Nativity of the Virgin Mary, Cohasset

THE CHALLENGE

The Nativity-Assumption of the Virgin Mary Greek Orthodox Church was constructed in 1900.  The exterior bearing walls were built from granite blocks in an Ashlar pattern.  The gable roof is in the shape of a cross with two large dormers.  A mason was hired to repoint and seal the stone masonry concurrently with the interior restoration work in the summer of 2008.  However, water leakage continued to occur in the church and in the bell tower beginning shortly after the work was completed, and was still occurring at the time of our evaluation, damaging the interior plaster walls as well as the stone masonry construction.

CBI’S SOLUTION

CBI reviewed the existing conditions of the water leakage on the interior of the building and the exterior to view the conditions of the asphalt shingles, copper roofing, and stone masonry.  The original slate roofing was replaced with architectural grade asphalt shingled around 2004 and the interior of the church was restored and repainted in the summer of 2008. 

In general, the main source of the leakage into the sanctuary of the church was from water penetrating the stone masonry through poorly pointed and open mortar joints and cracks in the mortar.  Numerous mortar joints were found with loose pointing mortar due to poor repointing work from the previous mason as well as earlier masons. 

CBI recommended cutting out 100% of the joints in the stone masonry 1” minimum and repointing the joints with a Type N mortar.  Additionally, we recommended restoring the copper counterflashing and resealing the window perimeters.