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Moravian College • Preservation Master Plan
still vulnerable to decay. All stone can be damaged
by salts, freeze/thaw cycling, inappropriate or hard
mortars, harsh chemical or abrasive cleaning, and
improper coatings. The local stone used on many of
Moravian’s buildings contains iron ore, resulting in
staining reactions between the stone and rainfall.
Limestone is used as trim material for window sills
and surrounds, water tables, capstones, and steps.
Indiana limestone is a buff-colored homogeneous
limestone with few mineral inclusions. It is so
regular in color and texture that it can easily be
confused for cast stone. The fineness of Indiana
limestone makes it ideal for carved sills and
capstones.
Slate is also sometimes used for terraces and steps.
Slate is a metamorphosed sedimentary rock that
tends to delaminate along natural bedding planes.
Slate is a durable paving material, but is susceptible
to deterioration from salts.
Brick
Brick construction is used for the majority of
historic buildings at Moravian College, and is
used as ornament on some of the stone buildings.
Bricks vary according to their composition and
manufacturing process. Early brick making
technology produced bricks of varying quality.
The quality of the brick used in historic buildings
varies considerably, depending upon the materials
used, shaping methods, firing quality, and other
manufacturing considerations. The better quality
bricks were used for exposed, exterior brick. The
softer, salmon-colored bricks were used in the
construction of inner walls or exterior walls that
were meant to be covered with stucco.
Like a loaf of bread, bricks have an outer crust and
a softer inner material. Without the outer crust, the
inner brick is vulnerable to rapid deterioration.
Removal of the outer crust by harsh abrasive or
chemical cleaning greatly reduces the durability of
the original bricks. Brick functions best when laid
with bricks of a similar type and with a mortar mix
that is carefully matched to the brick type.
It is important that brick masonry be protected
from water infiltration through adequate roofing
and site drainage. Bricks are porous and can absorb
moisture much like a sponge. Water infiltration can
cause freeze/thaw damage to bricks in cold weather.
Water from the ground can carry salts in solution
into the brick masonry, which can cause internal
stresses as the salts form during evaporation.
Waterproofing coatings are not recommended
for brick masonry. They are often responsible for
trapping water within the masonry rather than
keeping it out.
Individual brick units may be damaged by the
corrosion of embedded metal elements and
structural stresses. Embedded metal materials,
such as structural steel angles, metal anchors, and
through-wall pipes, will corrode in the presence
of water. The expanding corrosion products have
enough force to crack brick units and even seriously
disrupt brick masonry. Structural concerns, such as
settlement, may shift an entire wall causing cracking
through brick units and joints. Any masonry
disruption creates new avenues for water to enter
the building, which leads to further deterioration.
Typical Masonry Conditions
Historic masonry conditions throughout Moravian
College’s campus are good overall with some
serious, ongoing masonry deterioration. Water
infiltration of masonry is widespread throughout
Moravian College’s historic buildings, caused by
problems with both roof and site drainage. Affected
areas show mortar loss, biological growth, and
rising damp at the base of walls. In combination with
salts and freeze/thaw forces, water infiltration has
caused wholesale disintegration of stone and brick
units. Masonry is further disrupted by structural
movement, which causes settlement-type cracking
through both joints and stone or brick units.
Masonry has also been damaged by HVAC and
electrical alterations. At some locations, vents
have been cut through the existing masonry walls
during HVAC upgrades. This work has disrupted
the surrounding masonry, which has been
inappropriately repaired in several cases. Electrical
cables have been directed out through holes in
the masonry walls and strung along the face of
the buildings. These conditions could be avoided
through more sensitive and holistically planned
renovations.
Masonry Inspection
The best course of action to maintain masonry is
cyclical inspection and repair. A yearly baseline
inspection should be comprehensive and examine
building exteriors and interiors, particularly in
attics and basements. Water penetration is the major
source of masonry damage. Although masonry is a
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