How Do You Install Closure Strips on a Metal Roof?

How Do You Install Closure Strips on a Metal Roof?

A metal roof is an excellent investment. This material is more durable and lasts longer than traditional shingles. If it’s installed correctly, it’s practically impervious to moisture. But improper installation can create vulnerable areas that introduce moisture. Even small cracks can lead to major water damage in the home. 

Corrugated metal roofing is particularly vulnerable to moisture if it’s not installed properly. The wavy texture creates openings at the eaves. Learn how to install closure strips on a metal roof to create a tight seal and protect your investment.

What Are Closure Strips for a Metal Roof?

Foam closure strips fill any gaps where the metal roof meets the underlayment. This is especially important for corrugated metal panels, which have tunnel-like openings at the edge. Approximately 1 to 2 inches wide, these dense foam rubber strips come in different shapes to match your roof design.

There are a few types of closure strips:

  • Outside foam closure – Installed on top of the metal roof panel; these are common between the metal panels and the ridge cap, for example.
  • Inside foam closure – Installed beneath the metal roof panel; these are common along the eaves.
  • Vented closure – Seals the ridge and other areas that require ventilation; keeps water and bugs out while allowing for airflow.


Most metal roofs require a combination of outside and inside foam closures. These should be used at the end of any panels, including the eaves and locations where the metal roofing meets flashing materials.

Common locations for closure strip installation include:

  • Ridge cap
  • Eaves trim
  • Peak trim
  • High side eaves
  • Pitch break
  • Transition flashing
  • Endwalls
  • Chimney flashing
  • Pre-hung box gutters
  • Valley flashing


What Are the Benefits of Closure Strips on a Metal Roof?

While metal roofs typically cost more than some other common roofing options, they have a long lifespan and require minimal maintenance. Even if you’re trying to save money, you shouldn’t cut corners to reduce costs. 

Some homeowners might be tempted to cut costs by skipping the foam closure strip installation at the eaves. However, neglecting this step could be a big mistake.

Closure strips improve the function of your roof, protecting your home. They are water-resistant and durable, designed to withstand the elements and last a long time.

Because these strips create a tight seal, they block water and air from getting into the open areas beneath the roof. This has a number of benefits, including:

  • Preventing leaks and water damage
  • Increasing water-tightness
  • Discouraging mold growth 
  • Insulation for added temperature regulation inside the home
  • Reducing outdoor noises
  • Minimizing the amount of light entering the area beneath the roof
  • Preventing pests from entering the home
  • Minimal maintenance

Steps for Installing Closure Strips on a Metal Roof

If you’re wondering how to install closure strips on a metal roof, your best option will be to hire a roofing professional. Although you can do it yourself, you might waste time and money if you make a mistake that causes damage to your roof or property.

That being said, the process of installing foam closure strips is relatively simple. You may wonder, “How do you install closure strips on a metal roof?” Understanding the process can help you ensure that the job is done right.

These are the steps for applying closure strips to the eaves of a metal roof:

  1. Choose the right strips for your metal roof profile. Catalogs will often show the shape of the foam closure strip to help you select the one that matches your roof.
  2. Measure and mark 1 inch from the edge of your eave panel.
  3. Apply a strip of double-sided butyl tape to the marked line. Don’t remove the protective film from the top layer of the tape until you’re ready to adhere the foam closures.
  4. Use a chalk line to create a square reference mark on the roof underlayment.
  5. Lay down the first roofing panel, and make sure that the top and bottom are equidistant from the chalk line. Place the panel slightly above the butyl tape line.
  6. Once the roofing panel is in place, remove the protective film from the butyl tape. Only remove this strip from the area that you’re going to work on next. Keep the adhesive free of dust and debris.
  7. Lining up the shape of the closure with the shape of the metal roof profile, press the closure onto the exposed butyl tape. Make sure that the end of the closure includes a full corrugation. You may need to cut the excess off to achieve this.
  8. Don’t press the closure down too firmly in case you need to readjust it later.
  9. Apply silicone sealant to the top of the foam closure, and install the panel over it, using the proper fasteners.


To install closure strips at the ridge of the metal roof, follow the steps below:

  1. With the ridge trim in place, trace the edge of the trim.
  2. Measure one inch above the line that you drew, and mark it in several places.
  3. Attach a strip of butyl tape above the second line, making sure to follow the profile of the corrugation on the metal panels.
  4. Adhere the foam closure strip on top of the butyl tape. The peaks of the waves should be pointing down, fitting into the corrugated panels.
  5. Apply a bead of silicone sealant to the top of the foam closure.
  6. Install the ridge cap.


How to Maintain Foam Closures for Metal Roofing

Foam closures require little maintenance. They’re dense and resistant to the weather, and they are long-lasting. However, they won’t last as long as the metal roof. Their lifespan varies, but foam closures do need to be replaced periodically.

The best way to keep tabs on the condition of the foam closure strips is to monitor them visually. Examine them when you perform regular roof maintenance or inspections. Some things to look for include:

  • Gaps around the closure
  • Dangling or shifted foam
  • Dried out foam
  • Misshapen closures
  • Dissolved or missing foam


You should also inspect the foam closure strips after a major storm to make sure that they’re in place. If you experience problems inside your home such as water damage or a pest infestation in the attic, you may also want to examine the foam closures for flaws and deterioration.

The Importance of Ventilation

All types of roofs require adequate ventilation. However, this is more important for metal roofs because they are vulnerable to quick and extreme temperature changes. This quality leads to condensation, which can contribute to moisture issues in the home.

A properly ventilated attic pulls cool air in through the eaves and expels warm air through the ridge. This reduces the risk of condensation buildup between the metal panels and the underlayment, thereby lowering the chances of mold growth, high humidity, and rot.

Many foam closure strips are dense and made with a closed-cell material. If you’re using closures in areas that need to be vented, make sure that you purchase vented strips. These have an open cell design and permit air to flow through.

Do You Need Foam Closures for Your Metal Roof?

The best time to install foam closures is when you get a new roof. If you already have a metal roof but don’t have closure strips installed, contact a roofing professional. We can install foam closures to keep your new or existing metal roof in optimal condition throughout its lifespan.

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