Historic wood windows are an impor-tant character-defining feature of mostold buildings. The profiles created by thedifferent components of a historic win-dow create shadow, depth, interest andcomplexity that modern windows usu-ally cannot replicate. It’s often arguedthat historic windows must be replacedbecause of the need for routine mainte-nance or because it’s assumed that theyare not energy efficient. Many studieshave shown that a properly weatherizedrepaired window is at least as energy effi-cient as a modern replacement window,

particularly if a compatible storm win-dow is added. Original windows thathave lasted for decades will, if kept ingood repair, last for many more decades.Most modern replacement windowscannot be repaired and are often de-scribed as “maintenance-free” becausethey cannot be maintained and must bereplaced after only a few years of use.

Before replacing wood windows andstarting a cycle of window replacement,consider investing in your existing win-dows and helping them last for manymore decades. Historic windows also

FastFacts have embodied energy (the materials andenergy required in the original manufac-ture) that is conserved when the window ismaintained and repaired for continued use.The “greenest” window is one that alreadyexists.

Wood window repair is labor intensivebut uncomplicated. Routine maintenancewill eliminate much of the need for majorrepairs. If you hire someone to repair thewindows, it’s a good idea to learn the basicsof window repair so that you will choosethe right person for the job. Also, be awareof the dangers of lead paint. Many historicwindows have been painted with lead paintand your personal safety and the environ-ment should be considered when remov-ing lead paint. Be careful in handling heavywindow sash, sash weights and glass.

Study your windows and determine ex-actly what is wrong with them. Has thepaint failed? Is the glazing putty severelycracked or missing? Is any of the glass bro-ken or missing? Is the window painted ornailed shut? Is the window not functioningproperly because the sash cords have bro-ken? Are any of the wood components softor splintered?

When parts of the window are severelydeteriorated or beyond repair it may be nec-essary to stabilize or replace these compo-nents. Usually, a carpenter or woodworkeris required to replace parts of the windowbut stabilization can be accomplished rela-tively easily by the do-it-yourselfer. Woodthat is deteriorated can be strengthened andstabilized with an epoxy consolidant thatsaturates the porous decayed wood andthen hardens. The surface of the consoli-dated wood can then be filled or built upwith an epoxy patching compound andsanded smooth.

about Repairing Wood Windows

byScott A. McIntosh

Ohio Historic Preservation Office • 800 E. 17th Avenue • Columbus, OH 43211-2474 • 614-298-2000 Visit us at www.ohiohsitory.org/resource/histrpes/

The Ohio Historic PreservationOffice receives federal assistance from the U.S. Department of the Interior’s Historic Preservation Fund. Under Title VI of the Civil Rights Act of 1964 and Section 504 of the Rehabilitation Act of 1973, the U.S. Department of theInterior prohibits discrimination on the basis of race, color, national origin, or handicap in its federally assisted programs. If you believe that you have been discriminated against , or for further information, write: Office of Equal Opportunity, U.S. Department of theInterior, 1859 C Street, N.W., Washington, D. C. 20240.

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The “greenest”window is one that

already exists.

Some basic tools and supplies to ac-complish this job of window repair in-clude a paint zipper (to free the sashesand stops from the frame), utility knife,screwdriver, small pry bar, infrared heatgun, paint scrapers, glazing putty, puttyknife, caulk, linseed oil, sandpaper, tackcloths, hammer, weather stripping, vac-uum cleaner, mask, primer and paint.

Depending on the type and conditionof the windows, the usual steps involvedin simplified form are:

1. After removing the sash locks andother hardware, carefully removethe interior molding (if present), theinterior and parting stops and theaccess panels for the weights (smalldoors that are typically screwed inplace in the jamb).

2. Take the sashes out of the windowframe after removing the sashcords to release the weights. Cleanany debris out of the weight pock-ets.

3. Carefully use your heat gun orother method and remove the paintfrom the jambs and interior stops,then remove the paint, glazingputty and glass from the sashes,taking care not to break the glass.Be sure to mark the glass for correctreinstallation.

4. Make any repairs to the sashes andframes and sand as needed.

5. Prime all sashes, jambs, interiorstops and parting stops.

6. To seal out air around movablesash, install rubber weather strip-ping on the top rail, bottom rail andmeeting rail.

7. Apply a small bead of caulk on theinterior of the stile, rail and/ormuntin where the glass will rest, re-install the original glass on top ofthe caulk, insert the glazing points,apply the glazing putty and bevelit.

8. After a “skin” has formed on theglazing putty, apply two coats of

paint to the sashes, jambs andstops. The first coat should dryovernight before applying the sec-ond coat.

9. Carefully clean any excess caulk,glazing putty and paint off of glassusing a razor blade.

10. Thread new sash cords from thetop, tie them securely to theweights and attach them to thesashes, being sure that the cords arethe correct length for proper opera-tion of the sash. Reinstall the accesspanel.

11. Reinstall the repaired upper sash,parting stop, lower sash and inte-rior stop, in that order.

12. Reinstall the sash locks and hard-ware.

There are many resources available on-line and elsewhere to help you repairyour historic wooden windows. Preser-vation Brief 9: The Repair of Historic WoodenWindows, published by the National ParkService, provides a detailed explanationof wooden window repair. You can findthis brief and other information atwww.nps.gov/history/hps/tps/. For helpin finding additional resources or if youhave questions, please contact the staff inthe Technical Preservation Services de-partment of the Ohio Historic Preserva-tion Office at 614/298-2000 orohpo@ohiohistory.org.

Ohio Historic Preservation Office • 800 E. 17th Avenue • Columbus, OH 43211-2474

614-298-2000 • Visit us at www.ohiohistory.org/resource/histpres/FastFacts

Scott McIntosh is a Technical PreservationServices Manager at the Ohio Historic Preser-vation Office. He holds degrees in history andhistoric preservation from the University ofKentucky.

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