Tips for Replacing a Slate Roof With Asphalt Shingles

What is a Pitched Roof?

When it comes time to replace your slate roof, asphalt shingles are a likely contender. What if there was a better option? Let’s take a look...

What Is A Slate Roof?

What Is A Slate Roof?

A slate roof is a roof that uses slate shingles for protection against the elements. Slate in its natural form is a metamorphic rock that, according to, is composed of parallel mineral grain alignments that allow the rock to break along its planes of foliation, creating thin sheets that can be used for a variety of applications and products. These sheets don’t absorb much moisture and can handle freezing water and variable temperatures.

In addition to roofing material, slate has been used for chalkboards — which is where the phrase “clean slate” or “slated for today” originated — paving, gravestones, interior flooring, billiard tables, and much more. It’s even used in turkey calls.

As a roofing material, slate is incredibly durable, and hard slate has been known to last 75-100 years. Soft slate can last between 50 and 90 years.

What Are Asphalt Shingles?

What Are Asphalt Shingles?

Asphalt shingles are available in a variety of options and offer an affordable roofing material that fits with most aesthetics. In the early 1900s, asphalt shingles began to replace natural roofing materials like wood, slate, and clay.

Asphalt roofing comes in the form of two main products. Fiberglass asphalt roofing is manufactured with a thin mat of glass fibers and then coated with slate granules. Organic asphalt roofing is made with a mat of cellular fibers, recycled wood fibers or waste paper, for example, and then saturated with an asphalt coating that contains mineral granules and adhesives for adherence.

According to Popular Mechanics, over 75% of U.S. homes use asphalt roofing due to its affordability, easy installation process, and relatively long-lasting durability.

How Is The Cost Of Roofing Materials Calculated?

How Is The Cost Of Roofing Materials Calculated?

There are a few different numbers to consider when you’re calculating the cost of replacing a slate roof with asphalt shingles:

  • Cost per sq. ft. - This is the cost to cover a 1’x1’ square (a sq. ft.) of roof.

  • Cost per square - A roofing square is equal to 100 square feet of shingles, and one bundle of shingles is about 33.3 square feet on average. One square of shingles is equal to three bundles. So, if shingles cost $2 per sq. ft., a square of shingles would cost $200.

  • Cost for labor - Labor costs depend on who is doing the installation and the complexity of the project.

  • Cost for the entire project - After calculating the cost of materials plus the cost of labor, you’ll have the cost for the entire project.

Pros And Cons Of Replacing Slate Roof With Asphalt Shingles


  • Asphalt shingles are more affordable than a slate roof, costing just $1-$2 per sq. ft. for standard three-tab shingles. Slate shingles cost between $9 and $16 per sq. ft.

  • They are easier to work with. Slate can be brittle and difficult to install, but asphalt shingles can be installed quickly and easily with standard tools.

  • Asphalt shingles are lighter than slate shingles, weighing nearly four times less than slate. For new construction, the roof must be specifically engineered to carry the additional weight of slate. If you’re installing a new roof on existing construction, you may have to make structural modifications to account for the added weight. Asphalt shingles can be installed on the existing structure.

  • They can be walked on, though it can still sustain damage and scuffing if it is already in poor shape. Slate isn’t easy to walk on and can be slippery and dangerous if it’s wet.


  • Asphalt shingles become brittle over time after exposure to the sun, wind, rain, and snow. They can also be ripped from the roof in the event of a storm or hurricane.

  • Prone to algae growth, especially on shaded areas, asphalt shingles require regular cleaning and, if covered in algae, can detract from the overall home aesthetic and lead to a lower sale price if you’re selling your home, not to mention the damage to the actual shingles.

  • They aren’t as environmentally-friendly as other options because they are composed of asphalt, which is a semi-solid form of petroleum that produces greenhouse gas emissions and wastes a substantial amount of energy in the manufacturing process.

Synthetic Slate Shingles: A Better Alternative To Replacing A Slate Roof With Asphalt Shingles

Synthetic Slate Shingles: A Better Alternative

For all of their benefits, asphalt shingles leave much to be desired when it comes to a home’s exterior aesthetic. The beauty of a slate roof is costly and requires extra support to accommodate the weight of slate shingles.

A Better Alternative: Synthetic Slate Shingles.

This environmentally friendly composite roofing material features a natural quarried slate tile look and texture, but without the added weight. Rated for the highest level of impact (Class 4), it can withstand even the strongest storms, including hail that can chip and break natural slate.

Our Brava Old World Slate can be walked on without breakage issues, and it is easy to install. We’re the only place that offers multi-colors that are fully blended to mimic natural slate colors. We are so confident in our product, that we offer an amazing 50-year limited warranty.

When you’re ready to create a stunning roof to complete an old world look, look no further than Brava Roof Tile. Contact us today to discuss our options.