No doubt, you’re accustomed to the idea of buried drainpipes. But did you know that you can bury downspouts from your gutter system?
But, understanding how to bury a downspout in your yard correctly is essential to preventing flooding, water damage, and topsoil erosion. Improper burying of a downspout can cause the drain to become an obstacle to mow around, a physical hazard, and lead to erosion.
But when done right, a buried downspout can help prevent drainage problems caused by ineffective gutters, downspouts, and extensions. Without proper drainage, overflows of the gutters are common and often lead to mold, wood rot, and erosion of the building’s foundation.
For clarity, we’ll discuss burying a downspout system, including downspout extensions, drain pipes, and fittings. Terms vary from region to region regarding what constitutes a downspout, so we’ll refer to the whole system as a downspout when discussing burying a downspout system, including cleanouts.
We’ll describe the benefits and drawbacks of burying your downspouts, the tools you’ll need, and offer a few tips and precautions to help make burying your downspouts more successful.
Benefits and Drawbacks of Burying Downspouts
A buried downspout is not only out of the way but also protected. This is also why plumbers bury pipes from your house to the sewer. The trick is to design the downspout trench to work right the first time, so you don’t need a second trench.
You may have other options other than burying a downspout in your yard. For example, you can attach the downspouts with straps to the side of a building, but they are visible and sometimes unsightly.
If your home has one, you can also hide downspouts behind a parapet wall. However, burying your downspouts is often the best option for some homeowners.
Here are a few of the benefits and drawbacks of burying your downspouts:
Benefits
- You can solve drainage and erosion problems instantly.
- Done correctly, you can even use the system for rainwater collection.
- You’ll avoid eroding your foundation’s support walls and help prevent mold and mildew.
- If you use mulch to bury a downspout in your yard instead of dirt, you can move it more easily in the future if needed.
- Using the building, plants, and mulch, you can hide most of the system if needed.
Drawbacks
- You may occasionally need to clean the system yourself or hire it to be cleaned by a professional gutter cleaner. In the case of buried downspouts, it can be a more challenging chore.
- You may need to rent power equipment if you do it yourself.
- You may encounter an obstacle underground, like a pipe or wire, adding unexpected cost and time to the project.
Steps and Tools for Burying Downspouts
Here’s a list of tools you may need to bury downspout extensions and other components in your yard:
- Personal protective equipment (PPE)
- Trenching tool or shovel
- Marking paint
- Long level, such as a water level or laser level
- Measuring tape
- Drill
- Corrosion-resistant screws
- Corrosion-resistant pop rivets and gun
- Handsaw
- PVC adhesive and primer
Step 1: First, you’ll need beginning and end points for your trench.
Map out a path using marking paint. The endpoint must be lower than the start point to ensure gravity can do its job effectively. You can do this with a water level, but most pros use a laser level.
Establish the slope you need for the drain to match the yard contour. One way is to shoot a leveled laser beam from the low end on the downspout to the proposed location. Using a measuring tape, measure from the laser beam to the ground at both the starting and ending points.
If there’s more distance between the laser beam and the ground at the endpoint than at the starting point, the proposed spot is downhill and should work. If not, or the ground barely slopes, a different location would be better.
Step 2: Next, look for obstacles.
Is there asphalt or a concrete sidewalk in the path? How about a large tree? Redesigning the gutter system may be more cost-effective than removing or avoiding the obstacles. You can keep going if no apparent obstacles will interfere, like a swingset or storage building.
Step 3: Dig a trench.
After establishing the destination and an obstacle-free path, it’s time to dig a trench. After marking the path on the ground, dig the trench deep enough for the bottom to be below the frost line if possible. If this is not feasible, bury the downspout deeply enough to avoid causing a hump in the yard.
You’ll want to use a motorized trenching tool or shovel to ensure a consistent downspout drainage slope. A buried downspout should maintain the gradual slope as closely as possible to avoid rises and falls. Retain the excavated dirt to use as fill-in after installing the drain pipe.
Step 4: Attach a PVC adapter to the end of the extension.
Professionals often do this before they bury a downspout extension. This converts the small, thin aluminum extension to a larger PVC or corrugated drain pipe. Corrugated pipe is more vulnerable to debris becoming caught in the ribs of the pipe, so PVC pipe is less likely to clog.
Step 5: Wrap the pipe.
Wrapping the pipe in landscaping fabric or sleeves can help prevent roots and debris from entering the pipe through the drain holes if the drain pipe has them. Place loose rock, like pea gravel, about 2” deep in the bottom of the trench. This will help water to flow under the buried downspout instead of getting stuck in the mud.
Step 6: Attach adapters to the drain pipe.
You can use Schedule 40 PVC for the drain pipe, but most pros use Schedule 20 PVC instead. Schedule 20 PVC has thinner walls than Schedule 40 PVC, so it’s less expensive to purchase. Plus, the fittings to turn corners are less costly than with schedule 40 fittings.
In most cases, you’ll want to start with the bell end of the pipe and attach a downspout adapter to the drain pipe using PVC glue. Blue PVC glue is best for wet materials; it repels moisture and dries in about 30 minutes.
Step 7: Attach the downspout extension to the adapter.
You may need an A-style downspout extension or a B-style to turn the water towards the downspout, depending on which direction you need the water to flow. Attach the downspout extension to the adapter using two pop rivets, and attach the pipe sections.
Additional considerations:
Perforated schedule 20 PVC pipe is usually 4” in diameter, so your trench must be wide enough to remove the loose dirt and still contain the pipe without bending it. Install the pipe end to end, cut off a section when you need to change directions, and install a fitting. If using perforated PVC pipe, make sure the holes face down.
Install a Y adapter if you need to divert the water in two directions. If you need a cleanout, install a T adapter and point it towards the grass. If you need to turn a corner, consider using two 45-degree fittings instead of one 90-degree fitting. This will reduce friction and keep the water moving, helping avoid a backup.
Tips and Precautions for Burying Downspouts
- Before burying downspouts, test any suspect areas for obstacles (like large rocks) by driving a 12” stake into the ground. This will help you avoid digging a trench only to discover an immovable object that will prevent you from reaching your destination.
- Most states have an 811 service to identify and mark buried wires and pipes if you suspect underground cables or pipes. Call before you dig; they’ll send a technician to mark any potential hazards. If 811 service is unavailable, a metal detector can often help find cast iron drain pipes and copper wires.
- If digging the trench by hand, get a helper. Digging can be exhausting work.
- Conserve some loose dirt from the dig for filling in the trench in the future. Even though the pipe is taking up space in the trench, the fill-in dirt will need to compact over time. Eventually, a rut will form as the soil compacts, so use the extra soil to refill the trench as necessary to prevent a fall hazard and additional erosion.
Buried Downspouts: Will You DIY or Call a Gutter Professional?
Understanding how to bury downspouts and downspout extensions the way professionals do can help you avoid common mistakes and do a great job of improving water drainage around your home and property.
Buried downspouts have pros and cons, but learning to bury downspouts correctly the first time is a great confidence builder and a great way to save money.
We’ve provided the tips and precautions you need regarding how to bury downspouts. However, you can also use the new knowledge to help select a trustworthy professional gutter company. We’ve helped homeowners just like you all across the U.S. with their guttering, roofing, and siding needs. Contact us for a free estimate.
