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We are in the process of translating WTA-Guidelines of international interest into English.


The English versions are only available as downloads from our sales partner Fraunhofer-Informationszentrum Raum und Bau IRB. A link to the webside of IRB and the download offer is to be found next to the guideline.


The following guidelines are availabele in English language:

Non-destructive desalination of natural stones and other porous building materials with poultices

WTA-Guideline 3-13-01/E                   Download



The present WTA-Guideline describes the different poultices procedures that can be used for the reduction of the salt content in stones, masonry and porous mineral materials. The optimal boundary conditions were developed for both drying and permanently wet poultices based on the results obtained through recent research and the experience gained from many applications from actual case studies.

The methodology for selection of the most appropriate procedure for a given buil-ding is described as well as that for evaluating (quantitatively) the effectiveness of the procedure. Both the advantages as the disadvantages of the procedures and materials to be used are discussed with the aim of achieving a successful desalina-tion. Also discussed are the evaluation criteria to be applied. lt is stressed that desalination procedures are to be carried out only by qualified technicians and that the existing WTA-Guideline on the restoration of natural stone should be taken into account.

Simulation of heat and moisture transfer

WTA-Guideline 6-2 Edition: 12.2014/E                  Download



High moisture in building components can result in hygienic problems, damage to materials and energy losses. The first edition of this guideline provided interna-tionally recognised methods for realistic analyses of transient temperature and moisture behaviour in building components. It has served as basis for an interna-tional standard on this topic. This new edition of the guideline accounts for the advances in science and technology. It provides specifications for numerical simulation methods and recommendations for their practical application. The underlying model descriptions and necessary material parameters are specified. Furthermore, the choice of climatic boundary conditions, the accuracy check procedure and the documentation of input and output data is described. Contrary to the standardised steady-state Glaser method, the numerical simulation includes the heat and moisture storage of building materials as well as latent heat effects by condensation or evaporation and the parallel occurrence of vapour diffusion and liquid transport. The climatic boundary conditions are temperature, relative humidity, radiation and precipitation. The hygrothermal material parameters are generally taken from the database provided by the distributor of the simulation programme. They may also be determined by appropriate laboratory tests or approximated from standard material data.

Internal thermal insulation according to WTA I: planning guideline

WTA-Guideline 6-4 Edition: 10.2016/E                  Download



Internal thermal insulation added retroactively has an especial influence on the behaviour of the building with respect to building physics. Particular attention should be paid to vapour diffusion from inside to out-side, because of likely condensation at the former inner surface of the wall, and because of the reduced drying potential of the external wall after wetting by driving rain.

This guideline is part of a series of guidelines which deal with these specific aspects of moisture transfer. General planning suggestions are made and possible risks are defined and discussed. A verification of moisture protection is vital to fully assess internal thermal insulation measures and to avoid damage resulting from the intervention.

In general, this verification of moisture protection should be conducted using computer simulations of the coupled heat-moisture transport according to WTA guidelines 6-1, 6-2 and particularly 6-5. A simplified verification procedure is presented, and the necessary boundary conditions are determined.