When it comes to durable roofing material, nothing can compare to slate. Slate has a very low water absorption index, making it waterproof and resistant to frost damage. It doesn’t burn, corrode, or break due to freezing.
The beauty of slate also never goes out of style. As a roofing material, it can give your home a timeless classic appearance. Given the proper installation and maintenance, a slate roof can last for a century. And because it is built to last a lifetime, slate roofing can be very expensive. But the question still remains: how much does slate roofing cost?
Average Cost of Slate Roof
The estimated slate roof price for a 1,500-square-foot roof – materials and labor included – ranges from $18,000 to $22,000 for a low-grade slate roof. Meanwhile, an upscale slate roof with extras can cost around $26,000 to $40,000.
Slate tile and pattern
A slate roof can either be made from natural or synthetic slate tiles. Natural slate is limited and difficult to obtain, hence it’s more expensive than its synthetic counterpart. Natural slate can cost $4 to $6 per square foot while synthetic tiles are usually sold from $2 to $3 per square foot.
Aside from the roof area, the pattern of the tiles will also determine the number of tiles needed. A highly intricate roof pattern will require more tiles, which can increase the overall slate roofing cost by about 20% to 30%.
Installing a slate roof requires a highly specialized skills and tools. It’s also more tedious and takes more time than other kinds of roof installation. Depending on the area and complexity of the roof design, a professional “slater” may charge around $3 to $6 per square foot.
Slate can weigh up to 900 pounds per square (100 square feet). Support beams are required to bring it up the roof. A scaffolding for a 1,500-square-foot roof can cost an additional $2,000 to $4,000.
Tools and materials
Professional slaters often bring their own tools but you will have to provide their materials. Related supplies like drip edges, weather shield, and basic flashings can add to the total installation cost by about $2 to $3 per square foot.
If you want to avail of the total slate roof package, here’s a list of optional roof enhancements to choose from:
- Heat tape (per clip) – $2
- Gutters (per linear foot) – $3 to $5 (vinyl); $4 to $9 (galvanized)
- Water diverter – $20 to $50
- Ridge vent – $400 to $500
- Solar tube – $500 to $1,000
- Roof sealant – $850 to $1,000
When estimating slate roof price, keep in mind that you’re not only paying for the slate. Here are several factors that also contribute to the installation cost:
Type of slate tile
Slate tiles have varying sizes, thickness, and quality. The thickest and the rare ones with unique colors are more expensive than the normal slate.
Slate is also classified according to its durability and length of life span. The longer it can last, the more expensive it will be. The cheapest slates can last for at least 30 years. Meanwhile, mid-level slate can reach up to 40 years while high-end slate are estimated to last for more than 70 years.
Given the expensive price of slate tiles, its installation should only be handled by a professional. Since slate is more difficult and takes longer to assemble, the labor fee is higher for slate compared to the labor cost of other roof materials. Roofs with steeper slope and complex architecture can also increase labor fees by 20% or more.
A typical slate order within the US is either delivered by a tractor-trailer or a truck. Depending on the number of tiles and location of the supplier, the delivery time and cost for these services vary according to the supplier.
As much as possible, buy slate directly from the quarry to save on delivery cost. It’s because freight charge is a fixed rate based on carload lots. Buying direct is also very cost-effective especially if you’re ordering a huge amount of slate.
Sorting, grading, and wastage rates
Sorting is done to check for any damages in the slate and eliminate broken or scratched tiles. Meanwhile, grading makes sure that each batch of tiles are constructed and appear as similar as possible to each other. These two process are necessary to ensure that only high-quality slate tiles will be used. Unfortunately, it also leads to wastage and increases slate roofing cost.
During delivery, wastage is estimated at 2% to 3% while getting the slates up the roof may cause about 2% wastage. If you factor in sorting and grading, this means that about 6% to 8% of the total tiles are unusable due to damage. Because of this, you will have to order an extra 10% of the total number of tiles to compensate for the wasted tiles. Thus, wastage adds to the overall slate roof price.
Other related materials
Installing a slate roof without any kind of support beam is almost next to impossible due to slate’s heaviness. The most common method used to bring slate to the roof is through a scaffolding. This adds a significant amount to the total installation cost.
Slate roof installation may also take several months to finish. To protect your roof from shedding water and exposure to the elements, a weather shield with a bituminous membrane is used.
A roof is more than just its material. To properly estimate the price of a roof, you will have to look at it as a sum of its parts. Labor, area, design, supplies – these are just some of the things that you need to consider before starting any roof project. A slate roof may discourage some homeowners because of its price but if you want something that lasts for a really long time, then slate is definitely something worth looking into.