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Historic Preservation - Technical Procedures
Supplemental Guidelines For Specifying Repairs To Damaged Woodwork
Tacoma Union Station Courthouse/Tacoma, Wa - 1990
Wood And Plastics
Supplemental Guidelines For Specifying Repairs To Damaged Woodwork
SUPPLEMENTAL GUIDELINES FOR SPECIFYI= NG REPAIRS TO DAMAGED
A. This procedure provides supplemental guidelines to be
used when specifying any type of repair to damaged
woodwork. Guidelines for materials, fabrication and
general guidelines for installation are included.
B. Specifications for the repair of woodwork shall include
all work, materials and equipment requir= ed to:
1. Carefully remove required woodwork and securely
reinstall it to its origi= nal place and position.
Use experienced riggers for the removal and
transportation of woodwor= k.
2. Repair woodwork to conservator quality standards.
3. Document work done through photography.
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 Precaution= s
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 Regional Historic
Preservation Officer (RHPO).
A. American Society for Testing and Materials (ASTM), 100
Barr Drive, West Conshohocken, PA 19428, (610) 832-9585
or FAX (610) 832-9555.
A. Wood Treatment Data: Submit chemical treatme= nt
manufacturers' instructions for handling, storing,
installation, and finish of treated material.
1. Non-Pressure Preservative Treatment: Include
certification stating chemical solution and
submersion period used and affirming compliance
with indicated treatment standards.
2. Fire-retardant treatment data for material
impregnated by pressure process to reduce
combustibility. Inc= lude certification by
manufacturer that treated materials comply with
B. Restore twenty square feet or five linear feet (or
quantity as appropriate) of each wood type to be restored
for review by the RHPO before proceeding with all
restoration. Where new wood must be used to match
existing to repair or infill damaged wood, install twenty
square feet or five linear feet (or quantity as
appropriate) in its final location for review by the RHPO
before proceeding with all repair.
C. Shop Drawings: For new woodwork, submit shop drawings
showing location of each item, dimension= al plans and
elevations, large scale details, attachm= ent devices and
D. Quality Certification: Submit woodwork manuf= acturers'
(fabricator's) certification, saying that fabricated
woodwork complies with quality grades and other
E. Field Measurements:
1. Where woodwork is shown to be fitted to other
construction, check actual dimensions of other
construction by accurate field measurements before
manufacturing woodwork; show recorded measurements
before final shop drawing= s. Coordinate
manufacturing schedule with construction progress
to avoid delay of work.
2. Where field measurements cannot be made without
delaying the work, guaran= tee dimensions and proceed
with manufacture of woodw= ork without field
measurements. Coord= inate other construction to
ensure that actual dimens= ions correspond to
1.04 QUALITY ASSURANCE
A. Installer Qualifications: Arrange for instal= lation of
architectural woodwork by a firm that can show successful
experience in installing architectural woodwork items
similar in type and quality to those required for this
B. Architectural Woodwork Institute (AWI) Quality Standard:
Comply with applicable requirements of "Architectural
Woodwork Quality Standards" publish= ed by the
Architectural Woodwork Institute unless otherwise
C. Testing and Site Inspection: Conduct tests in the
presence of the RHPO, using all procedur= es, materials and
equipment needed to carry out the work.<= br>
1.05 DELIVERY, STORAGE AND HANDLING
A. Packing and Shipping: Do not deliver woodwork until
painting, wet work, grinding, and similar operations that
could damage, soil or deteriorate new woodwork have been
completed in installation areas. <= br>
B. Storage and Protection: If woodwork must be stored in
other than installation areas, store only in areas whose
environmental conditions meet requiremen= ts specified in
Section 1.06 Project/Site Conditions below.
1.06 PROJECT/SITE CONDITIONS
A. Environmental Requirements:
1. Provide adequate ventilation, use of respirators
and protective clothing by workers, and sealing off
work areas during the removal process.
2. Woodwork manufacturer and installer shall advise
contractor of temperature and humidity requirements
for woodwork installation and storage areas. Do
not install woodwork until required temperature and
relative humidity have been stabilized and will be
maintained in installation areas.
3. Environmental Conditions: Obtain and comply with
woodwork manufacturers' and installers coordinated
advice for optimum temper= ature and humidity
conditions for woodwork during its storage and
installation. Do not install woodwork until these
conditions have been attained and stabilized so
that woodwork is within plus or minus 1.0% of
optimum moisture content from date of installation
through remainder of construction period.
1.07 SEQUENCING AND SCHEDULING
A. Coordinate the work in this specification with
appropriate work of other specifications to ensure proper
scheduling for fabrication and installat= ion of the work
B. Verify all dimensions in the field before fabricat= ion of
all architectural woodwork to assure proper fit.
A. Wood Moisture Content: Provide kiln-dried lumber with an
average moisture content range of 6% to 11% for interior
work. Maintain temperature and relative humidity during
fabrication, storage and finishing opera= tions so that
moisture content values for woodwork at time of
installation do not exceed the above range.
B. Replacement Wood: Match species, grade, grain pattern,
and other special characteristics of woodwork.
C. Provide wood blocking, anchorages and fasteners for
a. Select material, type, size and finish
requi= red for each use and as recommended by
b. For metal frami= ng supports, provide screws as
recom= mended by metal framing manufacturer.
2. Nails: Select material, type, size and finish
required for each use and as recommended by RHPO.
3. Anchors: Select material, type, size and finish
required by each substrate for secure anchorage.
Provide nonferrous metal or hot-dip galvanized
anchors and inserts on inside face of exterior
walls and elsewhere as required for corrosion
resistance. Provide toothed steel or lead
expansion bolt devices for drilled-in-place
anchors. Furnish inserts and anchors, as required,
to be set into concrete or masonry work for
subsequent woodwork ancho= rage.
D. Fire-Retardant Materials:
1. Fire-retardant treated lumber shall be lumber and
plywood with fire-retarda= nt chemicals to comply
with ASTM C20 and C27, respectively; provide
materials which are press= ure impregnated with fire-
retardant chemicals and comply with the following
a. Fire-Retardant Chemicals: Use chemicals of
type which do not bleed through or otherwise
adver= sely affect finishes. Do not use
color= ants in solution to distinguish treated
lumber from untreated lumber.
1) Low Hygroscopic Type: Halogen and
sulfate-free solution intended for
interior applications not exposed to
relative humidity more than 95%; with
treated material having an equilibrium
moisture content of not over 28% per ASTM
D3201 at 92 =F1 2% relative humidity.
b. Available Produ= cts: Subject to compliance
with requirements, products which may be
incor= porated in the work include, but are not
limit= ed to, the following:
1) "Dricon" (Koppers Co., Inc.).
2) "Flameproof LHC" (Osmose Wood Preserving
Co. of America, Inc.).
3) "Protex" (Hoover Universal, Wood
2. Fire Performance Characteristi= cs: Provide
materials which are ident= ical to those tested per
ASTM methods and are marked and listed for fire
performance characteristi= cs by Underwriters
Laboratories, Inc. or other testing and inspecting
agency acceptable to authorities having
jurisdiction, and comply with the following
a. Mill lumber after treatment, within limits set
for wood removal that does not affect listed
fire performance characteristics, using a
woodw= orking plant certified by testing and
inspe= ction agency.
b. Marking: = Identify treated lumber with
separ= able paper classification marking of
inspe= cting and testing agency, unless
other= wise indicated.
c. Surface Burning Characteristics: Not
excee= ding values shown below, tested per ASTM
E84 for 30 minutes with no evidence of
signi= ficant combustion.
1. Flame Spread: 25.
2. Smoke Developed: 50.
d. Kiln-dry woodwo= rk after treatment to levels
requi= red for non-fire-retardant woodwork
mater= ials. Maintain moisture content required
by kiln drying, before and after treatment.
e. Discard treated lumber that does not comply
with requirements of referenced woodworking
stand= ard. Do not use twisted, warped, bowed,
disco= lored, or otherwise damaged or defective
A. Wood Moisture Content: Comply with requireme= nts of
referenced quality standard for moisture content of
lumber in relation to relative humidity conditions
existing during time of fabrication and in installation
B. Fabricate woodwork to dimensions, profiles, and details
provided and approved by RHPO.
C. Complete fabrication, including assembly, finishing and
hardware application, before shipment to project site to
maximum extent possible. Disassemb= le components only as
necessary for shipment and installation. Where necessary
for fitting at site, provide ample allow= ance for
scribing, trimming, and fitting.
D. Wood Surrounds and Trim: Fabricate to profil= es required
in single lengths for jamb and head conditions.
Provisions for securing through face of trim shall
include plugs to match surface.
E. Factory-cut openings, to maximum extent possible, to
receive hardware, appliances, plumbing fixtures,
electrical work, and similar items. Locate openings
accurately and use templates or roughing= -in diagrams to
produce accurately sized and shaped openings. Smooth
edges of cutouts and, where located in countertops and
similar exposures, seal edges of cutouts with a water-resistant coating.
F. Measurements: Before proceeding with fabrica= tion of
woodwork required to be fitted to other construction,
obtain field measurements and verify dimensions and shop
drawing details as required for accurate fit.
1. Where the sequence of measuring substrates before
fabrication would delay the project, continue with
fabrication (without field measurements) and
provide ample borders and edges to allow for
subsequent scribing and trimming of woodwork for
G. Preservative Treatment by Non-Pressure Method: Comply
with requirements of referenced woodwork= ing standard for
nonpressure treatment of woodwork with nonaqueous water
repellent solution, except as indicated. Treat units of
woodwork after cutting, machining, sandi= ng, gluing and
assembling has been completed to the greatest extent
possible. Coat surfaces cut after treatment with heavy
brush coating of same preservative.
A. Conserve as much of the original material as possi= ble,
repairing and restoring damaged existing woodwork rather
than replacing it wherever practicable. Use salvaged
material where practical in spaces with some existing
woodwork to remain. If not practic= al, replace all
woodwork with new materials that replica= te the existing
items; maintain RHPO approval.
B. Do a thorough examination of the existing wood condition.
Do any necessary tests on an inconspicuo= us surface to
learn the current condition and appropri= ate steps and
materials necessary for restoration of all existing wood
1. Protect adjacent surfaces with polyethylene covers
during wood removal opera= tions.
2. Protect persons and surrounding surfaces of
building interiors whose wood surfaces are being
restored from damage resulting from wood
B. Surface Preparation:
1. Condition woodwork according to average prevailing
humidity conditions in installation areas before
2. Before installing architectural woodwork, examine
shop-fabricated work for completion and complete
work as required, includi= ng back priming and
removal of packing.
3. Pre-Installation Meeting: Meet at project site
before delivery of archit= ectural woodwork and
review coordination and environmental controls
required for proper insta= llation and ambient
conditioning in areas to receive work. Include in
meeting the contractor; RHPO, contracting officer,
and other owner represent= atives (if any);
installers of architectur= al woodwork, wet work such
as plastering, other finishes, painting, mechanical
work and electrical work; and firms or persons
responsible for continued operation (whether
temporary or permanent) of HVAC system as required
to maintain temperature and humidity conditions.
Proceed with woodwork installation only when
everyone concerned agrees that required ambient
conditions can be maintai= ned.
4. Deliver concrete inserts and similar anchoring
devices to be built into substrates, well ahead of
time substrates are to be built.
3.03 ERECTION, INSTALLATION, APPLICATION
1. Quality Standard: Install woodwork to comply with
AWI Section 1700 for type of woodwork involved.
2. Carefully remove at locations indicated any damaged
or deteriorated woodwork. Unless indicated
otherwise, replace the entire length of the
existing damaged piece to the next butt joint.
3. For partial replacement of existing pieces, use a
neat, well-fitted level cut with grain aligned in
transparent finish wood.<= br>
B. Replacing Deteriorated Material: Install new pieces as
1. Install the work plumb, level, true and straight
with no distortions. Shim as required using
concealed shims. In= stall to a tolerance of 1/8" in
8'-0" for plumb and level; and with 1/16" maximum
offset in flush adjoining surface, 1/8" maximum
offsets in revealed adjoi= ning surfaces.
2. Cut to fit unless specified to be shop-fabricated
or shop-cut to exact size. Where woodwork abuts
other finished work, scribe and cut for accurate
fit. Before making cutouts, drill pilot holes at
3. Standing and Running Trim: Install with minimum
number of joints possible, using full-length pieces
(from maximum length of lumber available) to the
greatest extent possible. Stagger joints in
adjacent and related members. Cope at returns,
miter at corners, and comply with Quality Standards
a. Reuse salvage material as required. Use only
trim that can be reinstalled and refinished to
an acceptable condition consistent with the
exist= ing trim to remain.
b. Where salvage material will not match
exist= ing, remove and replace with new to
repli= cate existing.
4. Anchor woodwork to anchors or blocking built-in or
directly attached to substrates. Secure to
grounds, stripping and blocking with countersunk,
concealed fasteners and blind nailing as required
for a complete installati= on. Except where
prefinished matching fasteners heads are required,
use fine finishing nails for exposed nailing,
countersunk and filled flush with woodwork, and
matching final finish where transparent finish is
5. Finish replacement woodwork to match adjacent
A. Upon completion of this work, all floors, walls and other
adjacent surfaces stained, marred, other= wise damaged by
work under this section shall be cleaned and repaired and
all work and the adjacent areas shall be left in a clean
and perfect condition.
B. All completed work shall be adequately protected from
damage by subsequent building operations and effects of
weather. Protection shall be by methods recommended by
the manufacturer of installed materials and as approved
by the RHPO.
C. Repair damaged and defective woodwork wherever possible
to eliminate defects functionally and visually; where not
possible to repair properly, replace woodwork. Adjust
joinery for uniform appearance.
D. Clean woodwork on exposed and semi-exposed surface= s.
Touch up factory-applied finishes to restore damaged or
A. Protect work of other trades, whether to be restor= ed or
not, against damage by restoration work. Correct any
damage by cleaning, repairing or replaci= ng, as acceptable
to RHPO. At completion of work of other trades, restore
all damaged or defaced surfaces.
B. Provide final protection and maintain conditions in a
manner acceptable to manufacturer and installer, that
ensures that woodwork is being without damage or
deterioration at time of substantial completion.
END OF SECTION