This standard prescribes the laboratory method for determining the permeability of natural building stones. It outlines the apparatus required, specimen preparation, and the testing procedure for measuring the flow of water under pressure through stone to calculate its permeability coefficient.
Methods of test for determination of permeability of natural building stones
Quick Reference Values
Specimen shapeCylindrical
Typical specimen diameter40 mm to 50 mm
Specimen length to diameter ratio1:1
Test fluidDe-aired distilled water
Key Formulas
K = (Q * L) / (A * H * t) — Coefficient of permeability (Darcy's Law)
Practical Notes
Ensure water used is thoroughly de-aired, as trapped dissolved air can block the micro-pores of the stone and falsely lower the permeability reading.
The sides of the cylindrical test specimen must be perfectly sealed (often using wax or resin) inside the cell to prevent water bypassing along the edges.
Specimens must be fully saturated before commencing the actual permeability measurements to ensure steady-state flow.