Masonry Repairs on Vintage Buildings

By Stephen A. McDermott

Unfortunately, reviews of masonry façades are seldom performed.  The execution of exterior masonry wall repairs is often times only triggered as a result of water infiltration into a habitable space.  The Brick Institute recommends a periodic inspection every year but masonry structures may generally not be reviewed until someone notices loose, cracked, or displaced masonry.  It is not unusual for masonry to not be reviewed for several decades or longer.

Masonry façades should be evaluated on a regular basis to stem expensive future repairs and to address active water infiltration.  Problematic areas of masonry are typically below wall penetrations such as window openings.  Inattention to proper masonry detailing at windows can also lead to ingress of moisture in masonry walls.  Masonry chimneys and parapets are also typically neglected.

Moisture penetration through exterior masonry will contribute to the breakdown of mortar joints and in turn may affect the overall wall integrity.  This level of deterioration does not occur overnight but takes years of moisture infiltration and freeze-thaw cycles.  Cracked masonry units also contribute to moisture migration through the wall.

Brick masonry is made from clay; clay will absorb water if subjected to large amounts of wind-driven rain.  Stone masonry is not as absorbent as clay masonry but will still transmit moisture.  Clay and stone masonry will dry out over time in warm temperatures.

Deficient masonry walls will allow water to enter the wall at failed mortar joints, cracks and missing or spalled units.  Masonry walls in the northeast are subjected to freeze/thaw effects whichfurther exacerbate mortar deterioration, lateral displacement and cracking of the brick units.  If left unchecked the freeze/thaw process creates additional avenues for water to enter the wall and thereby allows the cycle of deterioration and infiltration to continue.