Installing flashing correctly is one of the most important steps when installing a new metal roof. A metal roof will only be watertight if the flashing is done correctly, so it’s crucial to take your time and do it right.

Over the years, I’ve made mistakes with flashing on past roofing projects that have ended up costing me more to fix later on. That’s why I’m excited to share with you the lessons I’ve learned from experience about installing flashing on a metal roof the right way. In this blog post, I’ll cover tips on how to install flashing on metal roof, and some tricks of the trade I’ve picked up from other roofing professionals over the years.

By following along with the steps outlined here, you can be confident that your new metal roof will stay protected from leaks for many years to come.

What Will You Need?

Before installing flashing on your metal roof, gather all the necessary materials and tools. Some of the items you’ll need include:

• Metal Roof Flashing (either aluminum or steel)
• Roofing cement or sealant
• Drill with metal drill bits
• Tape measure
• Tin snips
• Hammer
• Nails or screws 
• Ladder and safety equipment

Double check that you have everything on this list before you begin. It’s much easier to have all of your materials ready beforehand than having to run back and forth while you’re working on the roof.

10 Easy Steps on How to Install Flashing on Metal Roof

Step 1: Measure and Cut the Flashing

First, take accurate measurements of the area where the flashing needs to be installed. Use your tape measure to measure the length and width of the areas to be covered by flashing. Add 2-3 inches to each measurement to allow for adequate coverage and overlap. Once you have your measurements, mark the dimensions on your metal roof flashing. Use the tin snips to cut the flashing accurately. Always remember to measure twice and cut once.

Step 2: Apply the Sealant

After cutting the flashing to the required size, the next step is to apply the roofing sealant. The sealant ensures a water-tight seal, preventing any leaks. Apply a thick bead of glue on the underside of the flashing, spreading it evenly along the edges.

It’s essential to use enough sealant to cover the area thoroughly, but be careful to use only a little, as this can lead to a messy installation. Remember to wear gloves for safety and easier clean-up.

Step 3: Secure the Flashing

Now, it’s time to secure the flashing to your metal roof. Position the flashing on the desired location, ensuring it overlays the adjacent roofing material for proper water runoff. Once you’re confident with the positioning, use your drill with a metal bit to drill holes into the flashing and the roof.

Be careful not to drill too many holes, which can lead to potential leakage spots. After drilling, secure the flashing to the top by driving the nails or screws into the pre-drilled holes.

Step 4: Apply Additional Sealant

After fastening the flashing, the next step is to apply an additional sealant over the top of the screws or nails. This acts as an extra layer of protection to prevent any potential leaks from seeping through the screw or nail holes. Use your sealant to cover the heads of the screws or nails completely.

Ensure not to miss any, as even a single leak can cause significant damage over time. Smooth the sealant with a putty knife or your finger (if you’re wearing gloves), ensuring a neat and professional finish. Allow the glue to cure per the manufacturer’s instructions before proceeding with the next step.

Step 5: Check Your Work

After the sealant has fully cured, it’s crucial to check your work. Examine the flashing installation to ensure there are no gaps or loose sections. Flashing should be flat against the metal roof, and the screws or nails should be fully covered by the sealant. If you notice any issues, address them immediately, either by adding more glue or by re-fastening the flashing.

Remember, you aim to create a fully waterproof barrier to prevent leaks into your home. Take your time with this process; it’s always better to spend a little extra time ensuring a job well done than to deal with the potential consequences of a poorly installed flashing on your metal roof.

Step 6: Check the Flashing Around Roof Openings

Roof openings, such as chimneys and skylights, require special attention when installing flashing. These areas are more prone to leaks if not sealed correctly with flashing. Make sure you take your time to carefully install flashing around these areas, ensuring they are fully waterproof and properly attached to the metal roof. You may need additional roofing sealant and flashing pieces to cover gaps or tricky areas.

Step 7: Install Counter-Flashings

Counter-flashings prevent water from backing up under the bottom edge of the flashing, especially in areas where two different pitches of the roof meet. Install counter-flashings by positioning them under the bottom edge of the flashing and securing them with roofing cement or sealant and nails or screws. Again, ensure there are no gaps and that everything is fully waterproofed.

Step 8: Seal Any Gaps

During the flashing installation process, you may have missed a few spots where water could seep through. It’s time to double-check and ensure every gap or seam is sealed correctly. Once again, apply your trusty roofing sealant to any potential problem areas.

Pay special attention to joints, intersections, and places where different roof elements meet. Ensure enough glue is applied to these areas to create a fully waterproof barrier. Just like with previous steps, allow the adhesive to cure as per the manufacturer’s instructions.

Step 9: Inspect and Clean Up

After you’ve ensured all gaps are sealed, take a final look at your roof to ensure everything is as it should be. The flashing should lie flat against the metal roof with no loose spots. The sealant should have covered all gaps, joints, and intersections, creating a fully waterproof surface

If you’ve been diligent, your roof should now be well-protected against potential leaks. As a final step, clean up any debris or leftover materials from your work area. Dispose of any waste material properly and return your tools to their storage places.

Step 10: Periodic Maintenance

Proper maintenance is the last but not the most minor step to ensure the longevity of your flashing and your roof. Regularly inspect your roof for any signs of damage or wear. Check the flashing for any lifting, curling, or bending that could allow water to seep underneath. Also, look for areas where the sealant may have deteriorated or peeled away.

If you find any such issues, address them immediately by re-sealing or replacing the flashing as required. Annual inspections are recommended, but more frequent checks may be necessary in areas prone to heavy rainfall or wind. Remember that preventative maintenance can help avoid costly repairs down the line.

By following these steps and taking necessary precautions, you can successfully install flashing on your metal roof and protect it from potential leaks.

5 Additional Tips and Tricks

1. Preparation is Key: Before starting the process, ensure you have all necessary tools and safety gear. This includes but is not limited to, a good quality ladder, safety harness, gloves, and eye protection.
2. Measure Twice, Cut Once: Make precise measurements when cutting your metal flashing. Remember the adage, “measure twice, cut once,” to avoid wasted material and time.
3. Seal Properly: To prevent leaks, ensure the flashing is sealed properly. Use a high-quality sealant that is specifically designed for metal roofs. Apply the sealant generously along the edges of the flashing.
4. Overlap is Essential: When installing multiple flashing pieces, overlap them by at least two inches. This overlap is crucial for preventing water seepage.
5. Check Weather Forecast: Always check the weather forecast before installing. Aim for a clear, dry day, as rainy or windy conditions can make the installation process hazardous and compromise sealants’ effectiveness.

With these additional tips and tricks, you can ensure a successful installation of flashing on your metal roof.

5 Things You Should Avoid

1. Ignoring Safety Measures: Pay attention to the importance of safety gear. Failing to use a safety harness, gloves, eye protection, or a sturdy ladder can lead to severe injuries.
2. Using Incompatible Materials: Avoid using sealants or other materials not designed for metal roofs. These can cause damage over time or fail to provide the necessary protection against weather conditions.
3. Poor Sealing: Do not skimp on sealant application. Insufficient sealant can result in leaks and damage to your property.
4. Incorrect Flashing Overlap: Avoid insufficient overlapping of flashing pieces. Incorrect overlap can lead to water ingress, causing severe issues.
5. Ignoring Weather Conditions: Consider the weather forecast while planning your installation. Unfavorable conditions such as wind or rain can not only make the installation process dangerous but also impact the sealants’ effectiveness and the installation’s overall integrity.

By avoiding these mistakes, you can ensure a smooth and long-lasting flashing installation on your metal roof.

Conclusion

In conclusion, how to install flashing on metal roof may seem like a daunting task, but with the right knowledge and tools, it can be a manageable and rewarding DIY project. Following the step-by-step guide, you can ensure that your metal roof is adequately protected from any potential water damage.

Additionally, feel free to seek professional help if you are unsure about any steps or encounter unexpected challenges during the installation process. With the proper flashing in place, your metal roof will not only enhance the aesthetics of your home but also provide efficient protection against the elements for years to come.

This blog post has been helpful and informative in guiding you through installing flashing on your metal roof. As always, stay informed and proactive in maintaining your home’s structural integrity to ensure safety and comfort for you and your family. Happy DIY-ing!