Deterioration mechanisms of coral limestone structure of the Convent and Minor Basilica of San Francisco de Asís and product testing for its conservation

Abstract

The San Francisco de Asis Convent and Basilica Minor, singular
and anthological exponent of the Havana religious architecture of the XVIII
century, is located at what was called before the bay reef. At this moment this
edification has deterioration problems in its stone walls due fundamentally to
the humidity. The deposition of atmospheric pollutants and biological organism’s
growth is joined to this effect, causing an appreciable damage of stone. On the
other hand, this building is sited in a heavy traffic urban area near the sea and
industries, that is, the environment presents a certain pollution level, it could
have a negative effect on the stone. In the present paper, deterioration of this
structure is characterized. Temperature and humidity were determined in the
walls and related to the amount and time of fallen rain. At the same time, atmospheric
pollutants are determined and the efficacy of hydrofuge commercial
products on the stone protection is tested. It is confirmed that three weathering
mechanisms of the stone possible to occur in Cuba are manifested: action of
salts, of biota, and of pollutants of acid character.