Pros and Cons of Slate Roofs

slate roof

So you’ve seen how beautiful a slate roof is and want to have one installed on your house. Keep in mind that a slate roof is both a huge investment and undertaking, so it’s best not to act rashly. Knowing the pros and cons of slate roofs will help you determine if this is the right choice for you.

Choosing a roof type is not as easy as selecting the next movie to binge-watch on Netflix. Even if you have no issues with the installation, you’ll have to live under the same roof for many years, so choosing the right one is vital. Getting to know the advantages and drawbacks of a certain roof type is the quickest and most effective way to understand if it’s the right choice.

What is a Slate Roof?

Slate roofs have been around for almost forever. In the past, it was all about using natural stone without any additives. Slate roofs are quarried from the Earth, similar to natural granite countertops. Did you know that most of the raw materials used to manufacture a natural slate shingle actually formed between 450 million to 600 million years ago?

Today, a slate roof has evolved into a number of types. While some of their benefits overlap, the diversity allows homeowners to pick the slate roof type that matches their preferences.

From 1976 to 1977, using slate as a building material became very popular. Even to this day, homeowners in states such as New York, New Jersey, Ohio, and Pennsylvania continue to use slate for their roofs. And with quarries that produce slates dwindling to just a few in the United States, we’ve started to import slate roofing materials from other countries, such as China and Brazil.

Pros of a Slate Roof

slate roof
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Slate roofs have survived the test of time not just because of habit but because they continue to provide benefits that we still enjoy. Here are some of the pros of using slate roofs:

A Lifespan of More Than 100 Years

A well-cared-for natural slate roof can last for more than a century. When you compare it with wood or asphalt shingle roofs which last for up to 30 years, a slate roof is a great option knowing that there’s a chance you won’t have to replace your roof for as long as you live.

Real slate shingles are long-lasting because they have the natural characteristic of being resilient to high winds and extreme temperatures. A slate roof does not warp despite being exposed to moisture, nor does it absorb water. It can maintain its composition even in extreme cold or heat.

Eco-Friendly Solution

Being a natural stone product, manufacturing a slate shingle doesn’t go through too much processing. Compared to asphalt shingles or metal roofing, which require fossil fuel to create, a slate roof is a better option if you’re thinking about its impact on the environment.

Furthermore, since it takes a very long time before you’ll need to replace a slate roof, it significantly cuts down transportation emissions.

Elegant and Timeless Aesthetics

Not much has changed in the design of a slate roof – except for more variety in colors, texture, and shape. Its appeal is not restricted by time and fickle trends. Choosing to have this roof type installed on your home means you won’t have to worry about your home going out of style. And if you consider the fact that it can last for more than 100 years, having a timeless beauty becomes even more essential.

Low Maintenance

Slate roofs are an almost set-and-forget kind of thing. Once installed properly, you won’t have to worry about your slate roof except for regular checkups, which occur only annually. Since slate doesn’t warp, is invulnerable to rust, and is mold resistant due to its density, there’s no need to check the condition of your slate roof every so often.

Slate roof maintenance usually involves just checking for leakages, removal of accumulated debris due to ice formation in winter, and visual inspection for cracks.

Resistant to Fire and the Elements

Another reason slate is a great choice for a roof system is that it’s completely fire-resistant. Well, you would expect this characteristic from a material made from natural stone. It’s an ideal fireproof roof for those living in areas commonly plagued by wildfire and brush fires.

Even if you’re living in an area where it’s always humid, you won’t have to worry about mold or fungus because slate roof tiles are unaffected by these.

Energy Efficient

Thanks to its thick and dense panels, slate roofing can help take the load off your HVAC, which can result in lower energy bills. During the summer months, a slate roof can help keep your home cooler by preventing hot air from entering your attic and your home as well. On the other hand, your home doesn’t get too cold during winter because the same dense characteristic of slate roofing prevents warm air from escaping.

Cons of a Slate Roof

textured slate roof
Photo Credit: Siaron James / Flickr / CC BY 2.0

A slate roofing system is what most, if not all, homeowners would want for their roofs, but not everyone has this type of roof installed because of its drawbacks. Here are some of the major cons of a slate roof you should be aware of beforehand.

More Expensive Than Other Types of Roofing

All roof prices will still vary by the size of roof and roofing material used, but the upfront cost of a slate roof is still higher than other types of roof. And unsurprisingly, a natural slate roof is the most expensive roof material.

However, the hefty investment is justifiable by the benefits mentioned above, more so if you consider the fact that you never have to replace your roof again after installing a slate roof.

Heavier Material Requires Added Structural Support

The weight of a slate roof tile is what most homeowners consider its biggest drawback. On average, the combined weight of slate tiles per square foot can be up to 15 pounds. Just imagine how heavy a residential roof will be if there are 1,500 square feet of roof to cover.

Not all homes can accommodate and bear the weight of a thick slate roof. The great thing is that it’s not the end of the world in case your roof is not built to support slate. You can have your home retrofitted or have new framing installed prior to the slate roof installation.

A structural engineer will have to approve the retrofitting to ensure your home is safe. If you take this route, though, you can expect to pay high costs for the roof replacement.

Complicated and Specialized Installation

Because installing a slate roof is both complicated and labor-intensive, you should hire experts to ensure proper installation. Handling the fragile, yet heavy, tiles requires extreme care, which means the entire process can take a long time. It becomes even more tedious the steeper the incline of the roof.

Hiring master slaters, expert roofers, or specialized roofing companies translates to higher installation costs, but the outcome would be well worth it.

Vulnerable to Foot Traffic and Sudden Impacts

Slate tiles are indeed resistant to inclement weather and the elements, but they’re vulnerable to impact damage. If you’re going to have someone walk along your roof to install a satellite or fix your flashing, there’s a chance that some tiles might crack.

Foot traffic is not the only source of impact damage to your slate roof tiles. Falling tree branches and flying debris are also hazards. Cracks on your shingles could lead to leaks, and replacing them could be tough, especially if you can’t find a matching tile.

Types of Slate Roofs

Slate roof materials come in a variety of options. Manufacturers produce different types of slate roofs to accommodate varying preferences and situations.

  • Natural slate: This type of roofing material is the most expensive and the most durable. The tiles are made in a traditional fashion, quarried from the Earth. They are also the heaviest.
  • Concrete slate: A cheaper alternative to natural slate roofs, concrete slate inherits most of the characteristics of its traditional counterpart. The drawbacks? Concrete slate can last only for up to 50 years, and its composition makes it susceptible to mold and mildew growth.
  • Bituminous slate: This material is the closest to asphalt shingles because bituminous slates are manufactured almost the same way. The big difference is that bituminous slates have a smooth texture, while asphalt shingles are rough.
  • Metal slate: If you want more options for your slate design and color, metal slates offer the most choices. Metal slate can even mimic the design of natural slate. While metal slate is less brittle than the traditional version, exposure to extreme temperatures can negatively impact its integrity. Plus, it can get really loud inside your home during heavy rains or hailstorms.
  • Synthetic composite slate: This slate material seeks to eliminate most of the drawbacks of a natural slate, including the weight factor. It also can last up to 100 years and is not prone to breaking or cracking. If you’re OK using a synthetic slate instead of the traditional and natural one, this is a great choice.

Cost of a Slate Roof

Installing slate roofs can cost between $8,410 to $25,825, and your final price would depend on the size and shape of your roof. This doesn’t even count other factors which can add more to the total cost, such as:

  • The angle of the roof
  • Installation cost
  • Roof design
  • Additional materials, such as copper flashings and nails

High-end projects can end up costing as much as $45,000. The general rule is that roof size is directly proportional to the amount you have to pay.

How Do You Know if a Slate Roof Is Right for You?

Still not sure if you’re making a good decision by having a slate roof installed? Here are some crucial things you need to consider:

  • Can your house bear the weight of a slate roof? If not, you can have your roof retrofitted for an additional cost.
  • If you’re planning to move within five to 30 years, investing in slate roofing may not be a good idea.
  • Can you afford such a huge home improvement project?
  • Choose slate roofing if you prefer a timeless and elegant style that will last a lifetime.

You also need to find a local roofing contractor with the specialization and experience to install slate roofs.

FAQ About the Pros and Cons of Slate Roofs

Is a slate roof worth it?

With the financial and home structure considered, a slate roof is truly worth having. Once installed, you won’t have to think about installing a new roof for the next 100 years or so. Plus, a slate roof is virtually maintenance-free, as it requires only an annual inspection.

What is the biggest problem when choosing slate roofs?

Weight is the biggest issue as it not only requires homes that cannot support it to be retrofitted, but it also significantly adds to the installation cost. The additional framing, extra labor, and the cost of having a structural engineer approve the retrofitting can all add up significantly.

What are the common causes of slate failure?

Improper installation is one of the most common reasons for slate failure. Using substandard roofing nails or the wrong type of flashing can impact its performance and lifetime. Even if your slate roof is properly installed, foot traffic and falling tree branches can cause the slate tiles to crack, which can lead to leaks and costly roof repairs.

Confidently Decide If a Slate Roofing System is Right For You

With the information you learned about the pros and cons of slate roofing, you should now be able to confidently and intelligently decide if this is what you should use for your new roof. Knowing the advantages and drawbacks can help you get a better and more realistic picture of what to expect with this roofing option. Connect with your local roofing contractor near you and get your slate roof installation started.

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Melanie Joseph

After discovering her passion for writing through her beauty blog, Melanie left her engineering job in California, became a writer, and never once looked back. When she isn't writing, she loves dipping in the pool, tending to the garden, or doing simple home improvement projects.