Wooden fixed louver vents were custom-made and installed. The easily fabricated louvers were sized to fit the lower sash opening 34 1/2" wide by 34 1/4" high on the first floor, while those for the smaller second floor windows were only 25 1/4'' high. Full units were installed in all single-sash basement windows, since the window area was much less and the moisture problems more severe (see figure l). At the same time, the three attic windows were also replaced with full louvers to encourage thorough multi-level ventilation.

Custom-built wooden louvers were selected over stock, pre-fabricated metal vents for the following reasons: most pre-fabricated vent systems would require modifications of the historic jamb in order to get a secure fit; a single style metal unit could not be found to fit the variety of opening sizes and the depth of the jamb; costs would be greater than making the custom units; and most important, it was felt that the thin gauge metal units offered little or no deterrent to unlawful entry. The wooden units presented a more secure system,

The louver frame was designed to fit snugly into the existing sash tracks and simultaneously to secure the glazed upper sash. An

Figure 2. Section of the wooden louvers shows the simple manner in which they were made and assembled. Drawing: Thomas Vitanza

added benefit of the 6'' stock width is that it provided a fairly rigid - and thus secure - louver frame. The louver frame was constructed of 1'' x 6'' shelf grade northeastern white pine; the louver slats were made from 1'' x 8'' pine (see figure 2). The spacing of the louver slats did not exceed 4'' in order to provide additional lateral strength (and security) to the frame. The relative closeness of the slats also would make it more difficult to kick out the grade level units. The slats were set into the frame at a 45 degree angle by routing a 1/4 deep dado cut into the jamb of the louver. The exposed edges of the slats were plumb cut in order to create a water drip on the exterior.

Prior to assembly, the louver members were primed using an alcohol base paint in order to get at least one protective coat on all surfaces. After assembly, they were given one shop coat of oil base exterior house paint. A final coat was applied afterinstallation. For aesthetic reasons. the paint color used on the sash and trim was selected for the final coat on the louvers (see figure 3).

In order to secure the vents in place, common 6d galvanized box nails were driven through the louver jambs into the sash tracks of the historic window jambs. To keep the jamb and stops from being damaged by the louver installation, temporary blocking was set between the parting bead and the inner and outer stops (see figure 4). By attaching the vents in this location, little damage was done as the nails were driven into the sash track rather than an exposed portion of the jamb. Once the building is returned to use, the lower sash will be installed and the nail holes will be filled with wood putty. Since the nails were driven in on the interior of the building, nearly 3'' from the exterior wall, adequate security was achieved without driving the nails all the way in. Thus it will be relatively easy to grab onto the nail heads and back them out when the vents are eventually removed.

Figure 4. The lower sash (Figure 4a) were removed to permit installation of the louvers. To minimize damage to historic fabric in installing the louvers, temporary blocking was set between the parting bead and stops prior to nailing the units in place (Figure 4b). Drawings: Thomas Vitanza and Christina Henry.

After the louvers were secured in place, 1/16'' mesh copper wire screening was installed on the interior of the louver frame using a l/2'' square wood frame. The screening is an integral part of the louver design. This seemingly minor detail was necessary to prevent the recurrence of insect, bird, and rodent infestation (see figure 5). The 1/16 '' mesh was specified to keep out the ever-present mud-dauber wasp, whose hive-building instincts have no regard for historic plaster or paint.

The cost of constructing and installing the louvers in 27 window openings was around $ l ,800, including 17 full size louvers, 7 basement and 3 attic units. This work was undertaken concurrently with the construction and installation of the reconstructed window sash and repairs to the frames, sills, jambs, and surrounding brickwork. The total cost of the window work was less than $9,000, involving 3l window openings.

Figure 5. Screening was attached to the back side of the louvers to prevent the recurrence of insect, bird, and rodent infestation. Photo: Charles Fisher