Can You Put Solar Panels on a Metal Roof?

Can You Put Solar Panels on a Metal Roof

Can You Put Solar Panels on a Metal Roof? The answer is Yes, you can put solar panels on a metal roof. Metal roofs are compatible with solar panels and can provide benefits such as increased energy efficiency, tax credits, and a longer lifespan for both the roof and the solar panels

Some important considerations when installing solar panels on metal roofs differ from installing on shingle or tile roofs.

Another frequently asked questions is: Can you Put Tesla Solar Panels on a Metal Roof? The answer is yes you can.

This guide will cover everything you need to know about installing solar panels on a metal roof.

Key Takeaways for Installing Solar Panels on a Metal Roof

  • Metal roofs require mounting equipment different from shingle roofs to prevent leaking and rusting. Use standing seam clamps or floating mounts.
  • The angle and direction the metal panels run must be considered when positioning solar arrays.
  • Reflectivity from the metal can impact solar panel performance if not accounted for. Add tilt to panels.
  • Work with a reputable solar installer familiar with metal roofing. Get roof manufacturer approval.
  • Inspect the roof for corrosion and leakage before install. Solar adds weight.
  • Proper sealing and anti-corrosive measures must be taken where attachments meet metal.

Assessing If Your Metal Roof is Right for Solar

The first step is determining if your metal roof is well-suited for solar installation. Here are key factors to consider:

Type of Metal Roof

  • Standing seam metal roofs are ideal for solar arrays. The vertical seams allow clamps secured to the seams to hold panels in place. This prevents roof penetrations.
  • R corrugated metal panels require different racking but can work. The corrugations run horizontally, so water sheds to the sides.
  • Aged or degraded metal roofs or those with pre-existing issues are not good candidates. Solar adds weight and stress.

Roof Pitch and Direction

  • Steeper-pitched metal roofs above 6/12 allow gravity to quickly pull water and debris down. Flatter roofs hold moisture and dirt longer.
  • Which direction the roof slopes and the corresponding direction of sun exposure impact solar efficiency? Aim for maximum sunlight.

Age of Roof

  • Older metal roofs are more prone to rust, corrosion, and fatigue. Inspect carefully before installing solar arrays, which add weight.
  • Newer standing seam metal roofs often come with manufacturer warranties of up to 50 years. Excellent choice.

Contact Roof Manufacturer

  • Consult your metal roof manufacturer early for warranty considerations and approval. Some provide detailed solar installation guides.

Once you’ve confirmed the suitable roof condition and type, it’s time to focus on proper solar equipment selection and placement.

Choosing the Right Solar Mounting System

Mounting solar panels on a standing seam metal roof is straightforward, utilizing seam clamps secured to the vertical seams without penetrating the roof. 

Other metal roof types require different approaches to avoid leaks and rust.

Standing Seam Clamps

Clamps attached to the raised seams are the most secure and non-invasive mounting method. The panels float securely above the surface. This is ideal for metal.

R Panel Floating Mounts

For corrugated or R-panel roofs, floating mounts that distribute weight across multiple panel points are needed. Attachments only where necessary.

Avoid Direct Mounts

Never use direct mount attachments that screw through the roof surface. These are prone to leaking and rust over time on metal roofs.

Work closely with your solar installer to select proper mounting equipment for your roof type. The last thing you want is to install an array that eventually damages your roof.

Solar Panels on Metal Roofing

Positioning Solar Panels on a Metal Roof

Proper placement on the roof is key once you’ve selected the mounting system. Here are tips for ideal solar panel positioning:

Angle Panels for Optimal Sun Exposure

  • Determine the direction of your roof slopes and angle panels to maximize sun exposure for your geographic location and climate.
  • Adjust tilt 5-15 degrees steeper than latitude for winter optimization.

Run Perpendicular to Seams

  • On standing seam roofs, run panel rows perpendicular to seams to span multiple anchoring points.
  • Avoid weighting seams unevenly or only attaching to high points.

Allow Airflow Under Panels

  • Leave 2-3 inches between the roof surface and the underside of panels for airflow. Prevents moisture buildup.
  • Floating mounts provide ideal airflow.

Consider Reflectivity

  • Beware solar efficiency loss from metal roof reflectivity. Tilt panels 5-20 degrees more upright to compensate.

Proper solar panel placement leverages your specific metal roof characteristics for optimal solar collection.

Protecting Against Rust and Corrosion

One major factor unique to metal roofs is the potential for rust and accelerated corrosion where attachments meet the roof. Use these tips to prevent issues:

Use Non-Penetrating Racking

  • Standing seam clamps and floating strut mounts avoid penetrating outer metal skin where water can intrude.

Isolate Mounting Points

  • Use nylon washers or butyl rubber tape barriers to isolate attachments from direct metal contact. Prevent galvanic corrosion.

Seal Penetrations Thoroughly

  • Where attachments are unavoidable, use premium butyl sealant between bolts/screws and roof. Seal all entry points.

Maintain Airflow Under Arrays

  • Let air circulate under panels. This keeps metal dry and avoids trapped moisture/debris.

Check for Snow and Ice Buildup

  • Clear heavy snow/ice from panels quickly to limit freeze/thaw cycles accelerating corrosion where mounts contact with the roof.

Proper mounting methods and corrosion prevention measures will keep your roof protected and solar arrays secure.

Hiring an Experienced Installer is Key

The best way to ensure proper solar installation on your metal roof is to hire an experienced solar contractor familiar with metal roofing. Here’s what to look for:

Experience with Metal Roofs

  • Ask about past metal roof solar installs. How many? What types? Any issues?

Familiar with Roof Manufacturers

  • Do they know your specific roof brand’s installation guidelines? Have they installed this type before?

Provides Complete Water Sealing & Isolation

  • Rubber barriers, butyl sealing, and nylon washers should be standard practice. Visually verify.

Includes Roof Inspection & Warranty Details

  • A roof inspection for leaks/corrosion should be standard before installation. Understand warranty impacts.

Has Premium Mounting Equipment

  • Name brand standing seam clamps floating mounts, and avoid direct penetration mounts.

Always hire quality installers for worry-free solar arrays on your metal roof versus the cheapest bid. Your roof’s integrity over the long haul depends on proper solar integration during installation.

Solar Panel on Commercial Metal Roofing

Inspecting Your Metal Roof Before Installation

Before moving forward with solar installation, a professional roof inspection is highly recommended. Here are the steps:

Check for Existing Leaks

Inspect roof panel seams and joints for any existing moisture entry and leakage points. Seal any found before adding solar equipment.

Look for Corrosion Signs

Check metal surfaces and seams for any visible corrosion or rusting. Determine cause and remedy before adding solar.

Verify Structural Soundness

Check for dents, damage, or areas of weakness that could compromise roof integrity when adding solar panel weight.

Review Age & Warranty Terms

If the roof is aging or out of warranty, consider overlaying metal panels vs. installing over questionable surfaces.

Document Condition

Take photos capturing pre-install condition. Useful for warranty claims and protects against liability.

Addressing roofing issues proactively will provide a sound foundation for solar installation and avoid headaches.

Weight Load Factors on Metal Roofs

An important reality with metal roofs is that solar arrays add significant weight that the roof structure and sheathing must support. Here are the key considerations:

Check Roofing Manufacturer Weight Ratings

  • Consult manufacturer specs for recommended weight limits per square foot for your specific metal roof profile and gauge.

Include Weight of Racking System

  • Often, 25 lbs per square foot minimum. More with heavy clamps or ballasted mounts.

Calculate Total Solar Array Weight

  • Add ~4 lbs per square foot for panels alone. More for glass/framed panels.

Reinforce Roof Structure if Borderline

  • If the total planned array approaches the limit for the roof, reinforce the roof from below before installing.

Add Supports Under Array for Distributed Weight

  • Set panels over solid underlying purlins/rafters. Avoid weighting fastener points.

Staying within recommended weight limits and accounting for added solar stresses prevents roof overload.

Impact of Solar Panels on Metal Roof Warranties

Metal roof warranties vary widely, from 10 years to lifetime coverage against leaks, finish failures, and structural defects. Adding rooftop solar equipment creates potential warranty complications.

Understand Original Warranty Terms

  • Review warranty coverage, solar exclusions, amendments required, etc., before installation.

Contact Manufacturer Before Install

  • Get written approval for specified solar mounting method, equipment, layout, etc.

Use Only Approved Mounting Systems

  • Stick with manufacturer-recommended solar attachment methods to stay in warranty.

Amend Warranty if Needed

  • Some metal roof warranties can be amended to cover solar for a fee.

Keep Good Documentation

  • Photos, roof condition report, manufacturer approval, installer contract, etc.

Proper planning and coordination with the roof manufacturer helps preserve the original warranty or secure proper coverage.

Solar Panel Maintenance on Metal Roofs

While solar arrays require little routine maintenance, metal roofs require occasional upkeep to maximize roof and solar system lifespan.

Periodic Inspections

  • Inspect mounts, seals, and contact points a few times per year for any issues. Address immediately.

Re-seal Penetrations

  • Check and re-apply sealant around any attachments penetrating the roof surface if drying out.

Check for Snow and Ice Buildup

  • Heavy snow or ice that stays for a while can accelerate corrosion under panels. Clear buildup promptly.

Clean Debris from Panels and Roof

  • Gently clear leaves debris from panels and roof surfaces to allow drainage and drying.

Catch Minor Roof Damage Early

  • Fix any emerging rust spots, fastener pops, or roof damage immediately before expanding.

Staying on top of preventative maintenance keeps your metal roof and solar arrays in shape for maximum ROI.

Bottom Line on Installing Solar on a Metal Roof

Installing solar panels on a metal roof can provide excellent solar generating capability when done correctly. 

The critical requirements are using non-penetrating seam clamps or floating mounts, consulting the roof manufacturer, hiring experienced installers, taking corrosion prevention steps, and doing periodic maintenance.

Following the recommendations in this guide will help ensure your metal roof solar array provides maximal, trouble-free solar energy production for decades to come. The initial planning and preparation pay off over the long run.

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