SIST EN 15801:2010

Overview

EN 15801:2009 (CEN) defines a standardized laboratory method for determining water absorption by capillarity of porous inorganic materials that constitute or are used in cultural property. The method applies to natural stones (sandstone, limestone, marble) and artificial materials (mortar, plaster, brick), whether untreated, treated or aged, and is intended for use where testing does not compromise the cultural value of the object.

Key Topics and Requirements

• Scope: Measurement of amount and rate at which a specimen absorbs water by capillary action through the test surface.
• Specimens:
  • Regular shapes (cubes, cylinders) with minimum dimensions ≥ 10 mm (height and side/diameter).
  • Series of at least 3 specimens; orientation preserved for anisotropic materials.
  • Pre-conditioning to constant mass (oven drying at (60 ± 2) °C or lower temperature/desiccator for temperature-sensitive materials).
• Test equipment (examples specified):
  • Vessel with flat base and bedding layer (filter paper/foam/cotton).
  • Chronometer (±1 s), ventilated oven, analytical balance (±0.01 g), calliper (±0.1 mm), climatic chamber (23 ± 1 °C).
  • Sandpaper P180 (82 µm) and desiccator.
• Procedure:
  • Place specimen surface on saturated bedding layer; start timing.
  • Periodically weigh specimens after wiping surface; first intervals short (especially first 60 min).
  • End when mass change over 24 h ≤ 1% of absorbed water or after 8 days.
• Calculations and graphs:
  • Water absorbed per unit area Qi = (mi – m0) / A (kg/m²).
  • Plot Qi versus square root of time (ti1/2); capillary water absorption coefficient (AC) is the slope of the linear section (linear regression, at least 5 aligned points).
  • Measure dynamic water front height Hi on lateral surfaces and calculate capillary water penetration coefficient (B) from Hi vs ti1/2.
• Reporting: Full test details must be recorded (reference to EN 15801, laboratory, specimen description and provenance, pre-conditioning, water type, time intervals, Qi and Hi values, graphs, AC and B with correlation coefficients, deviations).

Applications

• Evaluating moisture uptake characteristics of building materials and artifacts for conservation, restoration and preventive care.
• Comparing untreated vs treated surfaces to assess effectiveness of water-repellent or consolidant treatments.
• Guiding conservation strategies for stone, brick, mortar, plaster and other porous inorganic components in monuments, museums and historic structures.

Who uses this standard

• Conservation scientists and laboratories
• Museum conservation departments and preventive conservators
• Heritage building/materials specialists and stone/masonry restorers
• Materials testing laboratories assessing porosity and capillary behaviour

Related Standards

• prEN 15898:2009 (terminology for conservation)
• EN 1936 (natural stone - density and porosity)
• EN 12440 (natural stone denomination)
• EN 12670 (natural stone terminology)

Using EN 15801 allows consistent, comparable measurement of capillary water absorption - a key parameter for diagnosing moisture risks and selecting appropriate conservation treatments for cultural property.