ABSTRACT
Investigation of the problems of leaks in the colonnade of the stylobate of St. Isaac’s Cathedral, located at St. Petersburg, St. Isaac’s Square, 4. Study of previous studies over the past 120 years. The purpose of the survey was to identify the causes of the destruction of the marble facade of the stylobate and waterlogging of the brickwork under the columns of the drum. The survey of the structures of the colonnade of St. Isaac’s Cathedral was carried out by designers and a group of restorers of stone architecture in 2019 - 2020 in connection with the planned restoration repairs.
