Following the Secretary of the Interior's "Standards for Rehabilitation", Leeds Clark, Inc. has developed a turn-key historic wood window restoration service based on tested and proven methodologies and restoration products. With over 40+ years experience, Leeds Clark, Inc. is confident that no other firm will rate as high in timely completion and within budget, while providing the craftsmanship and expertise expected in historic wood window restoration. Below is the preferred methodology Leeds Clark, Inc. incorporates into its historic wood window restoration projects:

Wood Window Sash

Repair, Prep, Reglazing, & Repainting

Once the wood sashes have completely dried, wood sashes will be moved into shop facility for carpentry and prep work. Perform epoxy and dutchman repairs, replace missing wood window sash components, or mill replacement wood window sashes, where designated, using vertical grain old growth lumber that is called for in the specifications. Wood will be seasoned with a moisture content not to exceed 11% and free of any knots or checks. Match the historic profile of the wood window sashes.

Sand all wood window sashes and seal end grain of wood sash components with epoxy. Apply one coat of specified primer to all wood window sash components, unless the interior of the wood sash is to recieve a stained finish as specified.

Reinstall historic glass in wood window sashes and replace any broken or missing glass with glass that has been specified. Back-glaze wood sashes using a clear siliconized acrylic sealant. Apply push points to seat glass against wood sash and sealant and allow time for curing. Glaze wood window sashes using oil based glazing compound and allow glazing putty time to cure prior to application of specified finish paint. If approved, a beveled wood glazing trim (using same lumber called for in the specifications) will be used in place of glazing compound.

Once wood window sashes have been glazed, apply two coats of specified finish paint to all wood window sash components, unless the interior of the wood window sash is to receive a stained finish.

Once all wood window sashes are completely restored, transport wood window sashes back to jobsite for installation into restored wood jambs.

Install restored wood window sashes into restored wood window jambs. It will have been determined prior to installation as to whether the wood sashes are to be fixed in a closed position, fully double-hung, or have a fixed upper wood sash and operable lower wood sash. If the operable wood sashes are to recieve weatherstripping, it will be installed at the same time of wood sash installation. Leeds Clark, Inc. encourages the use of zinc rib strip weatherstripping for the wood jambs and sides of wood sashes, and a bulb weatherstripping for the meeting rails of the wood sashes. 

Install salvaged and/or new wood window sash lifts and wood window sash locks.

Clean the interior and exterior window glass before the acceptance of the architect/owner.

Complete punch items submitted by architect/owner.

Pulling of Wood Sashes from Wood Jambs & Covering of Window Openings with Plywood

​Please send all wood window restoration inquires to

Transport wood window sashes to Leeds Clark, Inc.'s shop facility for chemical dipping in neutral PH stripper for the removal of paint and glazing compounds in a controlled environment. As of April 22, 2010, a new law governing renovations that contain lead paint became effective. Aimed at protecting against lead-based paint hazards, the EPA’s new rule applies anytime a lead paint surface is disturbed by renovation or painting projects, including repairs, maintenance, electrical, plumbing, carpentry, demolition, and window and door restoration/replacement. The rule also requires renovation firms to be certified by the EPA, and that they assign at least one EPA Certified Renovator to the job to ensure that lead-safe work practice standards are observed. Leeds Clark, Inc. is an "EPA Certified Firm", and both Tom & Chris Clark are "EPA Certified Renovators". Go to for additional information about the new EPA rule and other Lead Programs. Leeds Clark is not a licensed or insured asbestos abatement contractor.

Once the wood sashes have been chemically dipped in neutral PH stripper, the sashes are then moved to an overflow table where the remainder of paint and glazing compounds will be removed from wood sashes. Historic glass will be carefully removed from wood sashes then cleaned and stored away for re-installation in restored wood sashes. Using a gong brush, water will be applied to wood sashes and will be scrubbed clean and neutralized. The wood sashes will then be set out in sun to fully dry for 48 to 72 hours. 

Wood Window Restoration

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Chemical Stripping of Wood Window Sashes

Remove brick molding from outside perimeter of wood window jamb and stamp according to window number and elevation. Chemically strip paint from brick molding at an on-site staging area or off-site at Leeds Clark Inc.'s shop facilities. Remove any caulking or paint from perimeter masonry. Remove parting stop from existing wood window jambs; parting stop will be double-wrapped in poly plastic prior to disposal if it contains lead based paint.

Strip paint from wood window jambs (on-site) using neutral PH based chemical paint stripper. Care will be taken to mask and contain all removed materials for proper disposal. Leeds Clark Inc. is an "EPA Certified Firm", and both Tom & Chris Clark are "EPA Certified Renovators". Visit for additional information about the new EPA rule and other Lead Programs. Leeds Clark is not a licensed or insured asbestos abatement contractor.

Replace wood window jamb components where wood rot or structural stability is in question using old growth lumber that matches in species and graining. Specified wood will be seasoned with a moisture content not to exceed 11% and free of any knots and checks. All replacement wood window jamb components will be primed, back primed, and the end-grain sealed with epoxy prior to installation.

Epoxy all checks and voids on wood window jamb where minor defects or surface deterioration exists such as sills, stool, and lower jamb areas where joinery connects to sill. Prep and sand all wood window jamb components prior to painting.

Reinstall salvaged brick molding or replicated brick molding . Caulk all wood to wood joints using a siliconized acrylic latex sealant and all exterior surround joints of brick molding and sill to masonry using a one-part urethane sealant.

Prime all wood window jamb components, stools, and aprons with approved latex wood primer and apply two finish coats of paint as specified.

Clean, restore, and install salvaged window hardware including rope/chain, pulleys, and weights. Provide new window hardware where missing, matching the original per the specifications.

Leeds Clark, Inc. completely understands no two wood window restoration projects are the same. Tom Clark believes inspection of the historic wood windows and its overall condition is vital in developing a historic window restoration plan. Condition assessment of the historic wood windows helps the architect/owner establish needs, offer realistic solutions and specifications, then develop a plan and budget to determine feasibility of the proposed project.

Wood Window Jamb

Chemically Strip, Repair, Prep, & Repainting

Pull the wood window sashes from the wood window jambs and number according to the window opening on the floor plan. Window number and elevation will be stamped onto each wood window sash to prevent mix-up of wood sashes with corresponding wood jambs. The ropes/chain that have been removed from side of wood sash will be secured to pulley so that rope/chain and window weights are secure. Once the wood sashes have been pulled and stamped, the wood sashes will be transported to Leeds Clark Inc.'s shop facilities to be chemically dipped, repaired, prepped, glazed, and repainted.

Cut and install OSB plywood to cover the wood window openings during wood window restoration work. Plywood will be installed from the interior to butt against outside stop of upper wood sash track and secured to wood jamb using 1 ¼" drywall screws. Plywood will be cut into 60/40 lengths allowing upper piece to overlap lower piece to the exterior; this prevents water infiltration at the joint line. Since plywood is located at the outer portion of the wood jamb, rain water will drain to outer portion of wood sill and not penetrate the interior of the building. This type of plywood installation also allows for daily removal and re-securing during wood window jamb restoration, prep, and repainting. The lower section of plywood can be removed for natural light and air ventilation at any time. If the plywood is to much of an eyesore, it can be painted to match wood jamb and window trim color 

Wood Window Sash Installation

into Wood Window Jamb