Riverstone

A grey-green phyllite — geologically not a slate, though it is sold and laid as one — from SSQ’s own quarry in San Luis, Argentina. It is prized for consistency and a low water absorption of 0.32%, and it is the material that makes the transport question concrete: getting it to a British roof costs about 3.5 times what Spanish slate costs per kilogramme, and that gap is larger than the difference between most competing roof materials.

Manufacturer page
SSQ Riverstone

Carbon and evidence

Product Evidence

Evidence currently held for the SSQ product record.

SSQ

Recorded Carbon Result

0.4644kgCO₂e/kg

A1–A3 GWP per kg of slate, from a declaration whose unit is one 1223 kg crate — an exact division by the stated crate mass. At the declared 21 slates/m² that is roughly 14.9 kgCO2e per m² of roof, though that m² figure is derived rather than declared. This is an EN 15804+A1 declaration with no GWP split and several modules undeclared, so compare it with the +A2 slates on transport (A4), not on production.

Indicator: GWP-total

Riverstone natural phyllite (BREG EN EPD 000472 (Issue 01))

A1–A3 covers raw-material supply, transport to manufacture and manufacturing. It is product-stage information, not a whole-life result.

Environmental Product Declaration

EPD recorded
Coverage
Specific product
Declared unit
1223 kg one crate of about 800 slates
Programme
BRE Global (BRE Global Scheme Document SD207)
Registration
BREG EN EPD 000472 (Issue 01)
Standard
EN 15804:2012+A1:2013, ISO 14025
Valid until
2028-01-26
Verification
Third-party verified

Quarried at SSQ’s own quarry, Ruta 7 Km 781.5, Juana Koslay, San Luis, Argentina. NOTE: Riverstone is PHYLLITE, not slate — a different metamorphic rock, sold and laid as slate. The declaration covers Riverstone ONLY; SSQ’s Spanish Del Carmen slate, which they import rather than quarry, is not covered by any declaration found and this figure must not be attached to it.

Read the EPDSource: GWP rows of the environmental indicators table

Carbon profile

kgCO2e per 1 kg of slate (declaration declares a 1223 kg crate) · each bar starts at zero · local scale

A1-A3 product

0.464

A4-A5 site*

0.332

B use

0.0165

C end of life

0.00311

D reuse / recycling

not declared

—

adds carbon stores or removes EPD scenario* reuse/recycling potential (D)
* EPD transport and installation scenario, not this project's. Not declared: reuse / recycling. Do not compare bar lengths between materials. Each chart may use a different scale and declared unit.

Reported GWP Modules

Displayed as stored; modules are not added together here.

A1–A3

0.464 kgCO₂e

per 1 kg of slate (declaration declares a 1223 kg crate)

A4*

0.19 kgCO₂e

per 1 kg of slate (declaration declares a 1223 kg crate)

A5*

0.142 kgCO₂e

per 1 kg of slate (declaration declares a 1223 kg crate)

B2

0.0155 kgCO₂e

per 1 kg of slate (declaration declares a 1223 kg crate)

B3

0.00106 kgCO₂e

per 1 kg of slate (declaration declares a 1223 kg crate)

B4

0 kgCO₂e

per 1 kg of slate (declaration declares a 1223 kg crate)

C1

0 kgCO₂e

per 1 kg of slate (declaration declares a 1223 kg crate)

C3

0 kgCO₂e

per 1 kg of slate (declaration declares a 1223 kg crate)

C4

0.00311 kgCO₂e

per 1 kg of slate (declaration declares a 1223 kg crate)

* A4/A5 are EPD scenarios, not project-specific results. Module nomenclature follows BS EN 15978 / EN 15804. Declared values are suitable as inputs to a whole life carbon assessment under the RICS Professional Standard (2nd edition); this panel is not an assessment.

Upfront Carbon (A1–A5)*

0.796 kgCO₂e per 1 kg of slate (declaration declares a 1223 kg crate)

A1–A3 0.464 + A4 0.19 + A5 0.142 · GWP-total, as declared

* Includes the EPD’s A4/A5 scenario assumptions, not project-specific transport or installation. This is the aggregation the proposed Part Z applies upfront limits to.

Sourced Product Claims

  • Delivery declared at about 0.19 kgCO2e per kg — 13,890 km by sea from Argentina plus 200 km by roadThird-party verifiedSource
  • Riverstone is phyllite, not slate — a different metamorphic rock sold and laid as slateThird-party verifiedSource
  • EN 15804+A1 — declares a single GWP figure with no fossil/biogenic/luluc splitThird-party verifiedSource
  • Third-party verified EPD, valid to 2028-01-26Third-party verifiedSource

Evidence Sources

Third-party verified

Comparison Status

This result should be displayed for information only and not ranked against another product.

  • • The EPD is not linked to an evidence source.

Design & Specification Notes

Qualitative notes for early design discussion. Not product-specific EPD evidence, and not a basis for numerical comparison.

A grey-green phyllite — geologically not a slate, though it is sold and laid as one — from SSQ’s own quarry in San Luis, Argentina.

Typical Uses

  • •Roof coverings
  • •Waterproofing layer
  • •Weather protection

Key Performance

High durability in wet exposure and wind uplift.

Typical Service-Life Estimate

100 years

Generic estimate for early design discussion; confirm with the manufacturer.

Specification Actions

  • •Confirm the current EPD covers the selected product, finish and manufacturing route.
  • •Calculate transport distances for primary materials.
  • •Document material reuse or reclaimed content percentages.

Indicative Health & Indoor Air

low Risk
Evidence:Third-party verified

Specification

Range
Riverstone
Finish
Natural phyllite roofing slate, 5.3 mm ± 12%
Thickness
5.3 mm ± 12%
Country of manufacture
Argentina

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