Installing a metal roof over shingles is a smart decision for homeowners who want longevity, energy savings, and long-term protection. It might appear difficult initially, but it is much simpler to follow once it is divided into steps. You can start by laying underlayment to form a moisture barrier and add furring strips for airflow (optional).
Then, measure things correctly, cutting the panels accurately, and getting them firmly attached. You will also need to add flashing and edge trim, and the last step will be adding ridge caps at the very top of your roof to ensure it is completely weatherproof.
These steps will make the process much easier to work out, but understanding them will also allow you to recognize the significance of the correct installation as a long-term protective measure. If you are unsure about the process, you can get roof installation services from a professional contractor.
A Step-by-Step Process to Install a Metal Roof Over Shingles
Installing a metal roof over shingles is a fantastic choice for durability and home value. Following these steps will help you properly install one.
Step 1: Install a Quality Roofing Underlayment
Start by laying down a protective barrier to prevent moisture from reaching the roof deck. Roll out a synthetic underlayment or 30-pound asphalt-saturated felt. Start at the bottom edge of your roof. Overlap each subsequent row by at least six inches to create a watertight seal across the entire surface. Secure the underlayment with cap nails for stability.
Step 2: Place Furring Strips for Airflow (Optional)
This step can greatly improve your roof’s performance. Furring strips create a vital air gap and allow ventilation and moisture to escape. It also provides a flat surface for the metal panels. Install 1×4 wood strips from the eave to the ridge. Align them with your roof rafters to make installing a metal roof over shingles easier.
Step 3: Confirm Roof Measurements and Panel Layout
Precision is everything when it comes to roofing. Double-check your initial roof measurements during installation. Plan the layout of your metal panels carefully. This helps you minimize waste and cutting errors. Start from one end and work across the roof. A proper layout ensures a professional and weather-tight finish. This step is critical before you cut any metal roofing material.
Step 4: Precisely Cut the Metal Panels
Now it’s time to size your metal panels. Use your measurements from the previous step. You can use aviation snips for smaller cuts. However, electric metal shears work best for long and straight cuts.
Always wear safety glasses and gloves during this process. Cutting metal panels generates sharp edges. Taking time for this step guarantees a perfect fit and a much cleaner final appearance.
Step 5: Securely Fasten the Panels to the Roof
Begin fastening the first panel along the gable edge. Ensure it is perfectly square and plumb. Use gasketed roofing screws to secure the panels. Place screws as recommended by the manufacturer, typically every 12–24 inches.
Drive them through the flat part of the panel. Do not overtighten the screws. You want the gasket to seal without being crushed. This is a key part of installing a metal roof over shingles.
Step 6: Install Flashing and Edge Trim
Flashing is essential in avoiding leaks. Make sure you have flashing in the valleys and around the chimneys or skylights so that the water flows in the opposite direction of the vulnerable areas. Gable edge trim and eave trim give your roof a clean and finished appearance and add protection against the weather. This is the crucial step that renders your roof waterproof to the elements.
Step 7: Finish by Attaching the Ridge Caps
The last step is the ridge cap. This piece covers the peak where the roof planes come together. Apply a continuous bead of sealant and then apply the cap. This provides a complete waterproof seal on the very top. Clamp the ridge cap on top of the metal panels. Your new metal roof will now be finished and will take care of your home.
Conclusion
Installing a metal roof over shingles follows a logical process: a moisture barrier, underlayment, furring strips to allow air to pass through, precise measuring, cutting, fitting panels, gluing, flashing, and edge trim, and finally, a ridge cap to complete the work.
Although it is a long process, it is worth it. But when the job is too big, it’s wise to hire professional roofing services. It is always good to use professional roof installation services to ensure that the job is done flawlessly.
