Everything You Need to Know About Slate Roofs

Slate Roof Contractors in Nashville

Many people are unaware of all the different roofing material options on the market because nearly 75% of all roofs are covered with asphalt shingles. The other materials available vary in terms of cost, durability, and aesthetics. The most durable and longest lasting material is slate, which has become increasingly popular.  Slate roofs can last anywhere from 60 to 200 years and require little maintenance.  They are very beautiful and stand out, especially when installed in unique color patterns.

Slate roofing shingles are 100% natural and are quarried directly from the earth. They have a high percentage of mica, which gives off a low level shine when light hits it.

The History of Slate Roofs

Slate roofing has been used in the United States since the 1600s. Building ordinances dating back to the seventeenth century recommended slate or tile roofs because of their fireproof qualities. In the early years, slate was imported from Wales, but in 1785 the first commercial slate quarry was opened in Pennsylvania.

After the Civil War, slate production increased significantly as quarries were opened in several other states, and the United States became a slate exporter with over 200 slate quarries by the early 1900s.

The United States slate roofing industry began to decline around 1915 for a couple of reasons.  It was difficult to find skilled labor to fabricate the slate tiles and to install them.  There was also competition from other materials such as asphalt shingles that were cheaper to produce, transport, and install.

Slate has recently become more popular again due to historic preservation efforts and more education about all of its benefits.

The Pros and Cons of Slate Roofing

Like every other roofing material, slate has its pros and cons:

Pros

Aesthetically Pleasing: Slate roofs are beautiful and draw people in more so than any other roofing material. Slate roofing tiles are available in a wide range of sizes, colors, and thickness, allowing homeowners to choose a really unique look for their home.

Durability: When slate roofs are installed correctly, they should last between 100-150 years, which is a lot longer than the average 20 year lifespan of other types of roofs. Slate is unsusceptible to insects like termites, and it absorbs very little water, which is the main cause of roof problems.

Fire Resistant: Slate tiles are completely fireproof. While this won't completely protect a home from burning, it will prevent fires that could be caused by airborne sparks or embers.

Eco-Friendly:  Roofing waste is a huge portion of the total waste sent to landfills each year, and the majority of that waste is caused by asphalt shingle roofs because of how often they need to be replaced.  Slate is a natural stone that does not have to be manufactured, and typically needs to be replaced every 100-150 years, both of which help minimize its effect on the environment.

Low Maintenance: Slate roofs require very little maintenance.  They are mold, mildew, and fungus resistant. Tiles will need to be replaced if they break since water will be able to penetrate, but other than that, nothing else needs to be done.

Improve Home Values:  When someone is looking to buy a home, the condition of the roof and time frame it will need to be replaced are major decision factors.  Because a slate roof will likely not have to be replaced in a home's lifetime, the value of that property increases.

 Cons

High Cost: The cost of the slate materials and installation fees are significantly higher than other roofing materials, making it difficult for a lot of homeowners to afford. In some cases, slate roofs cost between $1000-2000 more per square foot than asphalt shingles.

Weight: Slate roofing shingles weigh between 800 and 1500 pounds per square foot, which is 4 times heavier than conventional shingles. Many homes are not built to hold that much weight, so there will be an added cost to shoring up the roof in order to support that extra weight.

Difficult to Install: Many roofing contractors do not know anything about slate roofs or how to install them.  Often times, they will still try to install a slate roof anyway, leading to many costly problems.  It is difficult to find contractors who are experienced with slate roofs, and if tiles need to be replaced in the future, you will definitely want to hire someone who knows what they are doing.

Types of Slate Roofs

There are many different methods of slate roof installation, most of which have been developed by local requirements, regional supplies, or the creativity of the roofing contractor.

Standard - comprised of slate tiles that are all the same length and width and cut square.  The tiles are laid in horizontal lines that are uniformly spaced, and alternating vertical joints are aligned.

Patterned - consist of different colors or shapes laid in a design. Some examples include floral or geometric patterns.

Random Width - slate tiles of the same length and thickness but different widths are used in this type of roofing.

Blended - blended roofs mix various colors together to create a multicolor effect. Random width tiles are commonly used, and any amount of colors can be used.

Graduated Length - in the past, many slate quarries did not produce tiles in specific lengths and widths.  The roofing contractors would sort the slate on site and install the tiles with the longest and widest measurements at the eaves, and then install the shortest and narrowest ones towards the top of the roof.

Graduated Thickness - tiles with different thicknesses are placed with the thickest at the eaves, and then with smaller thickness towards the top of the roof.

Textural - tiles of various roughness or texture are mixed in with smoother tiles to create a unique textured look.

How to Care for Slate Roofs

Slate roofs do not need much care, and will last much longer when they receive less foot traffic.  Keep people off the roof as much as possible, but when it is necessary to go up there, be sure soft soled shoes are worn.

We recommend a visual inspection of a slate roof every year to look for cracked, loose, or missing slate tiles.  Replacing any damaged or missing tiles as soon as possible is important.  We also recommend proper tree trimming around the home regularly to ensure branches do not get too close to the roof and damage it.

If you have a slate roof in the Nashville area, the team at Nashville Roofers is available for roof inspections and roof repairs.  If you're interested in a slate roof for your home, we are trained in slate roof installation as well.  Give us a call so we can discuss further.