A test certificate that names a standard but not a sample count is not evidence. BS EN 1926 requires a defined specimen geometry and a stated number of specimens. A certificate reporting a single compressive figure with no specimen count and no coefficient of variation is reporting an anecdote.
Check one: does the certificate identify the batch, and does that batch identifier appear on the crate marks. If the two cannot be reconciled, the certificate belongs to some other stone.
Check two: are dry and saturated compressive values both present. Saturated values typically fall 12 to 18 per cent below dry for a fine limestone. A certificate showing no drop, or a drop beyond 25 per cent, needs an explanation.
Check three: is slip resistance quoted as a pendulum test value with the slider grade stated. A quoted R-value from a ramp test is a different measurement and UK access consultants will not accept the substitution.
Check four: is frost resistance reported with a cycle count and a mass loss figure. A pass with no cycle count is unverifiable. Fifty-six cycles is the meaningful benchmark for UK external work.
Certificates issued against our shipments carry batch identifiers matching the crate stencils, specimen counts for every mechanical test, and both dry and saturated values. Where a UK verification test has been carried out, the verifying laboratory is named on the face of the document.