For a better understanding of the behaviour of old brick masonry in facing the rising damp problem, multiple tests were made in the laboratory: water absorption, moisture content, apparent porosity, temperature and thermal camera imaging on brick masonry and its components: brick and mortar. This has allowed us to determine which of the previous tests is the best in predicting the behaviour of a real wall. In addition, the tests have also helped in defining a process to evaluate the moisture content of walls in a buildings, which is important for heritage restoration projects.

During interventions to improve the energy efficiency of cultural heritage, it is common to use methodologies that are used for current buildings with different thermal behaviour. For this reason, research has been carried out on the thermal behaviour of old brick walls by carrying out thermal flow tests in the laboratory on brickwork specimens, in order to compare the behaviour of handmade bricks and mechanical bricks from more than a century ago, and to analyse the relationship between the values of thermal conductivity, humidity, density and porosity, as well as to compare these results with those obtained by applying the procedure of the EN-1745 standard. It was concluded that bricks behave thermally differently, depending on the manufacturing process: handmade or mechanical, in both types of brick it was found that the higher the moisture content and density were, the higher the brick’s thermal conductivity value. It has also been concluded that old bricks have thermal conductivity values different from those indicated in EN-1745 as a function of density, and that the ratio detected in these specimens in the dry state and in the wet state does not conform to the processes indicated in the standard. With regard to porosity, it is important to note that the greater the closed porosity, the lower the conductivity. It has been concluded that in order to intervene in cultural heritage buildings, it is necessary to carry out a specific study of the behaviour of the systems with which they were constructed.

Interventions in historic brick buildings require an exhaustive analysis of the current characteristics of bricks in order to establish the role performed by these elements in the buildings. This study presents the results of an experimental analysis of the compressive strength of brick specimens extracted from different buildings built in the 19th and 20th centuries in the province of Zamora (Spain). The study analyses specimens with very different characteristics to compare results from different masonry units and manufacturing processes. Specimens are classified into four groups according to their macroscopic and microscopic analyses. Compressive strength results are correlated to the above classification and to the results of density, absorption and open porosity of the samples. The compressive strength results present high variation between clay bricks (9.2–64.4 N/mm²) and between samples extracted from the same brick due to the heterogeneity of the material. Correlations between compressive strength and open porosity, absorption and dry density values are observed, with less dispersion in the case of high sintering level, up to 1000 °C. Finally, the compliance with the current Spanish Technical Building Code with respect to their compressive strength is checked.

To improve the energy performance of restored cultural heritage buildings, it is necessary to know the real values of thermal conductivity of its envelope, mainly of the facades, and to study an intervention strategy that does not interfere with the preservation of their cultural and architectural values. The brick walls with which a large number of these buildings were constructed, usually absorb water, leading to their deterioration, whereas the heat transmission through them is much higher (than when they are dry). This aspect is often not taken into account when making interventions to improve the energy efficiency of these buildings, which makes them ineffective. This article presents the results of an investigation that analyzes thermal behavior buildings of the early 20^th century in the city of Zamora, Spain. It has been concluded that avoiding moisture in brick walls not only prevents its deterioration but represents a significant energy saving, especially in buildings that have porous brick masonry walls and with significant thicknesses.

In the energy efficiency restoration, one of the most important aspects to consider is the loss of heat through the enclosing walls, for which constructive solutions are sought to improve their thermal performance, being usual to place a sheet of insulating material on the inner side of the facade, avoiding intervening on the outside, so as not to alter the appearance of the buildings. This fact is aggravated in the buildings built with brick factory, especially in those belonging to the Historical Heritage whose walls are raised with handmade bricks joined by mortar joints. This type of wall has a high porosity, whose immediate consequence is the absorption of a large amount of water, which is a good conductor of heat, which means that a wall saturated with water has a higher thermal conductance than being dry, increasing the consumption of energy needed to thermally condition the interior. Applying the current regulations, in order to determine the thermal conductivity of the mentioned walls, laboratory tests have been carried out on dry and saturated specimens and also on similar materials. The analytical study of the values obtained from the thermal conductance of the brick factory wall in wet state and in dry state offers data with important variations. The most immediate conclusions are two, firstly that it is necessary to know the state of humidity of the facades to determine the insulating behavior of the same and that to save energy and achieve an effective intervention, it is necessary to act on the outside of the walls, keeping it dry by applying treatments on the facades.