
As mentioned earlier, wet basements were more common in older homes. One of the reasons is that the soil that was back-filled against the basement foundation when the home was built tends to settle more than the surrounding undisturbed soils. As the back-filled soil settles, it may create low spots, allowing water to drain into the house.Walk around the entire house with a critical eye, making sure the grade (dirt or lawn) slopes away from your foundation and basement walls. At about out 24' away from the house, the ground should fall or slope away by at least 8'. Regrading the soil around a foundation remedies the problem in many situations.If the ground is near level at the house foundation and basement wall—or worse, sloping into the house—then you have a problem that requires regrading or re-landscaping so the soil is higher against the house and not draining into the foundation.Check for a Patio Sloping Into House
Patios may also contribute to the wet basement problem, as they may sometimes improperly slope toward the house. You may have a situation where the outside patio door threshold height is fixed and the lawn is higher than the door threshold. The patio (concrete or pavers) just follows the slope of the higher lawn, down toward lower height of the door threshold.A small patio can be sloped gradually away from the house toward the lawn. With large patios, they are sometimes constructed so they slope toward the center of the patio, where a drain funnels water through an underground perforated plastic drain pipe leads to the lawn area, possibly with a pop-up relief outlet.Check for Driveway Sloping Into House
Another culprit may be a driveway that is improperly sloping into your house, or maybe you have a sunken piece of driveway near a downspout. The large, flat surface of a driveway can carry a lot of water, so checking its drainage is important.This problem is especially prevalent in home lots having a small width, where the driveway may touch both your foundation wall and that of your neighbors.If your driveway is draining into your house, then a solution may be to have a concrete contractor pour a small curb up against your house where the driveway abuts it. This way, the water is directed against the curb and flows down the driveway into the street, rather than against your foundation or basement wall.Check Roof Downspout Discharge
The problem of improper drainage outside the home can be made much worse by an improper discharge of the roof downspouts. Roof downspouts can add a literal flood of water to areas prone to drainage problems.To give you an example of how much water can be flooding out of your downspouts, a 1500 square foot roof will shed about 940 gallons of water in a 1-inch rainstorm. Assume that water flows out of an average of four downspouts, you may have as much as 235 gallons of water pouring out of one downspout!In many cases, you will find downspouts dumping water right near the foundations of a house or connected directly to an outside drain pipe leading the water down into the basement wall or footing drain system. This condition needs to be corrected. Downspouts coming from your roof gutter must have extensions leading several feet away from the house. Also, check to make sure the gutters are clean and flowing properly.Check for Your Neighbor's Runoff Draining Into Your Site or House
Another common source of problems, especially with small lots where the houses are close together, is that of water being discharged onto your property from a neighbor's house.Make sure your neighbor does not have a downspout extension dumping water onto your property, finding its way across your driveway and draining into your house.A solution for the problem of water runoff from your neighbor draining onto your property can sometimes be handled with what is called a French drain system. This is a landscape project in which a gravel-filled trench helps direct water in the direction you want.