Greetings!
In this issue of Building Solutions, we continue to feature Case Study articles on our historic and period restoration projects, this time describing the restoration of a portion of the tower at the New Hope Baptist Church in downtown Boston. We also include a Building Basics article on repointing brick masonry.
We trust that you will benefit from the information provided in this publication. If you have any comments or questions, we can be reached at 617-445-0274 or at www.abbotbuilding.com.
Sincerely, Michael Norman
Vice President
Abbot Building Restoration Company, Inc.
617-445-0274
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Abbot Restores Portion of
Historic New Hope Baptist Church Tower
 Abbot Building
Restoration recently completed restoration of a portion of the tower at the
historic New Hope Baptist Church on Tremont
Street, Boston, MA. As part of a renovation, Abbot was contracted to
investigate and resolve a severe leakage problem within the tower.
On the left
face of the tower, Abbot restored the stained glass windows on the first floor as
well as all of the wood windows above being careful to maintain the historic
integrity of the building. In addition, Abbot selectively repointed the mortar
joints.
In the rear of
the tower, Abbot removed all of the mortar joints and repointed the entire section,
including the area that was causing leakage of water into a stairwell. Abbot also restored all of the windows on
that side.
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Founded in
1938 at a location not far from where it currently sits, the New Hope Baptist Church is a vital member of Boston's South End historic community. It has grown
from a membership of twenty to become one of Boston's leading Black Baptist
Churches.
In 1968, the congregation purchased
and remodeled its current home -- the Tremont Street Methodist Church building
-- located at the corners of West Concord and Tremont Streets. Constructed in 1862, the building was
designed by the renowned Boston architect Charles Howland Hammatt Billings in
the traditional Gothic Style. This
was the first church in the Boston area to be built of Roxbury 'puddingstone',
a popular building material in the mid-nineteenth century for religious
buildings.
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Getting to the Point
In many of our case studies, we refer to the term "repointing" of brick
masonry surfaces. Repointing is
the process of renewing mortar joints in masonry construction. Over time,
weathering and decay may cause voids in the mortar joints between brick masonry
units allowing the undesirable ingress of water. Water entering through these
voids can cause significant damage through freeze/thaw cycles, and from salt
dissolution and deposition.
The Repointing Process
 The repointing process
begins by removing damaged pointing to a depth equal to or slightly more than
the width of the joint, or to the point where sound mortar is reached. Depths
greater than 2-1/2" or 4 cm should be filled in several passes, allowing
the mortar to cure for at least 24 hours. The joint profile should be as
rectangular as possible as the new pointing mortar should be allowed ample
opportunity to bond with the masonry unit. Note that sound mortar normally does not need to be removed
from a building during the repointing process, although such a practice is
common.
Removal of old mortar
between joints is done carefully to avoid damage to masonry units. On very old
buildings with soft materials, such as under-fired brick, removal by hand is
often the most effective to avoid damage. Hard Portland cement mortar is
usually removed with a grinder or power circular masonry blade, taking care not
to damage the masonry units. Vertical joints in most cases are always done by
hand or with small power chisels.
Potential Problems
Poor repointing work often
raises the level of the mortar joint above the face of the masonry unit, which
causes the mortar edge to feather. Such a process is aesthetically undesirable
and can cause erosion problems. In addition, depending on the nature of the
mortar, mortar that rises above the level of the face of the masonry unit can
participate in damaging the corner of the masonry unit. In these cases, deteriorated
mortar is often not removed to a sufficient depth.
Mortar Selection
It is essential that the
mortar used for repointing have similar characteristics to the
original mortar used in a building, including color and texture, permeability, compressive strength,
and coefficient of thermal expansion. For example, if a soft lime-based mortar was originally used, the most
appropriate repointing material should also contain a large amount of lime. The
use of Portland cement mortar for repointing on older buildings with soft
masonry units can cause significant damage due to physical incompatibilities.
An architectural engineering firm
can perform a mortar analysis in order to make recommendations for replacement
mortar that is both physically and aesthetically compatible with the building.
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About Abbot Building Restoration
Abbot Building Restoration Company, Inc., has been providing quality construction and restoration services for more than 50 years. We have built our reputation on a wealth of experience, a strong work ethic, a high level of technical expertise, and longstanding relationships with a variety of clients in the public, institutional, and commercial sectors.
We specialize in restoring and preserving the integrity of the building envelope of aging and problem structures in the greater Boston area. We also provide remedial weatherproofing services to correct construction deficiencies in newer structures. Our specific areas of expertise include:
o Masonry construction and repairs
o Weatherproofing services
o Caulking
o Pointing
o Waterproofing
o Special coatings and sealants
o Roof repair, replacement, or resurfacingSignificantly,
Abbot is a family-owned business representing four generations since
its inception in 1936. The current leadership team takes great pride
in the company's strict attention to detail and family-oriented management approach. Call Abbot today at 617-445-0274 to arrange for a FREE INSPECTIONAL SURVEY, or visit our web site at www.abbotbuilding.com. |
Abbot Building Restoration Company, Inc.
28 Allerton Street, Boston, MA 02119
Tel: 617-445-0274 · Fax: 617-445-0277
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IN THIS ISSUE
Case Study
Abbot recently restored a portion of the tower at the New Hope Baptist Church in downtown Boston. See full article below.Building Basics
Repointing is
the process of renewing mortar joints in masonry construction. Over time,
weathering and decay may cause voids in the mortar joints between brick masonry
units allowing the undesirable ingress of water. See full article below.
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Visit Our
Updated Web Site
We recently updated our web site to include descriptions of our most recent projects as well as pertinent industry articles we authored in the New England Real Estate Journal.
To visit our web site, click on the link below.
www.abbotbuilding.com
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