Slate Roofing FAQs
Thirty years of supplying natural slate means we get asked the same questions often — and some difficult ones too. These are the answers, in plain language. For deeper technical detail, follow the links at the bottom of the page.
THE BASICS
What is slate?
Slate is a fine-grained, metamorphic rock formed from clay or volcanic ash. Its durability, natural beauty, and ability to be split into thin sheets make it ideal for roofing.
What are the benefits of slate roofing?
Slate offers exceptional longevity (often 100+ years), superior fire resistance (Class A fire rating), weather resistance, and a timeless aesthetic. It can also significantly increase a home's resale value and overall prestige.
How long does a slate roof last?
Properly installed natural slate routinely lasts 100 years or more. Many historic slate roofs are well past that and still performing.
Is slate fire resistant?
Natural slate is non-combustible and Class A fire rated. It will not ignite, melt or warp. This matters in California wildfire zones, where Building Code Chapter 7A requires Class A roof assemblies in Wildland-Urban Interface areas and State Responsibility Areas.
Is slate environmentally friendly?
Yes, slate is a 100% natural material, quarried with minimal processing and boasts an incredibly long lifespan, reducing the need for frequent replacements. Choosing California Slate minimizes environmental impact compared to many other roofing materials.
What colors does slate come in?
California Slate is available in a diverse palette of natural colors from around the world, including a range of grays, blacks, greens, purples, and earthy multi-colors. The specific hues and tones vary depending on the slate's origin and mineral composition.
Will slate fade over time?
Some slates are "unfading," meaning they retain their original color. Other slates may "weather," exhibiting subtle color changes over time, which many find adds to their unique character and charm.
What is a "square"?
In roofing, a "square" is a unit of measurement equivalent to 100 square feet of roof area. This standard unit helps in estimating the amount of roofing material needed for a project.
More detailed answers