Cost to Install Metal Roof Over Shingles – Best Budget Guide 2021

Many homeowners realize the value of installing a metal roof over shingles - referred to as an overlay. With this method, metal roofing goes directly on top of shingles without having to tear the shingles off. 

In this best budget guide, we will look at the cost of installing a metal roof over shingles. We'll break down these expenses to cover DIY metal roof costs, the labor cost to install metal roof and the price of materials. We'll also talk about some typical metal roof over shingles problems.

Placing a metal roof overlay is cheaper than doing a tear-off, and it's easier and faster, too - especially for DIY'ers. We'll compare these costs below, so keep reading.

Average Costs of Installing a Metal Roof

Many people hesitate to install a metal roof because of the significant upfront costs. This option is more expensive than installing shingles. The size of the home in square feet, the type of metal used, and whether it was DIY or professionally installed can affect the final cost. 

However, the many benefits of metal roofs are strong persuaders that help sway homebuyers' decisions. Just from the lifespan alone, you see a maximum return on your upfront investment.

The average cost for installing a metal roof can range from $9,500 to over $40,000. This number includes materials, labor, and overhead (shipping of materials, contingency funds for unexpected expenses). 

This cost is steeper compared to installing a shingled roof, which can cost as little as $5,000 and higher than $11,000, costing $1 to $2 a square foot or $90 per square (100 sq ft). 

But wood, composite, clay, and asphalt shingles have a shorter lifespan of ten to twenty years, while metal roofs can last 50 to 70 years. In the long run, you get your money's worth by not having to replace your roof repeatedly.

Expenses

Professional

DIY

Materials

$8,000-$20,000

$5,000-$10,000

Labor

$3,000-$10,000

None

Overhead

$2,000 - $7,000

$2,000-$7,000

Costs of Materials

When compiling the costs of materials, we've included the prices for the metal - shingles and standing seam panels - and the cost of additional supplies needed for installation. 

Metal Shingles or Panels Costs

Types

Cost Range (a square)

Corrugated Sheet Metal Panels

$150-$250

Standing Seam Metal

$200-$1,000

Metal Shingles

$275-$600

Steel Metal

$75-$350

Stainless Steel Metal

400-$1,200

Corrugated Steel (Ribbed Metal)

$350-$700

Tin (Terne) Metal

$350-$1,500

Aluminum Metal

$150-$600

Zinc Metal

$600-$1,000

Copper Metal

$800-$1,500

Corrugated sheet metal panels are the most common style of metal roofs. These panels range from $150 to $250 a square and are usually 24" or 36" wide. 

Standing seam metal has a cost $200-$1,000 a square. These are long solid metal panels that hang vertically down your roof. 

Whereas metal shingles can cost between $275 and $600 a square. Premium stamped options go as high as $1,100-$1,200 a square (100 sq ft). 

The type of metal, finish, and style can also affect the roofing cost. Steel averages $75 to $350 per square, with stainless steel costing $400-$1,200. A more budget-friendly and popular option is corrugated steel (ribbed metal), which costs $350 to $700 a square. Rusted - Corten - metal costs $200 to $300 a square.

Tin (Terne) ranges from $350-$1,500 while aluminum runs $150 to $600 a square. Premium metals like zinc or copper panels have the highest cost of $140 a square. You can expect to pay anywhere from $600 to $1,000 for zinc each square and $800 to $1,500 per square for copper.  

The metal's thickness will also affect price, ranging from $1.75 to $7.00 a linear foot. The thicker the metal, the higher the price. You determine a metal's thickness by the gauge measurement, written as a number and ga (24ga = 24 gauge). Gauge measurements are opposite, so the smaller the number, the thicker the metal. 

Underlayment

All roofing requires a layer of underlayment between the decking and the metal. When installing a metal roof over shingles, you need a breathable underlayment, which will prevent the roughness of the shingles from damaging the metal. A roll of underlayment ranges from $165 to $220. 

How many rolls you'll need will depend on the size of your roof in square feet. Roofs with hips, dormers, valleys, ventilation, or complex configurations will require more underlayment to account for the various cuts. 

Decking

You might also have to include the cost of any decking or lumber that your project needs. For metal shingles, you'll need to install 2x2s or use a 4'x8' solid sheet decking like ⅜" OSB (Oriented Strand Board) or CDX plywood, which is an additional cost. 

These materials vary in cost by location, season, and thickness, ranging from $15 to $43 a sheet for OSB and prices starting around $22 for CDX plywood. 

When installing shingles, you may also have to purchase 1x4 purlins or 2x2 boards to lay over the roof to create a surface that's flat enough to mount the metal. 1x4s can range from $3.62 to $5.70 a piece, while a 2x2 starts at $4.25.  

Hardware

You'll also need to factor in the costs of the additional materials required to complete the install of your roof. Metal panels require screws and fasteners rather than nails to secure the panels in place to the decking. You can spend as much as $750 on enough premium threaded screws to complete the job.

Some metal shingles have built-in nailing strips. But some models will not, which means you will need to purchase nails rather than screws. It's crucial to use the same material for the nails as the shingles - aluminum ring-shank nails for aluminum shingles; galvanized roofing nails for steel shingles.

Equipment

If you're DIY'ing your metal roof install, you'll also need some equipment. You may already have some of this stuff in your workshop. But if you have to buy everything, it shouldn't cost more than a couple of hundred dollars. Most of these items are inexpensive. You will need:

  • Knee pads
  • Safety glasses
  • Utility knife
  • Hammer
  • Tin snips
  • Stapler
  • Chalk line

Plus, you'll also need a roofing harness for safety, a sheet metal locking tool, and roof jacks. These items will be more expensive, but you may be able to rent them at your local hardware store. 

Basic Installation Labor Costs

Installing metal roofing requires an experienced skillset, specialized equipment, and some heavy labor. These factors do influence the cost of having a metal roof professionally installed. 

The majority of roofing companies will charge by the square foot, with an average cost of $350 to $700 a square (100 square feet). Your costs will increase, depending on the size of your home, the type of metal, and your roofline's shape. 

You can spend anywhere from $5,000 up to $15,000 to install a metal roof over shingles when added together. This value range is for overlaying metal over existing shingles. Your costs will increase if you have to pay for a tear-off due to damaged shingles or the roofing structure.

Flat roofs will be cheaper than roofs with different angles or places where the metal needs cutting to fit around items like chimneys, skylights, or exhaust vents.

The costs for labor for a simple roof average around $3,000, while a complex roof can cost as much as $10-grand in labor fees for a professional install.

Unexpected Expenses

The price we've given you for the cost to install a metal roof over shingles includes materials, labor, and installation. However, any smart contractor will tell you always to have a contingency fund that allows for any unexpected expenses you might not have figured into your estimate.

While our goal for this article is to discuss the price of placing a metal roof over shingles, we also want to point out that there may be times when you may have to remove your shingles before installing a metal roof.

If your house already has two layers of shingles, there may be local or state regulations that require the roofers to remove one or both layers before adding the metal. If your roof has three layers of shingles, you can't install metal over the top until you've gotten rid of the shingles. 

The cost for the tear-off of old shingles can cost $100-$150 per square for a single layer, $150 and higher for a two-layer roof, and over $170 a square for triple-layer shingles.

If your roof has any signs of damage, leaks, or structural integrity issues, most contractors will require you to address these before installing a metal roof. Some cases may require replacing damaged pieces, such as decking, insulation, rafters, or joists. The cost of these repairs vary by the degree of damage and can cost anywhere from a couple hundred to thousands of dollars.

Price for Long-Term Maintenance and Repairs

Many people choose metal roofs for their durability, lifespan, and easy maintenance. Metal will be zinc (galvanized) or a mixture of zinc and aluminum (zincalume or galvalume), which will protect your roof from common issues like corrosion, rusting, and damage. 

Over time, this coating will start to wear off, requiring you to recoat the surface using a polymer coating to restore your roof's luster. The cost to reseal a roof can cost from $438 to $1,910, with an average price per square foot of $0.65 up to $5.

Metal can resist high winds, snow, hail, fire, and ice better than shingles, reducing the chances that your roof will need repairs during its extensive lifetime.

But freak accidents do occur that may cause your roof to need repairs. The cost of repairing a metal roof ranges from $175 up to $6,500, depending on the type of repairs done.

There is some metal roof over shingle problems that are more likely to cause the need for repair. The most common issue with metal roofs is leaking. This issue often occurs along protrusions (skylights or vents), seams, and where the roof planes change angles. The faster you detect leaks, the cheaper the repair.

Another metal roof over shingle issue can occur water vapor getting trapped between the two layers of roofing. This issue can cause rotting and mold growth, resulting in you having to replace your roof sooner than expected. The repair costs for this issue can cost thousands of dollars. 

How to Budget Your Roof Over Shingles Project

The best way to handle any home improvement project is by setting a budget and sticking to it. The biggest mistake people make when creating a project budget is underestimating the costs.

When planning a budget to determine the final cost of having an overlay of the metal done, it helps break the balance into categories. By setting a budget for each of these categories, you control the final cost.

However, you have to know what factors will go into each category. By reading this article and taking notes, you should have a strong understanding of how to factor in the different expenses for each type - there are three. Use the formula - materials + labor + overhead = total.

The first category, materials, will be a third of your budget. As we explained above, metal is not the only material you will need. You'll also need to figure up a budget for the decking, fasteners, underlayment, flashing, and any necessary equipment rentals or purchases.  

Labor costs should be another third of your budget. When dealing with roofing companies, get quotes from different businesses to find one with the most reasonable labor and materials rates.

The third part of your budget should cover your overhead costs. This category should include the price of accessories like gable edges, fasteners, valleys, drip edges, ridge caps, pipe flashings, and coatings. You should also budget a contingency fund of money to account for any emergencies that may arise.

FAQs

Q: Can you install a metal roof over shingles?

A: Installing a metal roof over shingles is a process called overlay, and it's an effective and affordable way to replace your roof without having to pay the high cost of a tear-off. 

Q: When would I have to use a tear-off instead of an overlay?

A: You can often use an overlay instead of a tear-off, but if there is damage to the shingles, the foundation, or the roofing structure, your existing roof will have to be torn off before you can add metal. 

Q: How many layers of shingles can there be to add a metal roof?

A: If your roof has more than two shingles layers, you may have to remove at least one layer of shingles before placing the metal. Some states may have a rule that will only allow for one layer of shingles or require a complete tear-off before installing a new roof. These rules are part of the 2018 International Building Code (International Code Council Series) Section 1511.3.1. 

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