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The results of the mapping of the south-west wall of the Zvartnots complex show, that back-weathering, concentrated at the lower part of the wall is the main damage form covering more than 13 square meters of ashlar and more than 70 % of the whole study object (Fig. 5c).

These damages can be clearly associated with the effloresences of salts. Using test stripes, high amounts of sulfate (> 1,600 mg/l), chloride (1,000 mg/l) and nitrate (500 mg/l) could be detected. Loss of material, rounding and scaling only took place at around 3.5 m² of the investigated wall. Biological growth is not observable (Fig. 5c).

In a comparison of both buildings, which were built with comparable rock materials, values between 0–15 RF and 0–200 % WME speak for a largely intact condition.

For the Zwartnots cathedral electrical conductivity and capacity shows critical values in all measurement points by reaching more than 15 (% WME) in case of the conductivity and more than 400 (RF) for the capacity.

At the Avan Cathedral crack formation is the predominant weathering form, following by back-weathering and scaling. In Figure 6, these damage forms are depicted at one half of the façade, where also no relevant salt weathering was found. The electrical conductivity and capacity show critical values only in the lower part of the building, which is also partly effected by rising dampness (Fig. 6).