Slate Roofing Tiles in Michigan

Roofing slate comes in a wide variety of standard shingle sizes beginning at 12 inches long and increasing in 2-inch increments to as long as 24 inches. Traditional slate widths range from 6-15 inches. Fun fact: a traditional slate’s width is never smaller than half its length.

Although different thicknesses will naturally produce different weights, the most frequently installed thickness of slate will weigh between 935-1170 lbs per 100 square feet of roof area.

The most common type of underlayment used for waterproofing the roof deck is # 30 asphalt organic felt, although different building codes may require different materials based on local climate and weather conditions. This underlayment is usually purchased in 72’ by 36” rolls, which will cover 216 square feet, or 2.16 roofing squares. It is recommended to purchase an additional 10% of the roof’s square footage to account for trimming and overlapping. You can see more about the underlayment installation process here.

Pros:

No other roofing material lasts as long as slate with a life expectancy of a hundred plus years! This longevity contributes to slate’s environmental qualities when compared to other roofing materials such as asphalt shingles which need to be replaced on average every 20 years.

Slate is available in a wide variety of colors, sizes and thicknesses. Whether it’s a single color, multi-colored, scalloped pattern shape, graduated thickness, or random widths, the design options are endless. Your one-of-a-kind slate roof will boost your home’s value and architectural appeal.

Created by nature over 500 million years ago, natural roofing slate is the most historically reliable roofing material. Slate roof tiles have been used in North America, withstanding the test of time for over 400 years.

Additional advantages to a slate roof are that they require minimal maintenance, are unaffected by freeze/thaw cycles and are non-combustible and fireproof. Natural slate meets Class 3 & 4 hail impact resistance which can provide a reduction in residential insurance premiums with some insurance companies.

North Country Slate offers a 75-year warranty on their slate products.

Cons:

When considering a new slate roof, architects and engineers will have to properly design building structures to withstand the weight of a natural slate shingle. On average, a slate roof weighs 800-1,000 pounds per square (one square equals 100 square feet of roof area). Over the years, alternative lightweight slate systems have been introduced to the market, such as SlateTec, which weighs approximately 6 pounds per square feet. Alternatively, North Country Unfading Black is available in 3/16” thickness, which installed at a standard 3” headlap, will weigh approximately 7 pounds per square foot.

The upfront investment costs of a slate roof can appear to be higher than other roofing products, however, when amortized over its 100-year life expectancy it makes it the least expensive roof you will ever purchase.

Installation costs are based on highly skilled craftsman’s hand-nailing each piece of slate into place to ensure a watertight roof system.

Slate roofs are certainly heavier than petroleum-based roofing products.  Whether you are designing a new home or want to switch your existing roof to natural slate, you should consider hiring a licensed structural engineer to evaluate the roof framing. The weights will vary depending on the thickness of the slate. Standard thickness, 1/4″-3/8″ weighs approximately 900-1,000 pounds per square foot.

Not all natural slate roofing materials are the same.  A North American produced slate from Quebec, Vermont and New York is a hard, durable slate and will provide a service life of 75 + years. Some regions of Pennsylvania that historically produced softer black slate had a service life of 50 + years. ASTM C406 is the Standard Specification for Roofing Slate and classifies roofing slate into three grades. Slate is tested for breaking load minimum (ASTM C 120), Water absorption maximum (ASTM C 121) and Weather resistance maximum (ASTM C 217). Based on laboratory analysis, the slate is then graded; S-1 provides a service life of over 75 years, S-2 a service Life 40-75 years and S-3 service life 20-40 years.  It is historically known that some USA produced S-1 slates have provided well over 100 – 200 years of service life.

Hiring a roofing professional who has experience working with slate roofs will help provide you with the advice and service you need.  It’s important that they minimize walking on the slate as much as possible, as this can potentially cause further damage. Visually inspect flashing details around your roof for deficiencies.  Occasionally, broken slates can occur from time to time which are easy to repair and replace. Keep your downspouts and gutters clean. Remember, gutters move water away from your home. An experienced slate roofer will know the color, size and exposure to properly and efficiently fix any potential leaking areas.

As slate is a natural product, its color is derived from its chemical and mineral composition. Depending on the region, slates are available in several different colors.  In North America, we have an Unfading Black produced in Quebec, Canada.  The Vermont/New York slate valley region is known for its Semi-Weathering Gray/Green, Semi-Weathering Gray, Unfading Red, Unfading Green, Unfading Gray, Semi–Weathering Gray/Black, Unfading and Semi-Weathering Purple and Semi-Weathering Vermont Black slate colors. With this wide variety of colors, it creates an opportunity to create a unique, one-of-a-kind slate roof!  Another consideration when deciding on a color is whether you want an “unfading” or a “semi-weathering” color. Semi-weathering slates have a percentage that will change color to buff, tan and brown when exposed to the elements over time.