Abbot Restores Boston South End Mixed-Use Complex

Abbot recently completed restoration of the façade of a mixed-use complex at 56 Berkeley Street in Boston's historic South End district.

The complex consisted of a new structure built on a vacant lot that was adjacent to an existing building. The existing building was renovated and connected to the new building to create multiple condominium units on the upper floors and retail space at the ground level.

As part of the construction project, Abbot was contracted by the building owner to renovate the brick façade of the existing building. The building was constructed of two layers of brick that were anchored together to form the outer wall. The bricks above the storefront space had dislodged from the back-up bricks and were in need of repair. The original specifications called for reinforcement pinning of the outer brick layer to the back-up layer. However, upon further investigation, it was determined that the outer bricks had dislodged too severely and would need to be removed and reinforced before they could be reinstalled.

Abbot removed the outer layer of brick from the top of the second floor windows to the roofline, and performed a special pinning process by drilling through the back-up brick and securing spiral pins with plates to the interior steel studs to reinforce the outer brick layer. Abbot then reinstalled the original bricks to maintain the historical aesthetics of the building.

In addition, the ornamental header stones above second floor windows were severely deteriorated. Abbot removed one of the stones for use as a pattern to manufacture three new stones in a matching color to the original stones, and then installed the new stones to complete the project.

Moisture Prevention in Architectural Masonry Walls  

Architectural concrete masonry units have an irregular surface that gives them their aesthetic appeal. However, the irregular surface can also make it difficult for the top cap to conform to the surface and seal out wind driven rain. One precaution that may be taken is to use a flashing material, such as a self-adhering flexible product, under a metal cap. This will help to prevent moisture that may penetrate the metal cap from entering the core spaces in the block.

Another good practice is to use a standard concrete masonry unit for the top course in place of the architectural unit.  This allows the vertical legs of the metal top cap to conform to a regular, vertical surface, and makes it easier to caulk under the cap's drip edge to form a seal between cap and masonry. Even a half-high unit can be used as most of it is covered by the top cap, avoiding visual distraction.

It is also prudent to detail a drip edge on the cap to direct the water away from the wall surface, and include proper laps on both the cap and the flashing.