The performance of shelters for the conservation of archaeological sites in dry and warm climates: the case of Complutum

Abstract

Excavated archaeological sites are frequently exposed to damaging environmental conditions, which could lead to rapid decay especially for vulnerable heritage such as mosaics. One of the most common solutions is the construction of shelters; however, some may not behave as expected, either because they do not protect adequately or induce decay. An environmental monitoring programme was undertaken inside and outside the two types of shelters at the Roman archaeological site of Complutum (Alcala de Henares, Spain) from May to September in 2018 and 2019. Hourly temperature and relative humidity readings collected by data loggers, together with rainfall data from a local meteorological station, have been comparatively assessed to better understand the consequences of sheltering in dry and warm areas. The results indicate that both shelters are avoiding further decay by keeping a more stable environment in relation to outside, although the more enclosed structure would be the most suitable one.