How much does a slate roof cost?
How much does a slate roof cost?
$10 – $30 cost per square foot installed
$22,000 – $70,000 average total installation cost
Slate roof cost
A slate roof costs $10 to $30 per square foot installed or $22,000 to $70,000 on average, depending on the slate type, roof size, and condition. Natural slate roof tiles cost $600 to $1,600 per square for materials alone. Synthetic roofing slate costs $9 to $12 per square foot installed.
| Roof size (square feet) | Average total installation cost |
|---|---|
| 1,000 | $10,000 – $30,000 |
| 1,200 | $12,000 – $36,000 |
| 1,500 | $15,000 – $45,000 |
| 1,700 | $17,000 – $51,000 |
| 2,000 | $20,000 – $60,000 |
| 2,500 | $25,000 – $75,000 |
| 3,000 | $30,000 – $90,000 |
| 3,500 | $35,000 – $105,000 |
Average cost of new slate roof
The following table shows the average cost of a new slate roof:
| National average cost | $1,400 |
| Minimum cost | $300 |
| Maximum cost | $4,000 |
| Average range | $500 to $2,100 |
Slate roof cost per square foot
A slate roof costs $10 to $30 per square foot installed for natural or $9 to $12 per square foot for synthetic, depending on location, strength, and roof size and condition. Hard slate is the most fire and weather resistant. Soft slate is less durable but still outlasts most roof types.
| Type | Installed cost per square foot | Lifespan (years) |
|---|---|---|
| Synthetic slate | $9 – $12 | 30 – 50 |
| Soft slate | $10 – $20 | 50 – 125 |
| Hard slate | $20 – $30 | 75 – 200 |
Slate colors include naturally occurring grays, blacks, blues, greens, purples, and reds.
Most colored slate is hard slate, while most black slate is soft slate.
Roofing slate is either unfading, weathering, or semi-weathering, indicating the expected color change over time.
Slate roof shingles cost per square
Slate roof shingles cost $1,000 to $3,000+ per square installed, depending on the roof size, slate strength and thickness, location, and existing roof type and condition. In comparison, installing faux slate costs $300 to $1,900 per square on average, depending on the material.
| Type | Average installed cost per square* |
|---|---|
| Natural slate | $1,000 – $3,000 |
| Faux slate | $300 – $1,900 |
*One square equals 100 square feet.
Slate roof tiles prices
Slate roof tile prices are $6 to $16 per square foot on average for natural slate, excluding installation. Faux slate tiles cost $1 to $11 per square foot, depending on the material. Faux slate tiles may be asphalt, concrete, clay, metal, or synthetic.
| Type | Materials price per square foot |
|---|---|
| Natural slate | $6 – $16 |
| Faux slate | $1 – $11 |
Synthetic slate roofing cost
Synthetic slate roofing costs $9 to $12 per square foot, including installation. Synthetic or composite slate is a plastic and rubber mixture molded to look like natural slate tile. The specific material blend depends on the brand. Synthetic slate weighs less but has a shorter life than natural slate.
Several other roofing materials are available to create a faux slate roof:
Asphalt shingles cost $3 to $5 per square foot installed.
Metal roof shingles cost $6 to $14 per square foot installed.
Concrete roof tiles cost $7 to $19 per square foot installed.
Clay roof tiles cost $8 to $25 per square foot installed.
Slate roof replacement cost factors
| Factor | Cost per square foot |
|---|---|
| Remove old slate roof | $2– $5 |
| New slate roof tiles & fasteners | $6 – $16 |
| New roof decking | $2 – $5 |
| New underlayment material | $0.10 – $0.35 |
| Installation labor to reslate | $4 – $14 |
Factors affecting slate roof replacement include:
Roof size, slope, & pitch – Larger roofs require more materials and labor but typically cost less per square foot. Labor costs increase for steep roofs with pitches over 6:12.
Roof complexity – Roofs with many corners, valleys, skylights, and penetrations require more labor and materials.
Installation method – Steep-sloped roofs typically require batten installation, which costs more than installing tiles directly to the roof deck.
Climate – Cold, wet regions may require an ice and water shield, costing $2 to $5 per square foot installed on average.
Slate hardness – Hard slate costs 50% to 100% more than soft slate but is more durable and longer-lasting.
Slate thickness – The thicker the slate, the heavier and more complicated the installation, which increases labor costs.
Slate color – Unfading slate costs up to 25% more than weathering and semi-weathering colors.
Slate grade – The American Society for Testing and Materials (ASTM) grades slate as S1, S2, or S3. S1 graded slate costs the most, lasts the longest, and is the most common slate on US homes.
Old roof removal – Removing and disposing of an old roof costs $2 to $5 per square foot for old slate or $1 to $3 per square foot if removing old asphalt shingle or tile.
DIY roof removal – Dumpster rental costs $280 to $500 per week.
Underlayment – Roof underlayment costs $0.10 to $0.90 per square foot for synthetic or rubber underlayment, excluding labor.
Structural Reinforcement – Hiring a structural engineer costs $100 to $220 per hour to determine if the roof needs additional support.
Rafter replacement – Replacing roof rafters costs $5 to $14 per square foot, depending on the material weight and roof condition
Repairs – Slate roof repairs cost $500 to $2,100 on average. Purchase an extra square for future repairs when installing a new slate roof. Each lot of slate is different and difficult to match.
Pipe boots & ventilation – Installing a roof vent costs $200 to $700.
Soffits & fascia – Replacing soffits and fascia costs $900 to $6,800.
Permit fees – A roofing permit costs $150 to $500. Contractors often include permit fees in the roof replacement estimate.
Inspection fees – A roof inspection costs $100 to $400.
Labor cost to install a slate roof
Installing a slate roof costs $4 to $14 per square foot for labor alone. Slate roof contractors charge $50 to $100 per hour on average and installation takes 6 to 7 days for an average home. Slate roofs installation is labor-intensive as the tiles are heavy and fragile.
Additional material costs to install a slate roof
Additional materials to install a slate roof cost $2 to $4 per square foot on average. High-quality materials are best to ensure they match slate tile's longevity.
Additional installation materials include:
Nails and flashing – Copper is the most common and recommended material because of its corrosion resistance and long lifespan. Slate roofs typically need at least two nails per tile.
Sheathing – Replacing the roof sheathing costs $2 to $5 per square foot on average. Slate roof decking must be at least 1" lumber or 5/8" plywood.
Water shield / ice dam barrier – Cold, wet regions may require an ice and water shield or bituminous membrane on the eaves, costing $2 to $5 per square foot installed on average. Some roofers recommend installing the barrier on the entire roof.
Snow guards – Snow guards cost $5 to $30+per guard and keep the snow from falling off the roof in large masses.
Slate roof types
Slate roofs may be installed using a variety of techniques, including:
Standard – Standard or uniform slate roofs contain one standard size tile laid horizontally and uniformly, with alternating vertical joints.
Random width – Random width roofs install like standard slate roofs and have the same length tiles, but different tile widths as the name suggests.
Graduated length or thickness – Graduated slate roofs contain tiles of varying lengths and thicknesses, with longer or thicker tiles at the eaves. This graduated method stems from earlier days when slate was not readily available in specified dimensions and thicknesses.
Patterned – Patterned slate roofs use different colored or shaped slate tiles to create visual designs within a standard slate roof.
Multicolored – Multicolored or blended roofs contain 2 to 4+ slate color varieties. Most blended roofs use random width tile installation.
Textural – Textural slate roofs mix thicker and rougher-textured tiles throughout the roof surface.
Hang-down / staggered butt – Slaters lay the tile down to create an appearance of different length tiles, where some tiles "hang-down" further than others instead of all tiles butting in straight horizontal lines.
Pros and cons of slate roofing
Slate roofing is expensive up front but outlasts most other roof materials. Slate's density helps regulate temperature and reduce energy costs. Still, its weight – 8 to 10 lbs per square foot – may not be suitable for every home.
| Pros | Cons |
|---|---|
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Slate tiles vs. asphalt shingles cost
Slate tiles cost $10 to $30+ per square foot installed, while an asphalt shingle roof costs $3 to $5 per square foot. An asphalt shingle roof is cheaper and easier to install than slate but needs replacing after 15 to 30 years. In contrast, a well-maintained slate roof lasts over 100 years.
What is a slate roof?
A slate roof is made from natural slate tiles nailed individually with copper or stainless-steel nails. Slate roof installation requires a trained "slater" to ensure proper headlap for a roof's slope. Headlap—when two tile courses overlap the top or head of the tile—is crucial to prevent water infiltration.
Natural slate is a premium, heavy, and long-lasting material made of fine-grained, metamorphic rock.
Standard slate tiles are 1/4" to 5/16" thick and range in size from 6" x 12" to 12" x 24".
What is synthetic slate made of?
Synthetic slate is made of composite plastic polymers or rubber. The specific material blend depends on the manufacturer.
How long does a slate roof last?
A slate roof lasts 50 to 200+ years, depending on the type and location. Natural soft slate lasts 50 to 125 years, while natural hard slate lasts 75 to 200 years on average. Many roofers call natural slate a "forever" roofing material because a well-maintained slate roof lasts several generations.
How much are old roof slates worth?
Old roof slates' worth depends on the following factors:
Slate type and color
Exact tile size, shape, and thickness
Approximate age and condition
Quantity
Location
Storage method – Store slate roof tiles on their edge on boards. Stacking slate tiles like plates risks breakage due to the weight.
Companies that buy old slates for resale typically require 500 pieces minimum, unless the slate type is rare or precious.
Does a slate roof add value?
A slate roof adds value because it is a premium, long-lasting material. A well-maintained slate roof should not need replacing for a century or more, making it a key selling point and justification for a higher asking price.
Does moss grow on slate roofs?
Yes, moss grows on slate roofs. Moss growth does not harm slate tile, but it prevents the roof from drying completely and may damage the underlying roof sheathing. Remove moss at the first signs of growth and trim surrounding trees to reduce shade and falling debris, preventing more serious issues.
Installing zinc or copper strips along the roof ridge helps prevent or reduce moss growth. Rainwater mixes with moss-inhibiting particles as it hits the strip before running down the roof.
Getting estimates from slate roofers
Before hiring a roofing contractor, be sure to:
Have a structural engineer inspect and determine if the roof needs reinforcement before tiling.
Know your approximate roof square footage so you can confirm the estimate details.
Get at least three estimates to compare.
Hire only licensed roofing contractors specializing in slate roof installation.
Look for trained members of the Slate Roof Contractors Association (SRCA), the National Slate Association (NSA), the National Roofing Contractors Association (NRCA), and the Tile Roofing Industry Alliance (TRI).
Ask for references or a portfolio of past slate roof projects going back at least five years to see how their work holds up.
Ask about the accessory type and quality they intend to use. High-quality accessories are ideal for slate's long lifespan.
Browse their reviews on HomeGuide and Google.
Select companies that are insured and bonded.
Avoid selecting the lowest quote as quality may suffer.
Get a detailed contract and warranty in writing before the work begins.
Never pay in full before the project starts. Use a payment plan instead for work completed.
Questions to ask roofers
Are you licensed, bonded, and insured?
What experience do you have with slate roof installation?
What slate tile do you recommend for my roof, and why?
Do you have a portfolio of your previous jobs?
Will you use subcontractors?
How long will the project take?
Will you install new flashings?
What type and quality of accessories will you use?
How will the crew leave the site at the end of each day?
How will you protect my yard and driveway during the installation?
What type of underlayment do you use, and how many layers do you install?
Is underlayment included in the estimate?
How long should the roof last?
Is there a warranty, and if so, what does it include?
What is and is not included in the estimate?
What additional costs should I expect?
Do you need a permit to install the roof?