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.
North Country roofing shingles, when fixed with non-corroding nails or hooks, can provide a service life in excess of 100 years.
- Requires minimal maintenance
- Durable and long lasting
- Resistant to chemical pollutants and acid rain
- Non-combustible and fireproof
- Unaffected by freeze/thaw cycles
- Environmentally safe
- Resistant to hail and other impact damage
- Performance proven on rooftops
- Delivered from stock
- Available in unfading or weathering colors
- Available in special shapes
- Available in a wide variety of sizes
- ASTM E108-10 Class A (highest) Fire Resistance Rating*
- FM4473 Class 3 or Class 4 Hail Impact Rating**
- ASTM D3161-15 Class F (highest) Wind Resistance Rating***
*As per 2015 International Building Code section 1505.2 and tested by the National Slate Association July 13, 2010.
**As tested by the National Slate Association February 25, 2010.
***As tested by the National Slate Association December 8, 2015.
Fire Resistance of Natural Slate Roofing – UL 790
“Standard Test Methods for Fire Tests of Roof Coverings ”
Natural slate received IBC Class A (highest fire rating available) Fire Resistance Rating when 1/4” thick, North American slate shingles were installed at a 3” headlap over No. 30 felt underlayment on a 1/2″ plywood roof deck.
Click on report – NSA Fire Resistance Of Slate Test Report
Fire resistance of roofing slates: Mechanical, mineralogical and aesthetic changes alongside temperature increase
Victor Cárdenes is geologist with a PhD in roofing slate. Currently a part-time professor at the Oviedo University, Petrology and Geochemistry Department in Oviedo, Spain.
Click on report – NSA Fire resistance of roofing slates temperature increase Report
Complying with Factory Mutual FM 4473, Specification Test
Standards For Impact Resistant Testing Of Rigid Roofing Materials
By Impacting With Freezer Ice Balls.
3/8” thick, S-1 rated, North American produced roofing slate met Class 4 requirements, surviving the impact of 2” ice balls travelling at 76 MPH.
1/4″ thick, S-1 rated, North American produced roofing slate met Class 3 requirements, surviving the impact of 1 3/4″ ice balls travelling at 69 MPH.
Click on report – Hail Test Report
It is important to note that some insurance companies offer a reduction in residential insurance premiums when a Class 3 or Class 4 rating is met.
Impact Resistance of Natural Slate Testing Video
ASTM D3161/D3161M-15: Standard Test Method for Wind Resistance of Steep Slope Roofing Products (Fan-Induced Method)
Testing conducted by PRI Construction Materials Technologies LLC, 1/4’’ thick, S-1 rated, North American produced roofing slate met the requirements of the highest Class F (110 mph) roofing product.
Click on report: ASTM D3161 D3161M-15 Standard Test Method for Wind-Resistance of Steep Slope Roofing Products