Underground gutter drainage

The process to install underground gutter drainage to move water away from the foundation of a home, also known as a french drain.

Something that can be very damaging to the foundation of a home is exterior water. A gutter’s purpose is to move water from a roof to the desired location, but usually, this is right by the foundation of a home. A downspout of a gutter needs to divert water away from a foundation. How can this be done? By installing underground gutter drainage.

There are many ways to move water away from a home, but the most popular is a french drain. And again there are many ways to do this.

Years ago, in trying to move water away from our home, we buried a downspout extension moving the water away. We attached the extension directly to the gutter downspout. This technique solved the problem, but we realized we had no way of cleaning out the pipe. You can see how to bury a downspout just like we did before, it worked but would not recommend it.

So we decided to redo the buried downspouts and replace it with something more like a french drain. And this is how we did it.

What does it cost to install underground gutter drainage?

The cost of underground gutter drainage will be different for every home and every location. It will depend on the size of the catch basin you need plus the distance you want to move the water away.

If you are using a standard size catch basin (9″) plus moving the water 10ft away, the estimated price of you completing this project yourself would be about $105, this price includes a filter which cost about $25.

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Install underground gutter drainage

Before gathering your supplies you need to determine want size of catch basin you need, an excellent resource for this is NDS Home Drainage Center. After looking at this site, we decided we would need two 9×9 catch basins and one 6″ Speed-D catch basin for the areas we would be installing the underground gutter drain.

STEP 1: Dig trenches for drainage pipe

BEFORE digging CALL 811 to have utility lines marked.

The easiest way to dig the path of the drain is to lay out the materials (catch basin and pipe). Then using a shovel dig your trench.

SIDE NOTE: Use wood stakes and string to mark where you should dig in a straight line.

To make the french drain work, the pipe needs to be sloped away from the starting point. You should have a 1-1/2″ downward slope for every 10 feet of pipe.

SIDE NOTE: We always make ours have a bigger slope.

SIDE NOTE: If you are wondering how far away from a house should a gutter drain, the answer is at least 10 feet.

Also, the catch basin and emitter will need 4″ to 6″ of gravel under the base, so dig a deep enough hole at both of these places to hold the basin and 4″ to 6″ of gravel.

SIDE NOTE: In the next couple of steps, you will be checking the slope of the pipe and making sure all the materials fit together. So the trench does not need to be perfect on this step, you will probably do some adjusting later.

STEP 2: Assemble and place the catch basin

Now that the trench is dug, you can assemble the catch basin. Start by removing all the pieces from inside the basin.

Place the catch basin on a flat surface with one of the holes facing up. Apply silicone around the edge of the opening hole.

Then take the adapter and lock it into place, over the hole.

After apply more silicone around the edge of the adapter. Smooth the silicone with a finger to give you a sealed seam.

Complete this for the other side of the basin, the other opening.

Once the other side has been assembled, apply silicone to the end cap.

And push into place on one of the sides.

SIDE NOTE: I am assuming you are only using one opening. Sometimes you could use both if you are connecting basins to drain water.

To make sure you do not have water sitting in the bottom of the basin, drill one or two 1/8″ holes into the basin bottom. These holes should be as close to where the 4″ pipe will be attached. This way, the holes are not right next to the foundation.

Let the silicone dry completely before moving forward to give you the best seal.

SIDE NOTE: You can assemble the catch basin before digging to allow it to dry.

Once the silicone has dried, test the fit of the basin into the trench. Remove any dirt if needed.

Also, remember you need to have a 4″ to 6″ layer of gravel under the basin!

SIDE Note: You will want the basin to be level with the ground.

When the basin fits, remove from the hole and pour 4″ to 6″ of gravel into the hole.

Then place the catch basin onto the gravel.

STEP 3: Lay the drainpipe

Now that the catch basin is in place lay the drainpipe into the trench.

Check to make sure the pipe is draining away from the house, sloping 1-1/2″ every 10 feet or the bubble on a level is sloping down.

Once the pipe has the correct slope, connect the pipe to the catch basin. This is done by adding silicone to the area where the 4″ pipe is inserted.

Then readjust the catch basin and again make sure the pipe is sloped correctly.

STEP 4: Attach the drainage pop-up emitter.

With this tutorial, we are only moving the water 10 feet away from the house. So the pipe that was installed into the trench is the distance we will be running the water.

SIDE NOTE: If you can have the pipe drain without an emitter, this would be ideal. This way, the pipe can be cleaned easily. With the way our yard is, we had to use the pop-up emitter because we have no retaining wall or something simple to allow the pipe to end open.

TIP: If your pipe has a bell end you will want to remove that so that the 90-degree elbow can be installed. You can cut the pipe by using some type of hacksaw.

Now let’s install the emitter. Placing the 90-degree elbow onto the 4″ drainpipe. But first, pour 4″ to 6″ of gravel where the 90-degree fitting will be placed.

TIP: The 90-degree elbow has a hole on one side. This side that has the hole should fall toward the ground. This hole is to allow water to drain into the dirt slowly.

You will notice that you will probably need an extra pipe to be able to install the pop-up top so that it will be level with the ground. Cut a piece from the 4″ pipe, so that it will be long enough to extend the coupling fitting and pop-up.

Place this piece inside the 90-degree elbow. Then place the coupling fitting and the pop-up onto that. See if the pop-up is level with the ground or slightly above, adjust the extra 4″ pipe if needed.

Once everything looks good, remove the 90-degree, straight coupling fitting, extra pipe, and pop-up. Then using primer and glue, attach the pieces into place.

SIDE NOTE: You will notice in the pictures that we are attaching two drains together using a tee to allow us to use one pop-up emitter. I would not recommend this is you get a lot of water from the gutters.

STEP 5: Bury the downspout with dirt

Now that the drain is installed it needed to be buried with dirt.

TIP: Cover the catch basin cover and pop-up with tape to keep dirt from falling in.

Using the dirt that was previously removed, pack the soil around the drain until the ground is level again.

Remember to remove the tape from the basin cover, and pop-up then place the filter into the basin. This filter will help to keep the drain from getting clogged from debris from the gutter.

And that’s how to install underground gutter drainage or also known as a french drain. Please remember there are different ways to bury a downspout, so be sure to do your research on what will be best for your yard.