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Moravian College • Preservation Master Plan
system or scupper, which in turn directs water to
an internal or external downspout. The downspout
carries water down to the foundation and directs
runoff into an underground drain, French drain,
grade level channel, or splash block in order to
move the water away from the building foundation.
Ideally, the roof and roof drainage system, from
rooftop to site or storm sewer, is designed and
maintained as one system.
Typical Roof and Roof Drainage
System Conditions
Roofs throughout the Moravian College campus
include a variety of materials and shapes ranging
from gambrel to gabled to flat. Roofing materials
include traditional slate or wood shingle, as well
as modern asphalt shingle, built-up, and EPDM
roofing. Ornamental features, such as dormers,
belvederes, and cupolas, add visual interest. Roofs
typically drain to hanging half-round gutters
and round downspouts, which drain either to
underground drain lines or to grade. In a few cases,
the roofs drain directly to grade with no provision
for roof-edge collection.
Roofing materials are undergoing minor
deterioration, particularly at slate roofs where
slates are loose, broken, or missing. On a few
buildings, gypsum can be seen as a white crust on
slate surfaces, which is an indication of long-term
weathering and approaching end-of-life service
for the material. Metal flashing is rusting in a few
locations. Roof leaks have led to damage in some
interior spaces and deterioration of exterior walls.
The most severe and prevalent problems of roofs
at Moravian College are related to problematic
roof drainage systems. Gutters are bent, clogged,
or inadequately sloped and chronically overflow.
In a few places, entire downspouts or bottom
sections of downspouts are missing. Where
they are intact, downspouts fail to direct water
away from the building foundations because of
inadequate or clogged underground drainage,
or because they release water at points that are
close or directly against the building foundation.
Deteriorated masonry, open or eroded masonry
joints, rising damp in masonry walls, salts forming
on masonry surfaces, biological growth, wood rot,
ponding water, and soil erosion are indicative of
long-standing issues and a general lack of focused
cyclical maintenance.
In the few locations where the roofs are designed
to drain directly to the ground, site drainage must
often be improved. Underground drain lines are
frequently clogged. Many underground lines are
composed of terra-cotta pipe that becomes broken
or displaced through ground movement and root
action.
The relatively simple task of regular inspection is an
urgent priority: the gutters and downspouts of all
historic buildings should be inspected and cleaned
at least twice yearly. Moisture-related problems
affecting roof systems should be properly diagnosed
and corrected at their source. Missing, bent,
sagging, and inadequately sloped gutters should
be replaced. Missing downspout components must
be replaced immediately or temporary measures
installed to redirect water drainage. Problems with
site drainage must be holistically investigated and
properly addressed in order to improve conditions
at building foundations. Roof and roof drainage
system work should become a priority and should
be accompanied by implementation of cyclical
maintenance and monitoring.
Roof and Roof Drainage System
Inspection
The best course of action in maintaining a roof
and its drainage system is periodic inspection and
repair. The baseline roof inspection should include
a yearly inspection of the entire roof system and
twice-yearly removal of debris from gutters and
downspouts. The yearly evaluation should be
comprehensive and examine not only exteriors,
but also the attic, basement, and crawl spaces. Roof
components such as flashing, gutters, downspouts,
hatches, and mechanical equipment should be part
of this inspection. Inspection should include testing
and/or observation during major rain events to
ensure that the roof drainage system successfully
diverts rainwater away from the building.
Underground drains are especially susceptible to
failure, largely because they are difficult to inspect
and maintain. Remote inspection techniques are
often required, such as a flexible rod equipped with
a radio transmitter or fiber optic camera. By the time
problematic conditions are detected, substantial and
expensive damage may have occurred. Therefore,
the first line of defense is regular roof inspection.
A roof system in good condition should meet all of
the following criteria during inspection.
John Milner Associates • October 2009 • Chapter 9 • Building Guidelines • 299