DIY How To Install Gutters On A Metal Roof
DIY Projects

DIY How To Install Gutters On A Metal Roof

Installing gutters is one way to protect your house from water damage. The gutters catch the rainwater instead of letting it flow down directly to the walls or foundations of the home. It’s essential in ensuring a home’s structural integrity. Some homes with metal roofing don’t have existing gutters, especially those made decades back. Since the building code was different back then, gutters weren’t required. For first-time home buyers, it’s easy to look over this detail. It’s best to install gutters to save your house from possible foundation damage. Here’s a complete do-it-yourself (DIY) guide on how to install gutters on a metal roof. Keep on reading to learn more.

What You’ll Need

Installing gutters is a challenging project. You may hire a commercial gutter contractor if you’re not confident enough in your construction DIY skills. You’ll need these materials and tools for this project.

  • Prefab box gutters;
  • Gutter link (optional);
  • Rivets or gutter screws;
  • Downspout inserts;
  • Gutter caps;
  • Gutter hangers or brackets;
  • Sealant;
  • Angle grinder (optional);
  • Drill;
  • Metal snips;
  • Marker;
  • Level (optional);
  • Nail;
  • String or yarn; and
  • Chalk.

Before moving on, note that these materials, tools, and steps are for post-hung gutter installation. When installing a new roof or building your home, it’s best to talk to your metal roofing contractor about pre-hung gutters and other options.

Step-By-Step Guide On Gutter Installation

Make sure that you’ve already prepared the materials mentioned above. Then you can proceed with the installation by taking into account the following steps:

Measure The Roofline

Before purchasing your materials, get an accurate measurement of your roofline first. This will determine how many box gutters, caps, screws, and hangers or brackets you need. However, buying at least 10% more of what you need is best to avoid driving back and forth to the store.

Since box gutters come in 10-feet lengths, you can buy several pieces to connect and fit the gutter line. For small items like screws and rivets, it’s always best to prepare more than you need. Lastly, hangers or brackets are placed three feet apart at maximum. If your measurement specifies you need nine, get 12 to 15 pieces.

Cut And Prepare The Box Gutters

For this step, grab your marker, metal snips, sealant, and angle grinder if available. After finalizing the measurement of your gutter, it’s time to cut the pieces. Once you’ve marked the box gutter to the proper length, you may use metal snips or an angle grinder to cut it. 

You may use a gutter link or do the overlapping technique to combine two or three pieces of box gutters. Connect them using a sealant and secure them with rivets or screws. Whichever of the two methods you use, ensure to put sealant on the inside seams and all the parts with screws or rivets for efficient waterproofing.

Put The Caps In Place

Putting the caps in place is very simple. Apply a strong sealant on the edges before attaching it to the opposite ends of the box gutters. Then, secure them with screws or rivets. To ensure water-tightness, apply sealant on the inside seams and each screw mark.

Attach The Downspout Insert

The downspout insert is placed on the lowest side of the slope. Trace the bottom side of the insert on the box gutter to perfectly attach it. Next, use a hole saw drill bit to cut through the middle of the mark. With metal snips, cut off along the lines and remove the excess. See if the downspout insert fits and cut more if it doesn’t.

After cutting a hole, install the downspout insert by applying the sealant on its edges first. Then, properly secure it with gutter screws. Again, as a rule of thumb for waterproofing, reapply sealant on the inside seams. Doing so will prevent leaks and frequent gutter repairs.

Secure Gutter Hangers

Your gutter hangers will hold and support the gutter in place. Ensuring its durability is necessary for withstanding heavy rainfall. Before attaching them one by one, grab two nails and a string or yarn with chalk. Place the first nail on the highest slope point at 1.25 inches below the eaves flashing and the second one at the opposite side another half inch below. Attach the chalked string and carefully snap it to create an accurate mark.

There are various options for gutter hangers. The most DIY-friendly type is the fascia bracket. These brackets are easy to install. Attach them to the rafter tails using lag screws, following the chalk mark to maintain the slope.

Mount The Gutter

Once the brackets are secured, it’s time to install the gutter. It’s best to seek assistance to carry the gutter in place. Then, pre-drill holes on the bracket and box gutter to prep for machine screws. Again, applying the sealant on the inside part is recommended.

After attaching the gutter to the brackets, proceed in securing them onto the fascia board using hex head screws. The screws should be two feet or about 40 cm apart for better hold during heavy rains.

Install The Downspout And Rain Barrel

When the gutter is finally installed, you may now attach the downspout to the outlet using a strong sealant. If you’re not using a rain barrel or setting up a rainwater collection system, ensure the end of the pipe leads to the nearest drainage.


Installing gutters on a metal roof is one way to preserve the beauty and integrity of your home. Since water damage is a leading cause of frequent repairs, it’s best to prevent it. To ensure quality work, you may choose to DIY using this guide or hire experts.

Info on installing gutters on metal roofs in the UK can be found on Taunton Prestige Roofing blog.

Photo by Mitchel Lensink on Unsplash

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