How to Install Metal Roofing over Shingles? | Considerations and Approaches

Exploring the possibility of installing metal roofing over shingles can feel like stepping into a world of potential. Homeowners often consider this approach to upgrade their roofs without removing existing shingles. It also offers better durability and energy efficiency, making metal roofing an attractive option for protecting homes from the elements.

Many wonder about how to install metal roofing over shingles for its advantages over asphalt shingles. Durability, long-lasting protection, and eco-friendliness make this approach appealing. Removing the original shingles is optional if they remain in good condition.

Delve into this guide as we break down the considerations and approaches. We will discuss the pros and cons of installing metal over shingles and answer common questions. You will also learn about underlayment needs, furring strips, and compliance with building codes in Washington.

Pros and Cons of Installing Metal Roofing Over Shingles

Considering can you put metal roofing over shingles requires weighing advantages and drawbacks.

Advantages of Metal Roofs Compared to Shingle Roofs

• Better Durability: Metal roofs resist storms, wind, and extreme weather.
• Long-Lasting Protection: Asphalt lasts 25 years, metal can last 50+ years.
• Sustainable and Eco-Friendly: Metal is recyclable and enhances energy efficiency.
• Low Maintenance: Lower long-term maintenance compared to shingles.
• Lightweight: Adds less weight than other roofing materials when layered.

Drawbacks of Installing Over Shingles

• Increased roof thickness may stress structure.
• Poor drainage can trap moisture, causing mold or rot.
• Some warranties are limited when installed over old shingles.

Structural Integrity and Roof Condition

Check your roof framing before installation. Even though metal panels are light, adding shingles may stress older rafters. Inspect for sagging, water damage, or weak spots and reinforce or replace damaged wood.

Evaluate shingles for damage, curling, or missing pieces. Local codes may limit multiple layers. Minor repairs are okay, but structural damage requires removing shingles entirely.

Importance of Underlayment

Using do you need underlayment for metal roof over shingles is critical. It provides a second barrier against water infiltration and protects the roof deck. Synthetic or rubberized underlayment is highly recommended. Proper installation aligns with manufacturer guidelines and enhances durability, insulation, and soundproofing.

Metal Roof Installation Approaches

Purlins Attached to the Existing Roof Deck

Attaching purlins creates an air gap, reduces heat transfer, and provides a flat base for metal panels.

Underlayment Between Shingles and Metal Panels

Underlayment protects against moisture and damage from shingle granules. Options like fanfold or flute fill reduce heat transfer.

Building Codes and Furring Strips

Check local building codes before starting. In Washington, permits may be required and layer limits enforced. Ensure compliance to avoid fines.

Assess are furring strips required for metal roof over shingles. Furring strips lift panels, improve air circulation, and align uneven surfaces. Some areas mandate them for safety and code compliance.

Tools and Materials

• Metal roofing panels, screws, underlayment, furring strips
• Sealant, foam closures, ridge caps
• Safety gear: gloves, non-slip shoes, eye protection
• Tape measure, chalk line, metal snips, power drill
• Ladder or scaffolding

Step-by-Step Installation Guide

• Clear debris and inspect shingles.
• Install underlayment over shingles.
• Add furring strips if required.
• Snap chalk lines for panel alignment.
• Position and fasten metal panels with overlapping seams.
• Install ridge caps, side trims, and seal edges.

Maintenance Tips

• Keep gutters and downspouts clear.
• Inspect panels twice a year for loose screws or damage.
• Reapply sealant and tighten fasteners as needed.
• Trim overhanging branches.
• Treat rust spots with primer and touch-up paint.

FAQs

Can I install metal roofing over multiple shingle layers?

Yes, but local building codes may limit the number of layers. Inspect your shingles first.

Do I need special tools for metal roof installation?

Basic tools suffice, but a power drill, metal snips, and chalk line make the job easier.

Is underlayment always required?

Underlayment is recommended for durability, insulation, and moisture protection.

Do furring strips improve roof longevity?

Yes, they lift panels, improve airflow, and reduce corrosion risk.

How do I ensure code compliance in Washington?

Check local permits, layer limits, and fastening requirements before installation.

Making Informed Decisions

Installing metal roofing over shingles can save time and provide lasting benefits when planned carefully. By understanding the pros and cons of installing metal over shingles, using proper underlayment, considering furring strips, and following the building code for installing a metal roof over shingles in Washington, you’ll set your project up for success.

For expert guidance, visit How to Install Standing Seam Metal Roofing and Contact Us to start your project today. You can also explore Metal Roof vs Shingles and Types of Metal Roof to learn more about the best roofing solutions for your home.

With the right tools, solid preparation, and consistent maintenance, your metal roof will protect your home and enhance its value for decades. By following these steps, your project can be completed safely and efficiently, ensuring long-term satisfaction and performance.

Proper tools, preparation, and maintenance ensure your metal roof protects your home and boosts value for decades. With these steps, your project can succeed safely and efficiently.