installed over wood boards and lath, and later over metal
lath. Old metal lath is subject to rust. In repairing
stucco, it is best to use modern metal lath, installed on
top of the old wood lath if possible. Test-patch stucco
to recapture texture and degree of graininess of original,
from sand to pebble finish. Stucco may crack or fall off
if the keys fail because of rust, structural deformation,
Brick Veneer Over Wood Lath. Brick veneer is subject to
bowing, cracking, and problems similar to those of stucco.
Problems are less likely when the brick is backed by CMUs
as in modern construction.
Removing Permastone, Asphalt, or Asbestos Siding. In
order to decide whether and when to remove asphalt siding,
it is necessary to know how much damage is underneath the
siding. Permastone should be removed whenever the
opportunity arises. Asbestos siding must be referred to
Vinyl and Aluminum Siding. Vinyl or aluminum siding
should not be used on historic buildings. From the
standpoint of historic preservation, there are three
important reasons to avoid such sidings:
1) It changes the historic appearance of the building
because the texture and proportions of the new boards are
different from the original wood siding. Worse yet, it
may hide historic features such as cornices, window
moldings, or carvings.
2) The siding conceals existing or ongoing damage to
the walls and original siding and makes repairs more
3) The installation process itself may damage the
original siding or other historic features.
Studies have shown that, in the long term, it is not
more economical to install and maintain aluminum or vinyl
siding than it is to keep wood siding in good repair.
Artificial sidings are not maintenance-free. They peel,
pit, split, bend, and fade. Consequently, they may
require repair or repainting in only a few years, and
usually they must be replaced entirely within 20 years.
Although they are sometimes advertised as being energy-
efficient, aluminum and vinyl sidings have no significant
Painting Exterior Wood Walls. Whenever possible, clean
wood walls; do not paint them. Paint when necessary; do
not leave wood bare. Finish the walls with paint or stain
as found in the original. When repainting, you may want
to use the historic colors. A specialist in paint color