When parts of the frame or sash are so badly deteriorated that
they cannot be stabilized there are methods which permit the retention
of some of the existing or original fabric. These methods involve
replacing the deteriorated parts with new matching pieces, or
splicing new wood into existing members. The techniques require
more skill and are more expensive than any of the previously discussed
alternatives. It is necessary to remove the sash and/or the affected
parts of the frame and have a carpenter or woodworking mill reproduce
the damaged or missing parts. Most millwork firms can duplicate
parts, such as muntins, bottom rails, or sills, which can then
be incorporated into the existing window, but it may be necessary
to shop around because there are several factors controlling the
practicality of this approach. Some woodworking mills do not like
to repair old sash because nails or other foreign objects in the
sash can damage expensive knives (which cost far more than their
profits on small repair jobs); others do not have cutting knives
to duplicate muntin profiles. Some firms prefer to concentrate
on larger jobs with more profit potential, and some may not have
a craftsman who can duplicate the parts. A little searching should
locate a firm which will do the job, and at a reasonable price.
If such a firm does not exist locally, there are firms which undertake
this kind of repair and ship nationwide. It is possible, however,
for the advanced do-it-yourselfer or craftsman with a table saw
to duplicate moulding profiles using techniques discussed by Gordie
Whittington in "Simplified Methods for Reproducing Wood Mouldings,"
Bulletin of the Association for Preservation Technology, Vol.
III, No. 4, 1971, or illustrated more recently in The Old House,
Time-Life Books, Alexandria, Virginia, 1979.
The repairs discussed in this section involve window frames which
may be in very deteriorated condition, possibly requiring removal;
therefore, caution is in order. The actual construction of wooden
window frames and sash is not complicated. Pegged mortise and
tenon units can be disassembled easily, if the units are out of
the building. The installation or connection of some frames to
the surrounding structure, especially masonry walls, can complicate
the work immeasurably, and may even require dismantling of the
wall. It may be useful, therefore, to take the following approach
to frame repair: 1) conduct regular maintenance of sound frames
to achieve the longest life possible, 2) make necessary repairs
in place, wherever possible, using stabilization and splicing techniques,
and 3) if removal is necessary, thoroughly investigate the structural
detailing and seek appropriate professional consultation.
Another alternative may be considered if parts replacement is
required, and that is sash replacement. If extensive replacement
of parts is necessary and the job becomes prohibitively expensive
it may be more practical to purchase new sash which can be installed
into the existing frames. Such sash are available as exact custom
reproductions, reasonable facsimiles (custom windows with similar
profiles), and contemporary wooden sash which are similar in appearance.
There are companies which still manufacture high quality wooden
sash which would duplicate most historic sash. A few calls to
local building suppliers may provide a source of appropriate replacement
sash, but if not, check with local historical associations, the
state historic preservation office, or preservation related magazines
and supply catalogs for information.
If a rehabilitation project has a large number of windows such
as a commercial building or an industrial complex, there may be
less of a problem arriving at a solution. Once the evaluation
of the windows is completed and the scope of the work is known,
there may be a potential economy of scale. Woodworking mills may
be interested in the work from a large project; new sash in volume
may be considerably less expensive per unit; crews can be assembled
and trained on site to perform all of the window repairs; and
a few extensive repairs can be absorbed (without undue burden)
into the total budget for a large number of sound windows. While
it may be expensive for the average historic home owner to pay
seventy dollars or more for a mill to grind a custom knife to
duplicate four or five bad muntins, that cost becomes negligible
on large commercial projects which may have several hundred windows.
Most windows should not require the extensive repairs discussed
in this section. The ones which do are usually in buildings which
have been abandoned for long periods or have totally lacked maintenance
for years. It is necessary to thoroughly investigate the alternatives
for windows which do require extensive repairs to arrive at a
solution which retains historic significance and is also economically
feasible. Even for projects requiring repairs identified in this
section, if the percentage of parts replacement per window is
low, or the number of windows requiring repair is small, repair
can still be a cost effective solution.
"The Repair of Historic Wooden Windows" an Historic Preservation Brief
