How to Install A Downspout For Your Gutter: A Step By Step Guide

Pooling water could cause significant damage to your home’s foundation, can cause soil erosion and can cause water to flood into your home’s basement. That makes downspouts an essential part of any gutter system.. For DIY homeowners or contractors it’s the last step when you install a gutter system. Once installed, water from your gutters travels down the downspout to ensure that water is directed away from your home and is not pooling.

At Western States Metal Roofing, we use our expertise with over 20 years experience in metal roofing to make your installation as simple as possible. You should refer to the manufacturer’s metal roofing installation guide as your main reference, but we help you out more by providing a written step by step guide. To help you visualize the process, we’ve also created a downspout installation video.

We will cover:

• What Is A Downspout?
• How Much Does Downspout Cost?
• Installing Downspout Elbows
• Attaching Downspout And The Downspout Strap
• Installing gutter splice
• Installing roofing underlayment at gutter, fastening, and gutter strap

What Is A Downspout?

A downspout is a roof drain pipe that’s intended to divert water from the gutter to the ground level. Downspouts are installed vertically and are connected with an outlet that penetrates the gutter and attaches to the downspout. The purpose of the downspout is to control where the water from your roof drains so that you don’t damage the foundation of your home.

How Much Does Downspout Cost?

The cost of downspout will depend upon the gauge, type of paint finish, and the size of the downspout. On average downspout will cost $3 to $5 per lineal foot. However, that does not include all of the additional downspout accessories. A good ballpark estimate is to double the cost of the downspout and that will be a close guess of the additional cost for parts such as: downspout elbows, downspout straps, and downspout outlets.

What Are Downspout Elbows?

Downspout elbows are used to direct water from the gutters and are placed at the top and bottoms of the downspout. They come in various angles, most commonly 45 degrees and 90 degrees. If you require a different angle, custom-made angles can be ordered upon request.

Prior to installing, you need to have the downspout outlet installed on your gutter. Prepare the lower section of your downspout elbow with the following steps:

How To Install Downspout Elbows?

1. Make a mark 1 ¼ inches at each corner of your elbow.
2. Using cutting snips, notch cut each corner.
3. Using a hand seamer, slightly bend the flaps inwards.
4. With a hammer, lightly smash down any burrs from cutting to help when butting the elbow and downspout together.
5. Place elbow to the downspout outlet. NOTE: Do not attach the elbow at this time.

How To Fix A Downspout Elbow That's Bent At The Wrong Angle

It's not uncommon to order your downspout elbow at wrong angle. Most elbows are 45 degrees, but it's not uncommon to have 30, 70, 90, or custom angles for your elbows. If you have the wrong angle on your elbows here's a simple solution to fix the problem.

How To Install Downspout

1. Measure distance from the fold of the flap to the wall.
2. Mark measurement and subtract 4 ¾ inches to leave room for the second elbow.
3. Drill a hole with a step drill bit on the outside section of the line.
4. Cut along the marked line with metal cutting snips.
5. Using a hand seamer, bend the inside hem to allow the 45-degree corner to lap the downspout.
6. When installing the downspout, make sure the seam either is installed toward the sky or against the wall.
7. Nest the elbow into the downspout section.
8. Attach two rivets to each side, making sure they penetrate both the straight downspout and the elbow.
9. Prepare the opposite end by notch cutting all four corners by 1 ¼ inches.
10. Repeat step # 5 through 8
11. The final section of downspout will come with a 45 degree downspout kick out already attached to the downspout.

How To Attach the Downspout And Install The Downspout Straps

1. Apply silicone sealant one inch from the edge of the downspout outlet’s outside perimeter.
2. Attach a section of the downspout from the dropout using two pop rivets on each side.
3. Attach the lower sections with two pop rivets on three sides of the downspout.
4. Downspout straps will be used to secure the downspout to the wall.
5. If you are connecting to metal siding then use metal-to-metal lap screws, attach the straps to the high seam of the wall panels. Otherwise use the appropriate screw for your wall condition. NOTE: Straps should be placed approximately every three feet.

Learn How To Install Gutters On A Metal Roof

If you’re learning how to install downspouts then we are guessing that you need to learn how to install gutters and downspout outlets. We have created a written installation guide and a supporting video to make this installation a breeze.

Looking for more homeowner guides and step-by-step installation help? You can find everything you need at the Western States Metal Roofing Learning Center to help you have an easy and successful installation.