A little less than a year ago we wrote a post (great comments by the way) that explained how the natural slate market was being damaged by the manufacturers of “synthetic slate” marketing their rubberized, polymer, shingle as “slate”. This is a disingenuous description of a rubber material because “slate” is defined as a natural rock. Big business is taking advantage, unfairly, of a high end roofing material and leveraging the name for profit.
Let’s be real clear, this is not slate. This post is not saying there isn’t a place for this type of material (Where? I’m not sure), it just shouldn’t be called slate.

Notice the fading color after only 5 years. The color underneath is what is started as, and now the sunlight has faded the non-covered area.
Fact Checking Synthetic Slate
Quality – If “artificial” slates are not stored flat and become twisted or curled, lay them flat in a warm place and they will return to their original flatness. Pg 9 of this PDF
Anyone who knows slate should immediately shake their head at the material being installed on a roof. This sentence came from an installation guide for synthetic slate and should cause shivers to any homeowner knowing that their roofing material can curl before it even comes out of the box. What do you think is going to happen when wind gusts and high temperatures are pulling it at it on a daily basis? This is what is going to happen which will rely on underlayment to protect a roof.
Cost – It is simple to install and at a fraction of the weight and cost of natural slate roofing.
Fraction of the weight? Yes. It should be mentioned that the cost to install synthetic is considerably cheaper because of the weight of the material (easier to transport) and the ability to nail with a nail gun instead of a hammer. The actual cost of the material though is similar. In order to get a Class A fire rating in synthetic slate material, you’ll need to spend upwards of $500 a square for their premium material. A typical square of slate is around $350-500, depending on size. The reduction in installation costs initially is easily outweighed by the longevity of a natural slate roof and it’s not even close. Here is an older article outlining the cost which shows a rubber roof with a 90 year expectancy and that is not correct. A typical life span of rubber shingles, until curling or discoloring begins, can be 20 years and occur in as few as 5 years (or less). There is no evidence that they last 50 years (without asbestos) like the warranty says. At least not yet.
Aesthetics – Our synthetic Aledora slate and Classic slate roofing is indistinguishable from natural slate – yet it has an even more refined appearance and is significantly easier to install.
Disagree. A homeowner, who doesn’t understand roofing material, most likely won’t know the difference either way which would make the word “indistinguishable” correct to them. To anyone who knows slate, they can see the rubberized texture is cheesy when compared to slate. A shiny piece of rubber that has the potential to discolor from the sun’s rays is not going to stand up to slate when considering beauty. Notice the beauty of a rubber roof.
Durability – It is shatter resistant unlike natural slate roofing that can shatter when walked upon or in cold weather. Bottom bullet of this webpage,
First of all, slate does not alter with a temperature change, unlike synthetic. Synthetic slate marketing is grasping at any negative aspect of slate they can when they even try to compare the two products. Their product curls, cracks, and disintegrates. .Read more on durability on this excellent article found on Black Diamond Slate. Additionally, a piece of rubber will last for a long time and creates a huge plastic trash heap in the Pacific ocean. Reference article.
Misinformation – “You emulate the natural material, but get performance and longer life over the natural product,” says Charlotte, N.C.-based custom builder, who used ********** roofing on one high-profile project. “You’re saving on potential callbacks.” Nitpicking from 2009
Wrong. This is the type of incorrect info that needs to stop. Whoever is telling the builder this information should be called out. This is incredibly inaccurate and completely false because there is 0 evidence that this type of material holds up for over 100 years. Field testing for this material hasn’t even been around that long. It’s time natural slate fights back.
Testimonials From the Slate Roofer’s Contractor Association
- Our general observations revealed some discolored or faded products. Others curled without cracking but opened enough to allow water into buildings. In general, most fiber-cement materials quickly became unfit for roofing or became so unattractive owners were unhappy with the appearance.
- The relentless marketing by the manufacturers, with claims of 50-75 year lifespans, less weight, colors and designer patterns, and ease of installation coupled with the consumers lack of understanding of natural slate roofs for the most part has left us as traditional roofers little choice but to install these or starve.
- Many of the fake “slate” manufacturers have gone out of business, but new ones keep popping up (synthetic product is deliberately cycled every 15 years to avoid liability). It doesn’t make sense to me to go with an untested product when one that is tried and proven and about the same cost is available.
Read more testimonials from the Slate Roofing Contractors Association website:
Fake Slates
Final Thoughts
The slate industry is being out marketed by synthetic slate manufacturers who have deep pockets and are backed by the giants of the industry. Homeowners are getting an inferior product that is being marketed in a superior fashion. It’s a sad state of affairs that this type of material is being marketed as slate because it is far from the truth. There is no substitute for slate. It’s time tested, eco-friendly, fire-resistant, and beautiful. Rubber shingles are creating a huge dumpster in our ocean because they cannot be destroyed, and this goes along with their dubious nature of the product.
Don’t fake it. Slate it.
Warranty Details
If you want further evidence about the suspect nature of synthetic slate, read what the manufacturer has to say about the warranty. I promise you, no reputable slate installer, with many years of installation experience, has to lose sleep at night wondering if the product will hold up. Remember that.
This is the “Lifetime Limited Warranty” The company has only been around for 19 years. That’s 19 years of their product in the field. Think about comparing this to natural slate which as been field tested for hundreds of years.
Warranty – Only during the first ten (10) years after installation of the Products, … (i) provide replacement Products and Installation Costs to either repair the affected portions of the roof or replace the entire roof as set forth below, or (ii) refund the original purchase price that the Owner paid for the Products. 10 years is not a lifetime.
Wind Warranty – Manufacturer shall have no liability under this Lifetime Limited Warranty for Product damage resulting from or any way related to exposure to winds (i) in excess of ninety (90) mph; (ii) occurring after the first ten (10) years following application; or (iii) any time after the Products have been exposed to winds in excess of ninety (90) mph. You can’t expect our roof to hold up over 10 years!
Color Warranty – All material will weather when exposed to air pollution, acid rain, ultra violet light, weather extremes, and other elements found in the outdoors. The severity of any weathering depends on the geographical location of the building, the cleanliness of the air in the area, and many other influences over which Manufacturer has no control. This Lifetime Limited Warranty will only cover fading in excess of four (4) Hunter units beyond what would be expected in the area in which the Products are installed. Let’s bring out the magnifying glass. That’s definitely 3 Hunter units. Sorry about that.
Tom,
Great stuff as always!
My favorite installation details are from Majestic Slate: Polymeric Slate Tile Roof System.
Checkout:
Temperature Section Page 1
– You can’t store or install these plastic roof shingles in temperatures below 45 degrees!
Bending Section Page 2
– “4. A critical step is BENDING. Every tile that is installed must
be bent in a downward arch before applying it to the roof deck.”
This is hilarious!
Can you tell me of any problems you’ve h ad with the EcoStar Majestic Slate? Mine began having curling and leaking issues on year 9 and EcoStar is telling me that it is not a defect but that it was installed improperly.
Use god-honoring materials, and select a roofer that believes they will burn in hell for eternity if they ever make a mistake. This is the only way to get a permanent roof.
How do you feel about the metal slate, like what is carried by Certainteed? Matterhorn slate?
Matterhorn is another poorly designed roof system. The metal panels in theory may last but like all prefinished metal roofs the flashing details are very tricky to detail. Check out the manufacturers flashing detail drawings, they only exist for basic items and show generic renderings. By the time you flash everything properly (stainless steel or galvanized and soldered) you could install a proven, traditional roof with a far better track record.
Ecostar llc.com has been in business almost 30 years, with installation that look great. Steer clear of companies that have not been operating under the same name for a long time. Article is correct about some newer companies that sell their business and don’t honor warranties. Also, when companies come up with a low priced, smaller, inexpensive version or one that lacks Head Lap.
Can solar panels be installed on a vinyl slate roof?
Great and informative post!
What are your thoughts on the new solar shingles Elon Musk is manufacturing? Another synthetic material that has a short test cycle, but clearly has some benefits for the homeowner.
The material you choose for roofing is paramount. Much like electrical work, the warranty and liability is a huge risk for the installer. As you pointed out, not sure why any roofer would choose a rather untested material and put their name and livelihood behind the work.
I’ve been doing a little research on the Tesla slates- while there’s no denying the company produces some brilliant products, they are not a roofing manufacturer. This is particularly disconcerting to me. I am a traditional roofer with a deep appreciation for natural, time tested products, but I also believe that there is a large market for all synthetic products- from asphalt to plastic and everything in between. The shame is when owners are taken advantage of with trick marketing.
From what I have read, the complete Tesla system, once installed, could cost upwards of $40/sq ft- 4 times the cost of a good quality natural slate roof. This is for a relatively untested product installed by a solar company… not roofers. Do your homework and inform your customers.
Exactly. Not to mention, anyone that is willing to spend $40 per square foot on roofing shingles probably doesn’t need to save $$ on their light bill.
Hilarious. Apparently this didn’t work out so well for Musk. https://electrek.co/2020/06/11/tesla-cancelling-solar-roof-orders-after-years-deposits/
We must always consider the embodied energy of a product, and the energy it demands thru it’s service life. In the case of synthetic slate, it has a similar embodied energy to natural slate without providing nearly the same service life. I would consider it a pass, since we already have vetted, domestic slate which is known to perform when installed right.
About 27 years ago, we were contracted to put a shingle roof on a landmark church in Greenwich Village.
I asked the preservation consultant “ Why are you specifying a 3 tab
shingle instead of an architectural shingle?
His reply was “ The #1 rule in restoration is: never use a product that imitates another product. There is something inherently dishonest in trying to fool people into thinking something is not what it appears.
The church is stating that a shingle roof is what they can afford.
An architectural shingle mimics a wood shingle roof.”
When I look at EIFS (synthetic stucco) it seems like a reflection of the dishonesty so pervasive in our culture.
Landmark Slate & Copper Works
Tom,
Great article. I hope the word gets out on this, it is an article that is long overdue.
I looked up words related to “synthetic” in the thesaurus and it included: artificial, fake, imitation, faux, substitute, so-called, man-made, phony, pretend. (Antonyms: natural.)
All I can say on imitation products is BUYER BEWARE!
Tom,
Well done, we see so many colleges and government buildings being taken advantage of by the imitation slate products.
A local well known college, CNU (Christopher Newport University) has went through two well known imitation slate failures in the past 15 years.
Our local Newport News Police Department, had to replace an imitation slate roof after less than 5 yrs.
And the imitation slate roof on Newport News Library on Main Street is failing. This is the funniest example since it’s right next to Hilton Village, who just celebrated 100 years (all their roofs are original Vermont Semi-weathering Gray/Green slate)
https://en.wikipedia.org/wiki/Hilton_Village
Common sense is not very common, when Yorktown, VA re-roofed their courthouse, I suggested they go with real slate in a light weight application since they were trying to keep the roof weight under 600lbs, but they chose to go with an imitation slate, even though they were already having problem on several of the buildings they had re-roofed with the same product in the last ten years??? I asked why would you do this if it’s already failing on the other buildings, he told me York County taxpayers are wealthy so there is plenty of money to re-roof again in a few years, wow!!
Having been raised in Connecticut I have a real appreciation of real slate roofs on beautiful old colonials. But now I live in the east bay of San Francisco. My beach house overlooks the San Andreas Fault, an my main residence sits squarely on the Hayward fault. Heavy roof shingles are something those of us living on the Ring of Fire avoid at all costs.
So, bottom line, if I lived in New England I would opt for a genuine slate roof any day. But living here in California I’m glad of the option of synthetic slate.
I read your post regarding your use of synthetic slate in California. I am in the Philippines and share the same type of weather conditions as you. I am contemplating the use of synthetic roofing here and would like to hear more of your experiences and manufacturer used. Thank you. Email: [email protected]
I am the owner of the Asbestos One Company, We are located in Columbus Ohio. We install slate roofs and we are the only company in the world to refurbish asbestos roofs. Slate roofing is so easy to install correctly and I am talking about real slate. but I almost bought into having a synthetic so called slate roof on my building, only because of weight. Over the years I have seen it installed on plenty of home and businesses and everyone of them failed in one way or another. Over the last 41 years have seen people try anything just to make a profit, that is what our country has become. the closest man has ever came to a slate roof was when they made an asbestos roof tile and roofers over the years have called it an asbestos slate and the is no such thing. There is one thing that should be called slate and that is a slate.
I work with slate and have seen many fake slate products. Everyone I have seen has had nothing but problems. You just can’t FAKE slate.
Wow, hadn’t a clue about this! We were actually getting ready and looking at different slate roofing systems, but this seems like a red flag to me that maybe I should try something else. I’d hate to pay all that money to have fake slate go on my roof!
Paul, you can do no better than north country unfading black. Top shelf.
Fantastic article Tom. We are a national roofing contractor who has installed many beautiful natural slate projects for our clients. “Real is the deal” Tom. Thank you for your expertise.
Would love to have a real slate roof but my home is not framed for it.
Great article, thank you. I have a slate roof on my home in Norfolk VA. It’s already 90-years old and has no indication of wearing out in my remaining lifetime! I do need to replace the asphalt roof on my addition and garage and was thinking of synthetic slate to match the house. But now I’m wiser, thank you, and will either go with slate, or match the house color with asphalt. Much appreciated, both the article, and the comments from readers.
We just built a new detached garage. Our house was built in 1928 and has its original slate roof. We went with synthetic. Unfortunately, I listened to the contractor and my husband. The synthetic slate looks so flat compared to our home’s roof, even though the color matches well. I’m so sorry we went with synthetic.
I have an Amcraft /Synthetic roof “Slate Dismensions” roof on my southern home in hot unshaded temps. It is now 15 years old with no problems although I’m noticing some minor curling. I remember researching the choices and Amcraft had a good reputation at the time…lAnyone with any real experience with them? Thx
But a roof has to be made to hold the weight of slate, synthetic can be put on any roof with the right pitch. It gives opportunity to houses who want a slate look but can’t put slate on
The only “synthetic slate roofs systems” that should be used and installed are boral or divinchi which now are merging into the same company their products are high grade synthetic and actually do last. No curling, no discoloration. These two complies have been around for a long time and are 100% better then installing a tradition slate roof. Traditional slate is old news. Products like these are beautiful and mimic the slate to a T. Plus the cost for traditional slate installation is very high in price. BORAL/DAVINCHI FOR THE WIN. If your a real roofer you know how to install them correctly, so they will last literally for ever.
Davinchi has been around a while but sold many times. Boral no longer owns them and your post was 5 months ago. You are right to go with a product that has been in the market.
I hate to rain on anyone’s parade, but here is the situation: Slate, like other rock materials, is primarily silicon oxides—inorganic. These materials are resistant to ultraviolet light. Rubber- and plastic-based materials are made of carbon, hydrogen, and oxygen—they are organic.
In your body, bones are inorganic, being mostly calcium; muscles, cartilage, and fingernails, are all organic. When a body dies, the organic parts are gone in a few months—the bones take years to disappear.
It should be no surprise, then, that slate rooves last much longer than rubber/plastic rooves. Still not convinced? Then ask a materials engineer. You will receive much the same answer as mine.
The original Slate Roof that we have came with the house built in 1952 after about 70 years, some are showing that they are about to fall off. We intend to replace it with Galvalume, but it is so beautiful we hate to see them pounded, hammered removed and thrown away. It is very hard to find someone in our area in Havertown, PA to find one who know Slate Roofing Repair. (stone). Can someone refer us to one, please?