How to Install a Ridge Cap on a Metal Roof

By Amanda Lutz Updated May 16, 2024

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Metal roofing is one of the most popular types of roofs among homeowners due to its durability and long life span. To complete a successful do-it-yourself (DIY) installation of a corrugated metal roof, you must undertake the difficult task of correctly adding a ridge cap.

We’ll teach you how to navigate metal roof ridge cap installation to supply an extra layer of protection along your roof’s ridge line. We’ll also offer tips on how to source the right materials and reveal ways to find the right type of roof ridge cap.

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Metal Roof

Metal roofs cost, on average, between $7,081 and $110,150.

Brown concrete tile roof against a cloudy sky.
Tile Roof

The NRCIA reports that the average tile roof cost is $8,000 to $23,000.

Dark asphalt tiles on the roof on a sunny day.
Shingle Roof

Shingle-style roofs cost, on average, $5,000 to $18,000.


Roofing Safety Precautions

Working on a roof is one of the most dangerous types of home repair, especially if you’re a beginner. Take the following precautions to avoid injury:

Necessary Tools and Materials

Gather the tools and materials mentioned below before starting out on ridge cap installation:

Ridge Cap Installation Process

Once you have all the needed materials for ridge cap installation on a metal roof, read your safety harness instruction manual or watch a full video tutorial. Secure your ladder in place, and ask a friend to help deliver your tools to the roof with a pulley system. Once you’re safely on the roof with all tools nearby, you can start working. Read the guide below for a precise guide on how to install a metal roof ridge cap:

Preparing the Roof

Prepare your metal roof before installing the ridge cap. This will prevent errors that could compromise the entire project.

  1. Get end pieces ready: Measure 1 inch from the edge of the ridge cap, and make a guide mark. Pry open the hems to the 1-inch mark, and cut away 1 inch of the hem on both sides. Mark the center of the ridge cap so that it aligns with your roof’s slope using a speed square and a protractor. Fold the uncut side to a 90-degree angle with a hand seamer, then fold the cut side down 90 degrees. Prepare one end piece for each side.
  2. Clean the ridge cap installation area: Putting in a ridge cap typically comes after installing metal roofing panels. Remove materials you’ve left behind after the metal roof installation including sawdust, leftover building materials, dirt, or leaves. Metal panels should be clean working surfaces when you’re on them.
  3. Consider which way ridge overlaps will face: You can create a smooth ridge line by placing overlaps in out-of-sight spots. Place them away from your driveway, for example.
  4. Mark the ridge line: Your ridge cap will cover the edges of the roof panel to create a smooth line. Begin by creating a guide with your chalk line. Center a piece of ridge cap on the building’s peak and mark the cap’s lower edges on both sides of the ridge. Repeat this step every 15 feet.

Installing the Ridge Cap

Begin ridge cap installation once you’ve prepared the ridge line. Follow the guide below to continue.

  1. Adhere closure strips in place: Measure 1 inch above the chalk line, and run a strip of sealant tape along the full length of the ridge. Repeat this step on the opposite side of the roof. Remove the backing that runs along the top of the sealant tape. Run closure strips along the length of the ridge and interlock them as you go. Skip this step if you’re installing a vented ridge cap.
  2. Install a ridge cap vent: Your ridge should have a 2-inch opening. Unroll the ridge vent, and fit it into the space between roofing panels. Follow this step only if you’re using a vented ridge cap.
  3. Install the first piece of ridge cap: Use the ridge and chalk lines as guides to center the ridge cap. Once you’ve positioned the cap correctly, set it on the closures, and press it down firmly. Secure the ridge cap in place with 2-inch metal screws through every other panel rib.
  4. Overlap and install the second piece: Apply sealant to the inside of the ridge cap 2 inches from the overlapping edge. Lap the piece of ridge cap 6 inches over the end of the first piece and center it using the first piece and chalk lines. Press the second piece into place and use screws to install it using the same methods as with the first.
  5. Continue installing ridge cap pieces: Repeat the fourth step to install ridge cap sections along the entire roof ridge.
  6. Install the end of the ridge cap: You’ll need to trim the final piece for a proper fit. Measure from the prepared edge, and mark the piece so that it’s 6 inches longer than the final gap. Cut the edge, and then secure the final piece of the ridge cap in place.

Types of Ridge Caps

There are two types of ridge caps for metal roofs: closed ridge caps and vented ridge caps. Both should fit over the ridge of metal roofs at any slope, and each can be painted to match your existing roof material.

Ridge caps are typically either 7 inches by 7 inches or 10 inches by 10 inches, and they’re available with or without hems.

Closed Ridge Caps

Closed ridge caps create a tight barrier that helps to prevent water from entering your roofing system. They’re fully sealed on all four sides and have solid closures that are made of dense foam that fits over the ribs in your roof’s standing seam panels.

The neat appearance of closed ridge caps makes them popular among homeowners, and they’re the best choice for anyone who lives in an area with frequent, heavy rainfall.

Vented Ridge Caps

Vented ridge caps and soffits under the eaves increase air circulation while keeping water out of your home. Vented ridge caps require additional material to stop the entry of debris or insects.

Vented ridge caps are ideal for metal roofs in areas of high humidity where moisture buildup is common. They’re not as successful in areas that experience frequent winds and heavy rainstorms as water could still get under the shingles to your house’s roof decking.

Common Problems When Installing Ridge Caps

Proper installation of your ridge cap is critical to prevent water from entering your roofing system. If you notice any of the issues below during installation, tackle them immediately.  

Our Recommendation

A ridge cap can help to keep water out of a metal roofing system, but only when it’s installed correctly. Make sure to understand how ridge caps work, how to properly install them, and how to troubleshoot potential issues before beginning. If you’re unsure of your ability to safely and properly install metal roof ridge caps, consider hiring a professional roofer.

Installing Ridge Caps on Metal Roofs FAQ

How do you secure a ridge cap on a metal roof?

To properly secure a ridge cap on a standing seam metal roof, apply each piece to the corresponding adhesive closing strips, and secure each in place with metal screws. Overlap ridge cap pieces at 6-inch intervals to prevent leaks.

How do you finish the end of a metal ridge cap?

To finish a metal ridge cap end, create a 1-inch folded edge to match your roof’s slope. Finish by folding down the edges.

How do you overlap a metal roof ridge cap?

To overlap a metal roof ridge cap, place each one 6 inches over preceding pieces. Apply a bead of adhesive 2 inches away from the edge before installing, and be sure to apply overlapping pieces to closure strips. Complete the process by securing pieces with metal screws.

What goes under the ridge cap?

Certain protective materials such as closure strips and vent material go under your ridge cap to prevent trapped debris and keep moisture out.

What is the purpose of a ridge cap on a metal roof?

The purpose of a ridge cap on a metal roof is to keep moisture and debris away. The ridge cap creates an overlapping seal to allow water to flow over it without getting beneath roofing material.