Contact Us

Frequently Asked Questions

What minimum roof pitch is required in order to utilize slate?

With special consideration for slate size, headlap and underlayment – natural roofing slate can be applied to roofs with a slope of four inches per foot.

(back to top)

What roof decking is required for the application of slate?

One inch board sheathing or 3/4″ APA plywood provides a suitable deck material for the installation of natural slate. This material provides minimum deflection during nailing, supports the weight of the slate between rafters and provides adequate resistance to nail pull out.

(back to top)

What weights should be taken into account when considering natural slate?

The weight of nominal 3/16″ slate is 7 – 8 lbs. per square foot and nominal 1/4″ is 9 – 10 lbs. It is worth noting that the common practice of applying 3 layers of asphalt shingles, before tearing off, creates a combined total weight of 7+ lbs. As with the application of any roofing material, dead load weights for natural roofing slate should be taken into consideration at the design stage or prior to re-roofing.

(back to top)

What climatic restrictions apply to the use of natural slate?

Good quality natural roofing slate has been used under the harshest climatic conditions in the world and has proven performance dating back a thousand years. Poor quality roofing slate yields a limited life expectancy under moderate conditions and therefor its use should be restricted to milder climates with very careful evaluation of precipitation and freeze thaw cycles.

(back to top)

Can you suggest a competent slate roofing contractor who can supply the slate and install my roof?

We maintain a database of qualified North American roofing contractors who have the necessary skills and experience to install your roof. With some basic information regarding your roofing requirements, we can recommend the contractors that are most capable and interested in your type of project.

(back to top)

How long can I expect a slate roof to last?

The life expectancy of a slate roof will depend on climatic conditions, roof pitch and slate quality. Climatic conditions and roof pitch are variable, however, ASTM International’s C406 Standard Specification for Roofing Slate establishes expected service life for grades of slate as S1 over 75 years, S2 40-75 years and S3 20-40 years..

(back to top)

Do you have a question that needs to be answered? Simply fill out our Mail Reply Form, and one of our representatives will contact you with the answer.

Mail Reply Form
  • This field is for validation purposes and should be left unchanged.