By Rhonda Maas
Thoughtfully restoring old masonry buildings connects us
with our pasts. Carefully maintaining them continues that connection into the
future. Masonry is built to last. A 100-year-old building can easily last
another 100 years with proper attention and care.
One reason why masonry buildings are so long lived is that they
are largely impervious to attack. However, they do have one insidious enemy: water.
Water can infiltrate a building from the roof, parapets, windows, landscaping,
basement window wells, and even chimneys. Any connection between the masonry
and another material can become an entry point for water. The best line of
defense is a one-two punch: Start with quality waterproofing and follow up with
regular maintenance, from top to bottom.
Waterproofing:
what contractors should do
A good mason contractor will assure finished projects have
all the right flashings, adequate drainage and proper joint sealing. Basically,
any open joint needs to be filled.
Starting at the top, gaps between the termination bar of
rolled roofing material and the parapet wall as well as the parapet caps should
be sealed with joint sealant, caulk or mortar, depending on the design and
building material.
Many renovation projects include replacing windows.
Contractors must be sure new windows have proper flashing that sheds water away
from the masonry, instead of channeling it down the face.
Landscaping may seem peripheral, but it can be key to
protecting the building. There should be a dry zone around the foundation, and
the site should be graded to channel water away from the building. Putting
sprinklers and plants right against the masonry increases the risk of water
infiltration. When pavement – for example, a concrete sidewalk – is installed next
to the masonry, the joint where the two meet should be sealed using a material
with adequate movement characteristics, and installed with proper application
techniques to ensure good adhesion.
Finishing at the bottom, take a look at the window wells.
Some old buildings have basement windows below grade. Make sure the window
wells can drain properly. It may be necessary to dig them out and install a
membrane to keep water from seeping into the well and being trapped next to the
foundation.
Maintenance:
what building owners can do
An annual inspection and maintenance program is the most
cost-effective way for building owners to protect investments in older buildings.
Most annual maintenance is relatively simple and inexpensive to perform, but
can save costly repairs down the line.
The cause of water damage I see most frequently also is the
most easily preventable: clogged gutters. These can direct water straight onto
the brick or stone face, saturating it and subjecting it to discoloration and
freeze-thaw damage. Clogged gutters also create ice dams that threaten roofs
and trap moisture. Gutters should be inspected at least once a year to assure they
are free of debris.
Not all drainage clogs are as easily visible. An inspection
should include a search for stair-step cracks in brick walls. These indicate
the ground is saturated and the foundation is shifting. This can happen when a
downspout is clogged or missing, dumping water in the wrong spot. If a drainage
system that discharges underground is plugged, water may be backing up and
damaging the foundation.
Another item for annual inspection is the roof. Roofing
materials shrink as they age, pulling away from the masonry and opening a gap.
These gaps should be sealed and any other roof leaks repaired. Also, check to
see that chimney caps are intact and properly attached and sealed.
Sealant joints in which the grade meets the building façade
should be inspected every year as well. A long-term maintenance plan should
include provision for resealing every few years, as movement and sun exposure
will degrade the material over time.
Finally, basements should be inspected for signs of moisture
such as odors or mildew. Even if not in use, basements need to be ventilated
with outside air.
With proper waterproofing and regular inspections and
maintenance, contractors and building owners can ensure that the historic
buildings they have worked hard to restore and preserve are ready to face the
second 100 years.
Rhonda Maas is the
co-founder and president of Building Restoration Specialties Inc. (BRS), which
specializes in masonry restoration, preservation and conservation of historic
buildings. Founded in 1986, BRS has a bonding capacity of about $7 million, and
is positioned to handle projects ranging from $2,000 to more than $2 million. Learn more at www.brsrestores.com.
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