How Much Does Slate Flooring Cost to Install in 2025?

This article was updated using automation technology and thoroughly reviewed for accuracy by HomeAdvisor Editor Ryan Noonan.

On average, installing slate flooring costs $10,400 for an 800-square-foot space, with most homeowners spending between  $8,000 and $12,800. Factors like tile type, size, thickness, color, and prep work influence the total price. Hiring a professional ensures a precise installation, resulting in beautiful slate flooring your family can enjoy for years to come.

Slate Flooring Cost Factors

Whether you're installing slate tile inside or outdoors, several factors impact the total project price. Some of the most significant cost factors include the slate size and thickness, color, and substrate.

Size and Thickness

Slate tiles cost between $9 and $40 per square foot, depending on their size and thickness. Larger tiles are more expensive because they're heavier and more challenging to quarry, cut, and transport. They also have a higher risk of breakage, which increases costs. Larger tiles make a bold visual statement, while smaller tiles offer better traction due to more grout lines providing grip.

Additionally, thicker tiles use more material per square foot, naturally costing more. They also cost more to transport per square foot because of their increased weight. Thicker tiles are more durable and are a good choice for flooring in heavily trafficked areas and outside, while thinner tiles are lighter and better for use upstairs.

Color

Standard gray and black slate tiles are typically the least expensive options. Rarer colors like green, red, purple, gold, and blue cost toward the higher end of the $9 to $40 per square foot range due to their scarcity. For an additional $2 to $4 per square foot, you can apply a color-enhancing sealant after installation to enhance the natural hues, giving the slate the appearance of wet stone.

Slate Slabs

Slate slabs are expensive because mining them is more challenging and the slabs are heavier, so they're more costly to transport. Slate slabs are thicker than tile and are extremely durable. They’re generally used outdoors because of their slightly rougher, more organic appearance.

However, their weight makes them unsuitable for use above the ground floor unless you reinforce the floor. Walkways, patios, and outdoor kitchens are all common places to use slate slab flooring. The cost to lay slate slabs outside for any purpose is the same as the cost to build a stone patio from slate slabs, at approximately $15 to $50 per square foot for both materials and labor.

Substrate

Adding and leveling new underlayment costs $3 to $22 per square foot. For slate tile, the substrate must be durable and level, typically made of poured cement or backer board atop the subfloor. A proper underlayment is essential to support the weight of slate and prevent cracks, breaks, or water damage over time.

Outside Slate Tile Cost Factors

When installing outdoor slate flooring, you may encounter additional costs:

• Adding natural stone tile steps costs $1,000–$3,100.

• Regrading a lawn costs $1,100–$3,400.

• Excavating land costs $1,700–$6,800.

• Tree removal costs $200–$2,000.

• Landscaping costs $1,250–$6,050.

Outdoor slate tiles require extra reinforcements, like a veneer underlayer or an existing patio foundation, to ensure durability.

DIY Slate Tile Floor vs. Hiring a Professional

While experienced DIYers might tackle small slate tile projects, hiring a professional ensures a high-quality installation, especially for larger areas, intricate patterns, or spaces requiring precise cuts. A professional has the expertise and tools to deliver a beautiful, long-lasting slate floor.

If you hire a professional, ask about all the specifics when you get a quote. In addition to the cost of installing the tile, you'll want to make sure the estimate includes grouting and sealing the tiles. Most professionals include this in the price, but get the quote in writing to protect yourself from hidden charges. Hire a local tile contractor to ensure your slate flooring is installed correctly and looks its best.

How HomeAdvisor Gets Its Cost Data

No place is more important than your home, which is why HomeAdvisor connects homeowners with local pros to transform their houses into homes they love. To help homeowners prepare for their next project, HomeAdvisor provides readers with accurate cost data and follows strict editorial guidelines. After a project is complete, we survey real customers about the costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects.