CEN/TC 346/WG 3 - Evaluation of methods and products for conservation works

This document specifies a methodology applying poultices for the desalination of porous substrate constituting cultural heritage. The desalination methodology can be applied:
-   to salt-loaded porous inorganic materials affected by salt weathering, and/or
-   to allow conservation treatments incompatible with soluble salt(s) contamination, or
-   to prevent salt damage where contamination is known to be present.
In all cases the desalination aims to decrease the salt content.
Furthermore, this document gives the fundamental requirements for the desalination operation and guidelines for the choice of the most appropriate poultice components according to the characteristics of the substrate and types/quantities of salt(s) present in order to optimize the desalination process.

This document establishes the methodology to measure the quantity of water absorbed by a defined surface of a porous inorganic material used for and constituting cultural property, by contact sponge method.
The method can be used on porous inorganic materials which are untreated or have undergone any treatment or ageing.
The method can be used both in the laboratory and in situ on flat surfaces.
NOTE 1   Treated materials are those which have been subjected to cleaning; to the application of water repellent, consolidating and/or biocidal products; to artificial aging tests, etc.
NOTE 2   The test is not intended to be used on surfaces which are severely deteriorated, where application of the sponge is likely to cause material loss. The operator is expected to ensure good contact with the perimeter of the container. The test is not accurate when applied to rough surfaces.

This document gives the test methodology for evaluation of both harmfulness and effectiveness of a cleaning method as applied to porous inorganic materials. Mural paintings and polychromy are excluded.
Evaluation includes the use of on-site analyses and/or laboratory studies.
The evaluation of the potential harm has a higher priority than the effectiveness in order to prevent overcleaning. It is important that cleaning is always at the minimum level deemed effective and that it respects the original surface and finishes. Overcleaning is a term used to indicate that irreversible damage has been done by the unnecessary removal of materials, which are part of the value of the object.
This document applies to:
a) Part A: all methods of cleaning, which have characteristics of parameterization and reproducibility (see EN 17138).
b) Part B: all new methods that are under development.
This document applies to evaluate the optimum methods for cleaning and the optimization of the parameters of the selected cleaning process.

This document specifies a methodology for the characterization of mortars by using the most appropriate analytical techniques on samples taken from cultural heritage structures and objects.
This document contains guidelines for the selection of methods to determine mineralogical, textural, physical, chemical and mechanical properties of mortars used in cultural heritage structures and objects. This information is used to define mortar typology and to evaluate the mortar condition with respect to its conservation as well as for understanding of the ongoing deterioration processes.

This document provides the guidelines for the choice of the operational cleaning technical specifications in order to optimize the cleaning operation. The fundamental requirements for each specific cleaning method are given as to adapt cleaning works for single specific cases.
The objective of cleaning may consist of removal of any combination of unwanted materials, such as: degraded protective coatings, surface or near-surface materials, which constitute a present or future threat to conservation, materials which prevent legibility of the object or are disfiguring by nature, deposits which are judged to be incompatible to the historical nature of the object.

This document specifies the information contained in the technical data sheet of the product in order to allow a preliminary selection of the most suitable products to use in a specific case of intervention.

This document assesses the long-term susceptibility to light of materials and treatments used in conservation of porous inorganic materials. Examples may include materials which have been treated in the course of conservation (e.g. cleaning, consolidation, water repellents, coatings or biocides) or materials which may exhibit colour changes following exposure (e.g. mortars and small number of stones). The procedure can be used to evaluate the impact and longevity/durability of treatments against untreated materials or unexposed materials.
NOTE 1   Porous inorganic materials are both natural stones (rocks) and artificial stone materials (mortars, stuccoes, bricks, ceramic materials, etc.).
NOTE 2   Treated materials are those on which one of the following treatments has been applied: cleaning, application of water repellent, consolidating materials, coatings or biocides and artificial ageing.

This European standard applies to porous inorganic materials constituting cultural heritage. It provides the fundamental requirements of the laser parameters and guidelines for the choice of the laser operational parameters, in order to optimize the cleaning procedure.

This European Standard describes the terminology for mortars used in the field of cultural heritage.
NOTE   In addition to terms used in the three official CEN languages (English, French and German), this European Standard gives the equivalent terms in Dutch, Italian, Greek, Swedish and Spanish; these are published under the responsibility of the member body/National Committee for NEN, UNI, ELOT, SIS and AENOR and are given for information only. Only the terms and definitions given in the official languages can be considered as CEN terms and definitions.

This European Standard specifies a methodology for the characterization of sound or deteriorated stones by using the most appropriate analytical techniques on samples taken from the object.
This European Standard contains guidelines for the selection of methods to determine mineralogical, textural, physical, chemical and mechanical properties of natural stone used in cultural heritage monuments and objects. This information is used to define rock typology and to evaluate the stone’s condition with respect to its conservation as well as for understanding of deterioration processes of natural stone. Where possible existing standards are referred to and guidance provided where different specimens are required and additional methods used. The methods described are generally destructive, however, non-destructive (NDT) methods are always preferable to methods with a minimum of destruction and those are always preferable to destructive methods.
Methods used for stone analysis can vary depending upon the objectives of the work. All investigation and analysis need be proportional to the significance of the building or artefact being investigated, its condition and the likely level of intervention. This European Standard will be used to determine the kind, extent, and objectives of the examination to be made.

This European Standard provides a methodology for the qualitative and quantitative analysis of anions and cations obtained by dissolution of soluble salts present in either natural stone or other porous inorganic materials constituting cultural heritage and in materials and products used for their restoration. The methodology requires samples to have been taken from the cultural property.
The main ions considered in this standard are:
Cl-, NO2-, NO3-, SO42 -, Na+, K+, NH4+, Ca2+, Mg2+

This European Standard specifies the methodology for laboratory evaluation of the performance of water repellent products on porous inorganic materials.
It is based on the measurement of several parameters which assess the performance of the product using standard test methods before and after ageing.
Acceptable performance within the laboratory does not constitute a blanket endorsement of application in every situation. The particular context of the heritage object, including such factors as material designation, condition, exposure, salt content and problems related to water ingress requires further investigation.

This European Standard specifies a method for the determination of the drying behaviour of porous inorganic materials used for and constituting cultural property. The method may be applied to porous inorganic materials either untreated or subjected to any treatment or ageing.

This European Standard provides a methodology and criteria for sampling cultural property materials for their scientific investigation. It covers, for example, how to characterize the material(s), assess the condition, determine the deterioration causes and/or mechanism(s) and decide on and/or evaluate the conservation treatment(s). Apart from sampling, this document also provides requirements for documentation, and handling of sample(s).
This European Standard does not deal with the decision making process for taking a sample nor how the sample is to be used.

This European Standard specifies a method to measure water absorption of porous inorganic materials used for and constituting cultural property by pipe method.
The method may be used on porous inorganic materials which are untreated or have been subjected to any treatment or ageing.
The method may be used both in the laboratory and in situ due to its non destructive nature.

This European Standard describes a test method to measure the surface colour of porous inorganic materials, and their possible chromatic changes. No reference to the appearance of glossy surfaces is described. The method may be applied to porous inorganic materials either untreated or subjected to any treatment or ageing.
The method is suitable for the measurement of colour coordinates of:
-   representative surfaces of specimens, see 3.11;
-   representative surfaces of objects, indoors or outdoors.

This European Standard specifies a method for determining the water vapour permeability (WVP) of porous inorganic materials used for and constituting cultural property. The method may be applied to porous inorganic materials either untreated or subjected to any treatment or ageing.

This European Standard specifies a method for determining the water absorption by capillarity of porous inorganic materials used for and constituting cultural property. The method may be applied to porous inorganic materials either untreated or subjected to any treatment or ageing.

This European Standard specifies a method for the measurement of the static contact angle of a water drop on porous inorganic materials used for and constituting cultural property. The method may be applied to porous inorganic materials either untreated or subjected to any treatment or ageing.