Can You Install a Metal Roof Over Shingles?

If your shingle roof is getting old and needs repairs, and you’re thinking about switching to metal but aren’t sure, here’s some good news for you. You can install a metal roof over shingles. It is long-lasting, good for the environment, and looks great too!

Setting up metal roofs over shingles is usually a completely safe idea. This should not be a problem as long as the roof is not too heavy and is in good shape. Even though you probably shouldn’t try to put a metal roof on your own, we’ll tell you what to expect.

Can You Install a Metal Roof Over Shingles?

Under the right conditions, you can put a metal roof over shingles. Your shingles must be nearing the end of their life if they are rough, raised, cracked, or blistering. It is not advisable to use a metal roof overlay if your shingles are in good shape.

You can install a metal roof over shingles without issue, as long as you do it correctly. By choosing not to remove your old asphalt roof, replace your underlayment, or pay to have the old roofing materials disposed of, you can save up to 25% on labor expenses.  

Although this sounds fantastic, most roofs are not suitable choices for installing a new metal roof over the shingles. 

How Does Installing Metal Roofing Over Shingles Work?

There are a few considerations to make if you decide to install metal roofing over shingles. Ensure that you resolve any current roof leaks and swap out any rotting sheeting or rafters.

Inspect the old roof to catch any indications that the old roof is overly heavy. Signs might include sagging decking or buckling tresses. You should also take note of the following things:

Manufacturer Specifications and Warranty

Even with the finest warranties, finding someone to inspect your roof and issue a check for any damage after 40 or 50 years could be challenging. Depreciation will also result in a significant decrease in the amount you receive. For this reason, it’s wise to get the highest-quality material you can afford, have it installed correctly, and adhere to the manufacturer’s requirements. 

Trim

The trim on your roof is the most noticeable feature when it comes to aesthetics. Flashing is required around all edges to improve the look and give protection from wind, rain, and snow. Getting ice guards is a good idea if you don’t have gutters. Make sure you have someone on the ground looking up the trim for you if you’re doing it yourself.

Fastener Application 

In order to ensure a visually appealing roof, the screws should be installed according to the manufacturer’s instructions, which call for them to be placed in the steel’s flat rather than its ribs. Moreover, screws function far better than nails, so try to avoid using them. To ensure that you don’t drill any more holes in your roof than necessary, place the screws every 24 to 30 inches apart and skip every other rib.

Safety

It should go without saying, but wear gloves! It’s a simple method of keeping your hands safe from wounds. If it’s windy, avoid climbing onto the roof as well. Keep the steel facing away from you if there is a slight breeze to prevent being blown over.

Steps to Installing a Metal Roof Over Shingles

1. Examine Plywood

It’s crucial to check the quality of the plywood underneath the asphalt shingles first. It is imperative to address any rotting or rusting before constructing a new roof. It is okay to proceed if it is in excellent condition.

2. Install a Synthetic Underlayment

By installing underlayment, you can prevent the asphalt shingle granules from eventually rubbing against the new metal roof, which might lead to damage. We advise utilizing synthetic underlayment as it won’t rip when the metal roof expands and contracts, even though the majority of underlayment is made up of felt-like material.

3. Incorporate Insulation

You can add a protective layer between the metal roof and the existing asphalt roof by placing E-foil insulation on the underlayment. By deflecting heat away from the roof throughout the summer, this layer can help improve energy efficiency.

4. Install Corrugated Metal Panels

This is the last step in the process of installing the roof. Corrugated metal, which facilitates air movement and natural venting, is the ideal material to use with e-foil insulation.

Advantages of Metal Roofs 

• Because of their reputation for endurance and curb beauty, metal roofs are becoming more popular with homeowners.
• They have a far longer lifespan than shingles. Depending on the material used, they can actually endure for 40–70 years.
• They will keep your house dry, cozy, and safe during practically every kind of weather. Both snowmelt and rain will be able to flow off with ease and speed. They can withstand wind gusts of up to 140 mph as well.
• Many of them can even weather hailstorms without becoming damaged. They can resist fire, be it from a lightning strike or a wildfire.
• They are available in different colors and textures, including the colors of natural cedar shakes.
• Through the reflective quality of solar radiation, they can increase your home’s energy efficiency and save your cooling expenses by 10–25%.

Advantages of Installing Metal Roofs Over Shingles

• It is less expensive than having an old roof removed. The disposal of asphalt shingles requires renting a dumpster and paying disposal fees, which is quite an expense.
• When you keep the layer of asphalt shingles intact, the roof becomes better insulated, which reduces energy costs.
• It gets rid of the necessity to tear off the current shingles. It takes about hundreds to thousands of dollars to remove old shingles. In addition to that, it takes a lot of work.

Disadvantages of Installing Metal Roofs Over Shingles

• When you add a metal roof to the shingles, you reduce the load that the roof can support. Even though the weight might not be significant enough to cause problems, it is something to consider, particularly for roofs that get a lot of snowfall.
• Taking off your old asphalt shingles means you can examine the roof’s state. However, if you install a metal roof without removing the shingles, you’ll miss your chance to detect any decaying or damaged areas.
• An uneven roof may result from outdated asphalt shingles that have inconsistent quality. This might make it difficult to install a metal roof on top of it effectively.

Conclusion

In conclusion, a metal roof may be installed over shingles. To decide if the shingles can withstand the weight of the metal roofing materials, it is crucial to speak with a qualified roofing contractor and evaluate the state of the shingles. To guarantee adherence to any prerequisites or limitations, it is also advisable to take into account the building rules and laws in the area.

We know everyone is on a tight budget, but installing a new roof is a significant expense, regardless of the circumstances. Hence, you should always begin with clear decking and replace all of the essential roofing elements to acquire the highest quality roof possible. 

All that being said, you still need to decide. We wish you good luck with that.

Frequently Asked Questions

Do I need an underlayment for a metal roof over shingles?

No, you don’t. But only in the event that the shingles are highly intact. You don’t need to install an underlayment over shingles if your shingles are in excellent condition before installing battens or metal roofing. It keeps leaks from getting too bad by aiding in moisture absorption. 

What is the best way to install a metal roof over shingles?

There are two preferred methods for installing metal roofing over shingles. The first step is to cover the existing shingles with an authorized underlayment. Although it is the quickest method to install, this method does not offer the flattest surface for installing metal roofing. Installing 1×4 purlins over the shingles is the second method. Although it costs more, the quality will also be better.

What is the advantage of a metal roof over shingles?

The installation of metal over shingles has a few advantages. One advantage is that it keeps the shingles out of landfills and saves you money on labor expenses associated with removal. The second is that the additional layer of shingles adds to the insulation of your house. 

Is it cheaper to get a metal roof or shingles?

Installing a metal roof over shingles will undoubtedly cost you money. Metal roofing could end up being more cost-effective in the long run, even though shingles are still less expensive. Their strength allows them to last for many decades, in addition to their stunning and distinctive appearance. In your lifetime, it’s highly likely that you won’t need to buy another roof.