FAQ

What are slate roofs?

Essentially a slate roof is a stone roof! Slate roof tiles are made of metamorphic rocks which are derived from sedimentary rock of volcanic ash and clay. Created by the forces of nature over 500 million years ago, slate roofs have provided shelter to homes, churches, courthouses, universities and historic buildings for more than a thousand years. As a natural product, no two pieces of slate are the same. There will be a variation in shade, veining, texture and grain. Being a natural stone they are environmentally friendly and don’t give off volatile organic compounds (VOCs) or other pollutants.
If you’re missing a few slate shingles do I need to replace the entire roof?

The rule of thumb is if 20-30% of the slates are damaged, it’s better to replace the entire roof. If it’s just a few pieces, a skilled slate roofer will be able to match the existing color, size and thickness and with a copper repair hook can slide the new piece back into place.
How much does slate weigh?
SLATE IS AVAILABLE IN SEVERAL THICKNESSES DEPENDING ON THE SUPPLIER. The weight is based on the pounds per square. One roofing square covers 100 square feet. The most common thickness is 1/4” to 3/8”.
- 3/16” (675-700 LBS)
- 3/16” – 1/4” (820 LBS)
- 1/4” (935 LBS)
- 1/4” – 3/8” (1170 LBS)
- 3/8” (1405 LBS)
- 1/2” (1870 LBS)
Where does slate come from?

Roofing slate is actively produced from high quality North American quarries located in Vermont, New York, Virginia and Quebec, Canada
What is the price difference between unfading and semi-weathering slate?

Natural roofing slates are classified based on their weathering characteristics. Please note that a semi-weathering slate is not inferior to an unfading one, the weathering characteristics of a slate has to do with its chemical and mineral composition. The price may vary slightly depending on the color, size and availability. The most expensive roofing slate is an unfading red due to its limited availability and production.
Where to buy slate roof tiles?

If you are reading this then you’ve come to the right place! Buying a slate roof can be one of your most expensive purchases, but also a wise one when you consider how long they last. Keep in mind, not all slates are created equally. Do your research as slate can come in three different grades. Slates should be tested by the quarry or slate supplier to ensure they meet the ASTM testing requirements. An S-1 slate will last over 75 years, a S-2 will provide a service life of 40-75 years and an S-3 will last 20-40 years. Some S-1 slates have lasted well over 100 years! With that said, you may be enticed with foreign slate pricing. Ask the supplier for up to date ASTM test results to ensure you are getting a good quality slate.
What kind of Slate roof underlayment is necessary?

Traditionally, a slate roof will have #30 (thirty-pound) asphalt saturated organic felt unperforated roof underlayment. Required by many building codes, a slate roof’s underlayment serves many purposes and application may vary depending on thicknesses of slate, weather conditions of the area and size of slate. Order an extra 10% of underlayment to account for overlaps and waste. Underlayment is sold by squares similar to roofing slate. A 3’ x 72’ roll will cover 216 square feet which would cover 2.16 squares. You can SEE MORE OF THE SLATE ROOF UNDERLAYMENT PROCESS HERE.
Are slate roofs good?

Natural slate roofing has been used for hundreds of years and can last well beyond 100 years when installed properly using an ASTM S-1 rated roofing slate. Not only are they durable and long lasting, but they are also non-combustible (fireproof), unaffected by freeze/thaw cycles, environmentally safe, and can be made up of an assortment of colors with unfading and weathering characteristics.
How to remove slate roof tiles?

You will need a slate hammer and slate ripper. A slate ripper weighs 3 lbs and is made of carbon steel, including the handle it is 30.5” long. Once you have identified the piece of slate to be removed, slide the ripper under the slate tile. You may need to hit the ripper’s handle to reach the nails to be cut with the hook at the top of the ripper. Once the nails are cut, you will then be able to slide the slate out. Check out 3 TOOLS YOU SHOULD INVEST IN WHEN INSTALLING AND MAINTAINING A SLATE ROOF
How is slate roofing made?

The Glendyne quarry that produces our North Country Unfading Black slate uses diamond wire, which is threaded onto a continuous wire loop that is passed round the area of slate to be extracted. Once the block has been wire sawn it is extracted from the rock face using a hydraulic pecker which is split into more manageable sizes. These blocks which can weigh over 5 tonnes are transported to the mill where they are marked by a trained quarry expert who determines the best potential size to be produced. The marked block then goes through the primary and secondary sawing department which cuts the block into more manageable slabs. The slabs then move onto the splitting department where they are split into approximately eight 1 ½’ thicknesses. The slates are then trimmed to the desired final size and the trimming machine removes the sawn edges and creates the bevelled edges. The final stage, the slate goes thru is grading and packing to ensure high quality controls. YOU CAN SEE MORE ABOUT HOW SLATE ROOFING IS MADE HERE.