Slate
From MaterialProject.org, the free architectural material catalog
Contents |
Material analysis
MasterFormat 09 60 00
Traditional uses
- Floors
- Roofing
- Landscaping
- Paving
Emerging uses / trends
- Wall cladding.
- Residential kitchen & bath applications; floor, countertop, and backsplash.
- Can be used for interior and exterior applications.
Finish and aesthetic qualities
- Surface finish options include natural cleft, honed, calibrated, acrylic, flamed and polished.
- Typically calibrated on the back side to a flat, even surface for ease in installation.
- Various textures and colors.
- Over 60 naturally occurring colors, from black and deep gray to greens and reddish browns; coloring can be flat and highly uniform or show marked variegation.
- Naturally non-slip surface can be rubbed plain or finished with clear varnish.
- Though it is not necessary, a finish or sealer is recommended for wet locations that protects the slate tile from cracking, peeling and staining.
- Sealers can give the slate a matte or glossy finish.
- Aesthetically creates color, pattern, texture
- Composition: Muscovite, chlorite, kaolinite, micas, quartz and other accessory minerals (wide variation in composition).
Surface forms / shapes
- Tiles and slabs. The composition of shale and clay and the method by which it is quarried alters the surface texture of slate.
- Slate tile is available in a plethora of shapes such as square, rectangular, triangular, irregular, or custom made shapes.
Cost analysis
- Price / SqFt Varies:
- Slab (installed): $20-$40;
- Tile (material only): $3-$6.
Material properties
Primary structural use
- Applied
Material performance
- Slate is a metamorphic rock which is impermeable, hard, close in texture, quick drying,
- Frost resistant
- Fine grained
- Fissile; it splits easily into thin layers.
- Brittle; needs to be handled carefully
- Due to the wide ranges of slate, this stone has wide ranges of weathering.
- Hardness: Soft - hard; Slate can be as hard and dense as granite
- Absorption: Low - medium; oil, water other liquids
- Cleft planes provide permeability for water penetration resulting in splitting and flaking.
- Slates that have a high kaolinite content (a clay) display accelerated rate of deterioration in wet environments
- Tendencies: Absorbs oils and liquids...
- Softer/medium varieties scratches easily.
Dimensional and opening restriction
- Slate slabs & tile can be custom cut to size.
- Standard flooring & wall tile sizes include:
- 8”x 8”
- 12"x 12"
- 16"x 16"
- 24”x 24”
- Tile thickness runs from 1/4" to 1".
- Typical tiles for roofs are 12” – 24” in length.
Acoustic property
- Ideal for acoustical insulation and impact noise resistance.
Manufacturing process and assembly
- Slate is formed from clays, shales, and volcanic ash and is composed of quartz, sericite, chlorite, graphite, and titanium and iron oxides.
- Quarried
- Composition: Muscovite, chlorite, kaolinite, micas, quartz and other accessory minerals (wide variation in composition).
- Special Installation issues:
- Abut to adjacent tile.
- Recommended grout width, 3/16”.
- special consideration:
- When choosing slate as a countertop, choose a tile with minimal cleft or a honed finish, which will minimize uneven surfaces.
Environment and Life Safety
Environmental impact
- Plentiful, but not renewable.
- Slate stone is chemically a multi-mineral rock made of an aggregate of minerals and colloidal substances. Essentially mineral composition includes members of Mica group commonly sericite & muscovite, Clay group commonly paragonite, chlorite & kaonilite. The accessory minerals are oxides, calcites & minor amounts of quartz and feldspar along with subordinate amounts of ferro-magnesium minerals. It is resistant to acids and staining.
- Greatest environmental cost is in transportation, as it often required far from where it naturally occurs.
Flammability rating
- Non-Flammable
Coefficient of friction
- dry 0.86, wet 0.62 (will vary depending on finish and manufacturer).
References
Notes
- Jenkins, Joseph. The Slate Roof Bible: Understanding, Installing and Restoring the World's Finest Roof. Pennsylvania: Jenkins Publishing, 2003.
- Bowers, Helen. Interior Materials and Surfaces: The Complete Guide. New York: Firefly Publishing, 2005.
Student contributions
- Elisabeth Grace, Fall 2005
- Michelle Aberbach, Spring 08
- Kathleen Mannix, Spring 2009
- Klaudia White, Spring 2010
- Amy Doherty, Spring 2010
See also
Similar materials
Building references
- Boston Common (landscaping), Arlington Street Boston, 02116
- Harvard University (slate roof) Massachusetts Ave., Cambridge, MA.
