1 2

5-Inch K-Style Outside Box Miter (90°)

5-Inch K-Style Outside Box Miter (90°)

Color: White, 30 Degree
Unit of measure: pcs
icon of a box with stamp
Expected ship / pick-up date:
06 Oct | Typically ready in 1-2 days
We're ready to help. Call us at (610) 779-6934 and we'll happy to answer your questions.

Outside corners on a Gutter System must handle just as much water as the straight runs. Our 5-Inch K‑Style Outside Box Miters provide a ready‑made solution for 90° external corners, ensuring a neat appearance and a watertight joint. Formed from .019″ painted aluminum, these Box Miters are color‑matched to your Gutters and simplify installation by eliminating multiple cuts and joints.

5-Inch K-Style Outside Box Miter (90°) Key Features

  • Factory 90° corner

    Preformed Outside Box Miter creates a sharp, consistent corner every time

  • Fast installation

    Saves time vs hand mitering; square-cut Gutter ends slide into place and seal easily

  • Leak-resistant design

    Two broad factory laps accept sealant and rivets for a durable, watertight joint

  • Clean K-profile

    Wraps the outside corner for a neat appearance with minimal field fabrication

  • Color matched

    Offered in 20+ finishes to match your Gutters, Soffit, and Fascia trim

  • 5-Inch K-Style fit

    Sized specifically for 5-Inch K-Style Gutter Systems and common front-bead profiles

  • Compatible with hangers

    Works with Hidden Hangers; place Hangers within about 6" of each side of the corner

  • Durable aluminum finish

    Baked-on enamel resists weathering and corrosion for long service life

5-Inch K-Style Outside Box Miter (90°) Material & Specifications

Type: Outside Box Miter (K-Style), 90 degree
Gutter Compatibility: 5-Inch K-style only
Material: .019" Aluminum, baked-on enamel finish
Colors: 20+ standard colors (color-matched to Gutter System)
Joint Style: Factory-formed laps for sealant and rivets/screws (two seams)
Included: Miter only; fasteners and sealant sold separately
Use: Residential and light commercial outside corners at 90 degrees
Notes: Field trim ends if needed for fit; verify front-bead profile alignment with your Gutter stock

Installation & Maintenance Tips

This installation information is a general guide only and may not address your specific site conditions. Always follow local building codes, safety practices, and professional methods. If you are not experienced with this type of work, hire a qualified contractor.

Installation
  1. Plan and pitch: Confirm Gutter pitch (about 1/4 in per 10 ft toward the outlet). Snap a chalk line if setting new runs.
  2. Prep the runs: Measure and cut both Gutter runs square to the corner. Dry-fit the Miter to verify bead alignment and reveal.
  3. Sealant bed: Apply a continuous bead of high-quality Gutter Sealant inside the Miter laps where the Gutter ends will seat.
  4. Assemble at corner: Slide each Gutter end into the Miter so the laps overlap evenly. Maintain a small 1/8 in gap at butts for sealant and movement.
  5. Fasten: Use aluminum or stainless Pop Rivets (or #8 x 1/2" hex screws) spaced about 2–3" on center along both seams. Do not overdrive.
  6. Clean and tool: Wipe excess sealant; tool a smooth inside fillet to ensure a watertight joint. Keep the water path unobstructed.
  7. Support the corner: Install Hidden Hangers within about 6" of the Miter on each side to control load and maintain pitch.
  8. Final check: Sight the corner for square and level reveals. Hose-test to confirm no leakage at seams and proper flow to the Outlet.

Maintenance
  1. Inspect seams: Check the corner seams annually and after major storms. Reseal if you see cracks or gaps.
  2. Tighten hardware: Replace any loose or corroded rivets/screws with aluminum or stainless fasteners.
  3. Keep path clear: Clean debris at the corner so water does not back up at the seam.
  4. System check: Confirm nearby hangers are tight and gutter pitch is intact.

Compare Styles & Materials

Outside Box Miter vs Other Options

Outside Box Miter vs Strip Miter
  • Box Miter: Faster install, cleaner appearance, broad laps for sealant and rivets.
  • Strip Miter: Lower cost piece but more exposed seams and sealant; often slower on tricky corners.
Outside Box Miter vs Hand Miter
  • Box Miter: Consistent factory geometry, minimal field fabrication, predictable sealing.
  • Hand Miter: Maximum customization for unusual angles; requires more time and skill.

Best choice: Use the 5-Inch K-Style Outside Box Miter for standard 90 degree corners when you want speed, consistency, and a clean, color-matched finish. Choose a Hand Miter for non-standard angles or specialty details; consider Strip Miters for budget repairs.

Frequently Asked Questions

This is a general guide only and may not address your specific site conditions. If you are not experienced with this type of work, hire a qualified contractor.

Will this fit 6-Inch Gutters?

No. This model is for 5-Inch K-Style Gutters only. Ask for the 6-Inch version if needed.

What fasteners and spacing do you recommend?

Aluminum or stainless rivets (or #8 x 1/2 in Hex Screws) about 2–3 inches on center along both seams. Do not overdrive.

Do I need to miter-cut the Gutter ends?

No. Square-cut the Gutter ends. The K-Style Box Miter provides the corner wrap and sealing laps.

Which sealant should I use?

Use our high-quality Gutter Sealant, compatible with the painted aluminum. Apply a continuous bead and tool the inside fillet.

Is this for outside corners only?

Yes. This is an Outside Box Miter at 90 degrees. For inside corners, use an Inside Miter designed for K-Style Gutters.

Submit an RFQ or Questions

Please feel free to contact us - we promise to respond to your inquiry within the next business day. For longer requests, visit our RFQ page.