Historic Preservation - Technical Procedures
Rehabilitating Wood Windows
The Old Custom House/New York, Ny - Gsa/Pbs, 1991
Doors And Windows
Rehabilitating Wood Windows
REHABILITATING WOOD WINDOWS
A. This procedure includes guidance for the rehabilitation
of wood windows. Outlined are the steps one might go
through to complete repairs. Each step is cross-
referenced to one or more procedures which covers the
particular problem. The cross-referenced procedures
should be reviewed prior to beginning window repairs and
should be followed along with recommendations from the
Regional Historic Preservation Officer (RHPO).
B. The steps in the repair of deteriorated sash include but
are not limited to the following:
1. Examination, survey and condition assessment of
2. Removal of existing sash, trim, etc.
3. Repair of deteriorated wood through the use of
epoxies, dutchmen and/or the replacement with new
wood to match the existing appearance.
4. Painting/refinishing sash and trim.
5. Installation of repaired sash.
C. See 01100-07-S for general project guidelines to be
reviewed along with this procedure. These guidelines
cover the following sections:
1. Safety Precautions
2. Historic Structures Precautions
4. Quality Assurance
5. Delivery, Storage and Handling
6. Project/Site Conditions
7. Sequencing and Scheduling
8. General Protection (Surface and Surrounding)
These guidelines should be reviewed before performing
this procedure and should be followed, when applicable,
along with recommendations from the RHPO.
D. For general information on the repair of wood windows see
08610-01-S, "Preservation Briefs: 9 - The Repair of
Historic Wooden Windows."
A. Shop drawings for each type of window, including 1/4-inch
scale wall elevations, typical unit elevations at 3/4-
inch scale, glazing details, and full-size details of
typical composite members, include window rehabilitation,
wood and hardware replacement, reglazing details and
B. The RHPO reserves the right to require additional samples
that show fabrication techniques and construction and
design of hardware and accessories.
1.03 SEQUENCING AND SCHEDULING
A. Rehabilitation of windows shall be completed before doing
any interior restoration/rehabilitation work to insure
weather-tight integrity of interior spaces.
NOTE: See specific procedures for materials and equipment
requirements, and their manufacturers and sources.
A. Conduct a window-by-window survey to determine existing
conditions and identify the specific work needs of each
B. For each window type, the survey should include color
photographs which show design details for comparison to
new work, and existing conditions.
1. Full frame views, both interior and exterior.
2. Close-up views of typical details, both interior
3.02 ERECTION, INSTALLATION, APPLICATION
A. Carefully remove window stops, sash and trim as required.
Remove only those features which cannot be repaired on-
site. All disassembled parts should be indelibly marked
or stamped on hidden parts so they can be returned to
their exact location.
1. See 06440-03-R, "Closing Open Joints in Wood Wall
B. Replace rotted window sills as required.
1. See 08610-04-R, "Replacing a Wood Window Sill"
C. Repair, replace, or rebuild all rotted or deteriorated
wood features. These can include but are not limited to
stiles, rails, muntins, joints, frame, trim. New work
shall match existing profiles or shapes in every respect
and shall be flush with existing adjacent surfaces.
1. See 06300-01-R, "Epoxy Repair for Deterioration and
Decay in Wooden Members"
2. See 08611-01-R, "Sealing Leaky Wood Double-Hung
3. See 06440-01-R, "Repairing Cracks and Checks in
Wood Wall Ornament
4. See 06440-03-R, "Closing Open Joints in Wood Wall
5. See 06440-04-R, "Repairing Scratches, Gouges and
Dents in Wood Wall Ornament"
7. See 09560-03-R, "Dutchman Repair of Wood Floor
D. Remove paint from both interior (where applicable) and
1. See 06400-07-R, "Chemically Removing Paint From
2. See 06400-02-S, "Supplemental Guidelines for
Removing Paint from Interior and Exterior Wood
3. See 06400-09-R, "Removing Paint From Wood Features
Using Thermal Methods"
E. Remove all deteriorated glazing putty and broken glass.
Replace glass and reglaze with a flexible elastomeric
glazing compound. Clean the existing historic glass.
See 08800-01-R, "Replacing Broken Glass in Wood and Metal
F. Reinstall windows. Inspect pull chains and weights at
all double hung windows and adjust, clean or replace as
required to ensure proper operation. Lubricate all
working parts to assure smooth operation.
1. See 08760-01-R, "Repairing Double-Hung Window Sash
Weights and Cords/Chains"
2. See 08712-01-R, "Resetting a Hinge Mortise"
G. Provide weatherstripping as required.
1. See 08500-01-R, "Installing Weatherstripping on
Metal Double-Hung Windows"
H. Refinish both interior and exterior sides of sash, frame
and trim with appropriate paint, stain or natural finish
1. See 06300-01-S, "Primers and Paints for Wood"
2. See 06300-02-R, "Surface Preparation for Painting
3. See 06400-10-R, "Refinishing Interior Wood"
4. See 06310-01-S, "Preparing a Non-toxic Water-
5. See 06310-01-P, "Applying a Water-repellent
Preservative to Wood"
6. See 09900-07-S, "General Guidelines for Painting
Exterior and Interior Surfaces"
7. See 06300-03-R, "Applying a Semi-Transparent or
Opaque Stain to Wood"
1. All window hardware shall be removed, marked for
proper room number and location, boxed or packaged,
and collected in a central location for the
Contractor who shall polish all the hardware before
2. All hardware to be removed before paint stripping,
cleaned to bare metal and repaired to its original
3. Where hardware is missing or damaged, provide new
hardware of same design and material as original
A. Begin and maintain protection and other precautions
required through the remainder of construction period to
ensure that newly rehabilitated window units will not be
damaged throughout the remainder of any restoration or
END OF SECTION