Extremely durable and of natural beauty, slateroofshave long set the highest standard for roofing materials. Slate is nearly permanent. When properly cared for, a slate roof can last up to a century or two. As a natural stone, slate can withstand these years of weather without deterioration while preserving the rest of the home. Synthetic slatecanopyshould be considered together with natural slate. Synthetic slate offers a similar look but has cost and installation advantages not found in natural slate.
Slate roof shingles are made from natural stone that is extracted directly from the earth. One of the oldest types of roof tiles, slate tiles are durable, waterproof and insect proof. Slate is one of the most expensive roofing products on the market. Howterracottaormetal roof, Slate roofing is made entirely of inorganic materials, so the shingles will never rot or decay.
Most slate shingles for homes are either random width or constant width. Random width shingles contribute to a more natural, informal look and are available in at least two different widths. Constant width slate shingles give the roof a more formal, uniform look and use one width for the entire roof.
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Slate shingles range in size from 8" x 6" to 24" x 12". Slate shingles are typically about 1/4 inch thick. Some slate shingles are available up to 1 inch thick.
No one elseRoof material holdsas long as slate. The life expectancy of a slate roof is between 50 and 200 years.
For comparison: asphaltroll top, suitable forshed and outbuildings, can last up to a decade. Composite shingle roofing, the most common roofing material for residential buildings, can last up to 30 or 40 years. Only clay or cement roofs can match the durability of slate, with an expected lifespan of up to 100 years.
| Roofing material | Estimated Lifespan |
| asphalt roll roof | 5 to 10 years |
| Composite shingle roofing | 15 to 40 years |
| Wooden roof covering | 35 to 40 years |
| Metal roofing | 30 to 50 years |
| Clay or cement roof covering | 50 to 100 years |
| Slate roofing | 50 to 200 years |
Look
The unique shine of the slate roof comes from the high percentage of mica in the stone. This brilliant mineral makes slate shine when viewed from certain angles.
The other distinctive feature of slate is its roughly hewn appearance. Because slate is a sedimentary rock, it is made up of many layers that split or intersect, like the individual cards in a deck of cards. A type of slate called structural slate has uneven thicknesses of shingles with rounded edges.
environmental qualities
Longevity contributes to the environmental qualities of slate. Slate can withstand multiple cycles of composite roofing. On average, composite shingles must be removed and replaced every 25 to 30 years.
As a petroleum-based product, composite shingles are largely disposed of in landfills, with few being recycled.Slate shingles in good condition can be reused as shingles or ground up and used in other applications.
Weight
Slate weighs two to three times more than composite shingles. Traditional three tab composite shingles weigh about 250 pounds per square (per 100 square feet), with some premium architectural grade composite shingles weighing about 450 pounds per square. The roof systems of most homes are designed to support this weight.
What is a roof angle?
Roofing materials are usually quoted in units of 100 square feetQuadrate.
In contrast, natural slate shingles weigh between 675 and 1,870 pounds per 100 square feet, a weight that some roofing systems cannot support. It's important to consult with a qualified contractor or structural engineer before slating a home.
Cost of slate roof
| roof size | Low Estimate | High estimate | average cost |
| 1,800 square meters | 21.000 $ | 52.500 $ | 36.750 $ |
| 2,300 square meters | 26.000 $ | 65.000 $ | 45.500 $ |
| 2,750 square meters | 31.000 $ | 77.500 $ | 54.250 $ |
| 3,000 square meters | 34.000 $ | 85.000 $ | 59.500 $ |
| 3,250 square meters | 37.000 $ | 92.500 $ | 64.750 $ |
*All amounts include 10% offcuts and are rounded up to the nearest roof square.
As with any other premium roofing product, the cost of slate roofing is high. Expect to pay at least $1,000 per square of roof up to $2,500 per square depending on where the home is located, including the roof configurationroof pitch, and the size of the house.
A 2,300 square foot homeThe slate roof costs between $26,000 and $65,000. The average cost to install a slate roof on this home is about $45,500.
maintenance and repair
Although slate is very hard, it is also brittle, that is to saySlate can crackin the event of a strong impact. Falling branches that may just dent composite shingles will break slate shingles.
Slate roof repairs must be performed by qualified professionals, if only because slate is so difficult to walk on without damaging the slate or causing the worker to slip off the roof. A support system is required when working on a slate roof.
Additionally, slate repairs are difficult because there are so many variations of slate. Finding and mixing suitable substitutes for this natural product can be difficult.
Slate roof designs and styles
Structural slate roof
A structural oneslateThe roof has the look of the classic slate roof with a rough, textured and natural look. The texture adds depth and visual interest to the shingles. Although most slates are difficult to walk on, a textured slate provides the best grip on any slate surface.
Standard slate roof
A standardslateRoof has the opposite appearance of a textured slate roof. The shingles are flat, smooth and uniform in color and appearance. The clean, elegant look of standard slate shingles complements modern architecture.
Multicolored (mixed) slate roof
Multicolored (mixed) slate roofs mix different colors to create a unique and eye-catching look. Grey, green, black and purple tones combine to form a harmonious palette. Multicolored slate roofs have a distinctive yet natural and organic look that will enhance most homes.
slate roof assembly
Slate roof installation is not a do-it-yourself project. In general, roofing is only a project for the most experienced handyman, and slate laying is a highly specialized subset of roofing that requires specific tools not available to DIYers, such as nail holes.
Slate must be properly graded, sorted, and blended to ensure a consistent look and quality throughout the roof. Slate shingle roofs require installers experienced in working with slate. This means that not all areas have companies that can install slate shingle roofing.
Top brands for slate roofs
Most slate roof shingles come from quarries in New York, Pennsylvania, Vermont, and Virginia. Some quarries sell slate directly, while most sell through dealers.
- Glendyne, Inc.: Quarry based in Quebec, operating the largest slate quarry in North America
- Newmont Shale Company: based in Vermont, the largest roofing slate producer in the United States
- New England slate: Vermont-based dealer of slate shingles, all guaranteed for 75 years
- Vermont Slate Company: Georgia based manufacturer and distributor of approximately 20 lines of high quality slate shingles
Natural slate vs. synthetic slate roofs
Synthetic slate roofs create the look of slate roofs without the weight, cost, and installation difficulties of natural slate.
Made from up to 80 percent old tires and other thingsPost-Consumer-Gummiprodukte, artificial slate roofing is one of the more environmentally friendly products you can use. It has the textured appearance of slate and is evenly thick without many of the disadvantages of real slate.
Recycled rubber slate shingles are not fireproof, but are considered fire resistant. Where natural slate shingles tend to crack, slate shingles are very flexible and rarely crack. Synthetic slate shingles cost about $800 to $1,200 per 100 square feet.
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An alternative to natural and synthetic slate is hybrid slate. This composite, which contains real slate, is much lighter than crushed slate and costs about $1,000 to $1,600 per square foot.
Is a Slate Roof Right for You?
Homes with a classic but casual look benefit from a textured slate roof, while modern homes or stately older homes are best paired with standard slate. Slate roofs are suitable for homes in temperate or cold climates because slate is not considered a cool roof.
Because a slate roof costs up to three times the price of a traditional composite roof, it is best suited for homeowners who can afford this expensive project. However, if you expect to stay indoors for over 30 years, the high cost of the slate roof will pay for itself, resulting in lower annual costs over the long term.
Article Sources
The Spruce uses only quality sources, including peer-reviewed studies, to support the facts in our articles. Read ourseditorial processto learn more about how we fact-check our content and keep it accurate, reliable, and trustworthy.
The repair, replacement and maintenance of historic slate roofs. Nationalparkdienst (USA)
(Video) Real Slate Roof VS Synthetic Slate Roofing Shingles ComparisonRecycle plastic and rubber roof shingles. Nationalparkdienst (USA)
Highlights of 2021 Properties of new apartments. US Census Bureau
Cool roofs. Department of Energy (US)
FAQs
What is a drawback of a slate roof? ›
Cost: Slate roofing is one of the more expensive roofing materials on the market. A fully installed slate roof will cost at least two or three times more than an asphalt shingle roof, if not more.
Is slate roof worth it? ›While a typical asphalt roof should last for about 20 to 30 years, a slate roof should last 50 to 200 years. For those who don't want to reroof in their lifetime, slate's an appealing option. Slate is also a natural material and remains recyclable for other applications after its use atop your home is complete.
What are 2 reasons for slate roof failure? ›- Poor Quality Nails Were Used.
- Walking Over the Roof Tiles.
- Choosing the Wrong Flashing.
Jenkins said that in most cases, leaks in slate roofs are caused either by broken or missing tiles or faulty flashing.
Is slate hard to maintain? ›Slate is a very low maintenance flooring. All it requires is regular sweeping to keep it clean. The rough texture and varied coloring of slate tile flooring makes it a very forgiving flooring material.
Does slate crack easily? ›If you are looking for a durable floor material, slate in any reasonable thickness will not easily split or crack. Slate can split when exposed to very high temperatures. For example, some slate may crack if a very hot fire is lit directly onto the slate.
Do slate roofs crack? ›One of the major disadvantages of a slate roof is that it can crack under pressure when someone walks on it. This makes it difficult to perform maintenance and repairs. If a significant amount of shingles need to be replaced, it may be in your best interest to replace, rather than repair the roof.
Does slate roof increase home value? ›Slate is specifically designed to withstand elements like temperature extremes, fire, ice, and wind. It's also resistant to moisture and mold growth, so you don't have to worry about dangerous issues developing any time it rains. This translates to a higher home value than a comparable house with an asphalt roof.
Is it OK to walk on a slate roof? ›Slate is hard-wearing and durable but it can easily crack under pressure. That's why professionals use hook ladders, jacks and planks on slate roofing. This allows them to walk on the roof without putting any weight on it. If you don't have the proper materials on hand, it's best to let a professional tend to the roof.
Do slate roofs get hot? ›There's no doubt that roofing slates are good insulators under many different climatic conditions. I have seen slate roofs in the temperature range from about -30 °C (or -22 °F) in Norway to 40 °C (or 104 °F) in Spain, working without problem.
What is the lifespan of a slate roof? ›
A Slate Roof Is a Solid Investment
A hard slate, such as a purple slate or a grayish-black Buckingham slate, can last 150 to 200 years. But even softer slates have a life span of 75 to 90 years. So even though a slate roof might cost a little more to install, it can be an excellent investment.
Slate roofs are among the most appealing and common of all historic roofing types. Known for their handsome looks and durability, they give any property an aesthetic lift. If you want this option for your house, remember that you need to vent a slate roof just like every other type of roof.
What is the life expectancy of slate roof tiles? ›Slate roofs are often touted as 'forever roofs' and for good reason with a life expectancy of 75 – 100 years.
Are slate roofs noisy? ›'Chatter' in high winds is an unavoidable phenomenon associated with most roofing tiles and slates. The sound, which can be heard within the building, is caused by the tails of the tiles or slates being lifted and then dropped by the wind forces.
Why choose a slate roof? ›Slate is naturally mold resistant, fire-resistant, and has a low water absorption capacity. Because slate tiles are heavy, they are not easily blown off by strong winds. Water, strong winds, and fire are the common causes of roof damage and cost homeowners a fortune in roof repair and maintenance costs.
Can slate roof be damaged by hail? ›Slate tiles may be punctured, cracked or broken by hail. Any of these conditions could be deemed functional damage if the damage is serious enough. Because slate is a sedimentary stone composed of layers, hail damage may appear as a slate with a portion of layers missing.
Should I replace slate roof with shingles? ›There's the initial cost of installation, long-term costs of maintenance, upkeep, and replacement. When installing a roof on a budget, the clear choice would be asphalt shingles. Asphalt shingles are much less expensive up front than slate tiles, and the labor and installation costs are also significantly lower.
What is the longest lasting roof material? ›Concrete, clay, and slate tiles have an average lifespan of 100 or more years. They are without a doubt the materials that last the longest but are also, bar none, some of the most expensive. Slate roofs are often called the “forever roof” because they can last seemingly forever.
How often does slate need to be sealed? ›Like most other natural stones, slate tile flooring requires sealing to aid in water repellency and prevent staining and scratching, and sealer should be applied on a yearly basis.
What happens if you don't seal slate? ›Unsealed slate tiles will react to everyday wear, water and other environmental factors in different ways: Where tiles aren't sealed at all or haven't been sealed properly, they are more likely to become dulled over time – and with more traffic, stained shoes and rain, they can become stained forever and need to be ...
Is slate mold resistant? ›
Slate Roofs Are Fire, Ice, and Mold Resistant
They are resistant to both fire and ice, keeping your roof and home safe from damage in the event of extreme weather or emergency. In addition, slate roofs are also moisture and mold resistant.
Also known as rust spots, oxidation can appear as spotted flecks of rusty colours on stone. This is a natural phenomenon that occurs when the natural mineral content of the stone is exposed to different types of weathering.
Does slate get hot in sun? ›Slate Can Handle Extreme Temperatures
This feature is one of the reasons it's such a popular stone to use on a roof. An outdoor slate tile surface or roof will keep the interior cool even when it's hot outside, because it doesn't quickly absorb the sun's heat.
If you live in cold or rainy climates, the freeze-thaw cycle will cause the water to expand in your stone and crack and shatter the slate.
What is the best roof to increase home value? ›The Remodeling Report for 2019 found that a metal roof, on average, cost homeowners $38,600 and increased home value by 60.9 percent. Compare this to their findings for asphalt roofs, where the average homeowner spent $22,636 and got a return of 68 percent.
Why are slate roofs expensive? ›Better quality materials are pricier, and the need for experienced roofers drives the cost of a slate roof significantly higher than that of conventional asphalt or composite shingles. Few homeowners will live long enough to enjoy the 100-year lifespan (or more) of most natural slate roofs.
What color roof increases home value? ›If you're someone who needs a more technical answer, this article explains that roofs with good resale value tend to be neutral-colored. This includes tan, brown, black, and gray.
Do you need a membrane under slate roof? ›If water gets underneath the roof tiles or slates, it could cause damage to belongings in the loft as well as severe structural damage, leaks, mould, and rot. Breathable roofing membranes will help to prevent the ingress of water and allow it to drain off the building rather than leak into it.
What is the minimum slope for a slate roof? ›Slate roofs typically need a minimum pitch of 17.5° to 20° depending on the construction of the slate and the area where the house is situated. This is because a shallow double lap roof uses a “headlap installation” technique, where multiple tiles are arranged in a manner to prevent rain from entering the house.
Are slate roofs nailed? ›Slate measuring 3/4” or more in thickness and 20” or more in length are usually secured with four nails each. The two additional nails are placed approxi- mately 2” above the regular nail holes. As slating is a craft, there may be some variance in nailing practices.
Is hard slate better than soft slate? ›
Hard slate is the strongest type regarding fire resistance and weather resilience. Its shingles are designed to last about 75-200 years. Soft is less durable but still has much better durability than other roofing materials. It can last between 50-125 years in most cases.
What color roof is coolest? ›White or light-colored roofs reflect heat rays from the sun, keeping the attic and rooms below it cool during warm weather. As a result, the building's cooling load decreases, helping home and business owners stay comfortable and save money on their energy bills.
What is the R value of a slate roof? ›Slate roofs have an R-value of anywhere between 100-150 depending on where they're installed and the type of shingle used. Slate roofs are known to provide insulation against both heat and cold, making them perfect for homes in cold climates as well as hot climates.
How often should a slate roof be cleaned? ›The Importance of Slate Roof Maintenance
Maintenance servicing includes gutter cleaning, inspections for damaged areas, and cleaning about three times annually. Slate roofs are delicate, and repairs can be costly, but quick action is vital to preservation and longevity.
Slate roofing is the top of the line when it comes to all-natural, extremely durable, and energy-efficient roofing. Lasting for over a century, slate tiles instantly add market value to a property and are a stunning feature for any home.
Are slate roofs better than tiles? ›Tiles are definitely a cheaper solution that come in a greater variety of colours and patterns, while slate has increased longevity and is perfect for bringing out a more rustic quality of your home. Whichever one you choose, however, they're both solid choices worthy of your investment!
Are slate roofs fragile? ›Fragility – Slate may look tough, but it is actually pretty fragile. If, for example, a tree branch fell on your slate roof, this could cause a lot of expensive damage. It may also be difficult finding replacement tiles that match perfectly.
Do old slate roofs contain asbestos? ›Asbestos-cement slate was mainly produced by the wet process, which results in a relatively low level of asbestos exposure. However, the problem of exposure to asbestos in the process of natural weathering, repair, or demolition of buildings using an asbestos-cement slate roof was still significant.
When did slate roofs stop? ›The peak of slate production was around 1900. Most of the original slate quarries in America now no longer exist. Only a few remain. Slate roofs declined in the early 1900s and new slate roof installations almost disappeared after 1940.
Is there a guarantee for slate roof? ›Slate roofs don't come with a material warranty
Remember, slate tiles are naturally made. Since it's a naturally mined roofing material, there's no manufacturer warranty on the slate tiles or the roof.
Can hail break slate roof? ›
Slate tiles may be punctured, cracked or broken by hail. Any of these conditions could be deemed functional damage if the damage is serious enough. Because slate is a sedimentary stone composed of layers, hail damage may appear as a slate with a portion of layers missing.
What causes slate roof to leak? ›Slipped Tiles/Slates
Bad weather can sometimes cause tiles or slates to slip off, leaving roof underlay exposed. Large quantities of rainwater can then pool in that area, making a leak increasingly likely to occur. The same thing can happen when slates/tiles crack or chip.
Required by many building codes, a slate roof's underlayment serves many purposes and application may vary depending on thicknesses of slate, weather conditions of the area and size of slate. Some key functions of a roof underlayment: Protects the roof and building until the slate is installed.
Do you need felt under a slate roof? ›It is common practice to introduce a layer of roofing felt under the slates when replacing whole roofs, but it is not essential and not recommended if the roof has been close boarded.
Is slate tile high maintenance? ›Slate is a very low maintenance flooring. All it requires is regular sweeping to keep it clean. The rough texture and varied coloring of slate tile flooring makes it a very forgiving flooring material.
Does slate fade in the sun? ›Weathering and Non-Weathering
Colored slate is never fading. However, it may weather with time due to the oxidation of it's embedded minerals. This causes the color of the tile to change over time, often towards buff, brown, gray or tan tones.