Window Sash, Sill and Frame Repair in Madison, WI

What to describe in the quote form or when you call

Tell the company what you see, in the form's details or on the call. These are the things worth describing, on the outside first, then the inside. Only an inspection can say what they mean.

• Paint that is cracked, peeling or bubbling, especially along the sill and at the bottom corners.
• Wood that feels soft, spongy or crumbly, or that breaks away in pieces.
• A sash that sticks, hangs crooked or will not close tight.
• A sash that is painted shut.
• Gaps or drafts near the frame.
• Water stains on the wall or trim under the window.

Is the frame the problem, or the sash or sill?

Ask the company to name which part is damaged: the sash, the frame or the sill, and how it checked. A quote that lists each part separately is easier to compare. If the glass is the only broken part, see window glass replacement. If the window will not stay open, see the balance and hardware repair page.

What causes window rot: water at the sill, failed putty and paint, condensation

The National Park Service's Preservation Brief 9 is general technical guidance on historic wood windows, written in 1981 for the whole country. It is not a Madison rule. It says many things can wear out a window, but moisture is the primary contributing factor in wooden window decay (NPS Preservation Brief 9). The places water gets in and stays:

• Sill and joints. Rain outside and condensation inside run down the window. They collect where the flow is blocked: the sill, the joints between sill and jamb, the corners of the bottom rails and the muntin joints. Years of opening and seasonal temperature change loosen these joints. The end grain then soaks up water.
• A sill that does not shed water. NPS says the sill should slope away from the building, and that a drip line cut along its underside helps run-off, especially on a flat-bottomed sill. Anything that lets water puddle on the sill must be corrected.
• Failed glazing putty. Cracked, loose or missing putty lets water saturate the wood, especially at the joints. The putty on the inside of the pane keeps condensation from running down into the joinery.
• Failed paint. Blistering, cracking, flaking and peeling paint usually mark where water got in. NPS adds that wood is frequently sound beneath unsightly paint, so peeling paint alone does not mean the window is beyond repair.
• Gaps at the frame edge. NPS says to check for water entering around the edges of the frame and to caulk the joints or seams. Flashing is covered in the leaks section below.

NPS describes a simple soundness test: wet the wood and jab an awl or ice pick in at an angle. Sound wood lifts in long fibrous splinters; decayed wood comes up in short, irregular pieces. Pushed straight in, the probe can find a rotted core under a sound-looking skin, which NPS calls especially useful on sills, where the underside is hard to see. NPS also says that before any repair, every source of moisture should be found and eliminated and existing decay fungi destroyed. Many fungicides and wood preservatives are toxic, so follow the label. When you compare quotes, ask what each one does about the water, not only about the wood. Madison's climate figures are in the climate section below.

Repair options: epoxy consolidation and filler, splicing in new wood, parts replacement, new sash in the old frame

NPS Preservation Brief 9 (1981, national guidance) sorts wood window repair into three classes: routine maintenance, structural stabilization, and parts replacement. Each class takes more skill, costs more and takes longer than the one before. NPS says most windows should not need the heaviest class. The ones that do are usually in buildings left without maintenance for years. Ask the company which class it proposes for each part of your window (frame, sill, sash and trim), and ask for that in the quote. No source we read gives steps for sill replacement or for replacing exterior trim or brick mold, so ask the company to explain those in its quote.

Epoxy consolidation and filler

(1981) NPS says decayed, porous wood can be strengthened with a semi-rigid epoxy that soaks in and hardens. The surface is then filled with an epoxy patching compound, sanded and painted. The same compound can build up missing sections or decayed ends, and hand molds copied from a sound section can reproduce a profile. NPS calls epoxy comparatively expensive but among the most durable, long-lasting materials for wood repair. Its other stabilization method has several steps. Dry the wood and treat the decayed area with fungicide. Apply two or three coats of boiled linseed oil a day apart. Fill cracks and holes with putty, and paint once the putty forms a skin. A weathered sill can also be built up in layers with wood putty or a mix of sawdust and resorcinol glue, then sanded, primed and painted. NPS says any patched flat surface should keep a slight slope so water runs off. Ask which of these the company proposes, which product it will use and what happens if the wood behind the patch is worse than it looks.

Cutting out and splicing in new wood

For parts too far gone to stabilize, NPS says new matching pieces can replace them, or new wood can be spliced into the existing member. The sash or the affected frame parts come out, and a carpenter or a woodworking mill reproduces the damaged or missing parts. NPS says most millwork firms can duplicate muntins, bottom rails or sills. It also warns that some mills avoid old sash. Nails can damage their knives, and some lack the cutter for a muntin profile. It may take some shopping around. Ask whether splicing is proposed for any part, which wood will be used, how the new piece is joined and sealed, and whether the rest of the original window stays.

Window sill replacement

NPS covers sill repair (the epoxy and built-up methods above) and notes that mills can duplicate sills. The National Trust lists the sill and stool among the parts of a traditional window that can be replaced in kind. We found no source with replacement steps or a sill-only price. Ask whether the company recommends window sill repair or window sill replacement, what in its inspection led to that, and for the sill as its own line in the quote. The leaks and flashing section below explains sill flashing as DOE describes it for new installation. Ask whether any flashing work is in the quote.

Repairing the frame in place

NPS advises repairing a frame in place wherever possible, using stabilization and splicing. It warns that taking a frame out can be complicated by its connection to the surrounding structure, especially masonry walls, and may even mean dismantling part of the wall. If a company proposes removing a frame, ask why it cannot be repaired where it sits.

Sash repair and rebuilding so it runs smoothly and fits

(1981) For wood sash repair, NPS describes taking the sash out and repairing it at a work area, with the opening covered with polyethylene or plywood while it is gone. If extensive parts replacement makes repair too costly, NPS says it may be more practical to buy new wooden sash that fit the existing frames, either custom reproductions or sash of similar appearance (sash replacement). Ask whether the company would repair the sash, rebuild it or make or order a new one, and what the sash must do when the job ends: close tight, run smoothly and sit square in the frame.

Exterior trim, casing and brick mold

Window trim repair, window trim replacement, exterior window trim repair and window casing repair all deal with the trim around the opening. We found no source for a repair method or a price for exterior trim or brick mold. Ask whether trim, casing or brick mold is in your quote, whether it is repaired or replaced, and how it is priced.

Leaks and flashing around the frame

The U.S. Department of Energy's building-science page says windows and doors are vulnerable points where moisture and air can get in, the sill especially. It describes full sill flashing as a back dam (a wood strip or beveled siding along the inside edge of the opening) plus self-adhesive flashing membrane pressed tightly into the corners so it does not tear. Non-elastic membrane must be cut and patched at the corners, and rigid two-piece pan flashing has a built-in back dam that must be protected from breakage (U.S. DOE). The page covers new installation, not repair of an installed window. For window leak repair, ask the company to find where water is entering before it quotes, and to say whether the fix is resealing, caulking or flashing work, and what has to come off to do it. The leak and flashing cost ranges are in the table below.

Sticking, painted-shut and warped sashes: freeing and adjusting

Renewal by Andersen says sticky sashes are often caused by paint buildup, swelling or minor misalignment when the frame is not warped or damaged. It says worn weatherstripping can be replaced and a hardware swap is usually straightforward when the frame is solid, and that repeated failures in one window often point to a larger problem. It also says visible frame rot points to replacement, which is a view from a company that sells replacements. NPS notes that old windows often carry many layers of paint, and that removing excess or peeling paint helps the window work again. NPS Brief 9 was written in 1981 and does not mention lead paint, so follow the lead-safe rules below, not its stripping tips. We found no source for a step-by-step painted-shut method, so ask the company how it would free the sash and what it would check afterward. If the sash moves but will not stay up, see the balance and hardware repair page.

Weatherproofing after repair: paint, glazing putty, caulk where appropriate, weatherstripping

(1981) Ask the quote to say what is included at the end of the job: paint, glazing putty, caulk where appropriate and weatherstripping. NPS says glazing compound goes only on wood brushed with linseed oil and primed with an oil-based primer or paint. The putty can be painted once a skin forms, usually in 2 or 3 days, and the paint should lap slightly onto the glass to seal. NPS also says old felt weatherstripping is not likely to perform well, and that felt can hold moisture, especially on the bottom rail. It lists rolled vinyl, metal and plastic spring strips as alternatives. For older homes with original windows, see historic wood window restoration.

Vinyl, aluminum and fiberglass frames: what can be repaired and what can't

The National Trust for Historic Preservation says traditional windows are built from parts (rails, stiles, muntins, stops, sill, stool, jamb) that can each be repaired or replaced in kind. It says vinyl, aluminum, fiberglass and composite windows are made as a single unit whose components generally cannot be repaired, so one failed part usually means replacing the unit (National Trust, Save the Places). Renewal by Andersen, a manufacturer that sells replacement windows, says high-quality vinyl can last around 20 to 40 years but may wear out sooner in extreme temperature swings, and wood frames 15 to 30 years with regular upkeep (Renewal by Andersen). Both are national sources, not Madison findings. Neither covers aluminum or fiberglass repair procedures, and we found no source for them, so tell the company what your frame is made of and ask whether it repairs that material.

Repair vs replace: cost, matching the house, how long a repaired window lasts

This is the question behind "should I repair or replace my windows?" Weigh cost, matching the house, and how long a repaired window lasts. The table lists questions to put to the company, not rules; only the Madison historic row is a city rule. Ask for a replacement quote next to the repair quote, so you can compare the two totals.

NPS Preservation Brief 9 (1981, historic windows) recommends keeping and repairing original windows whenever possible. It says repair is more practical than most people realize. It says repaired, properly maintained wood windows get greatly extended service lives. It adds that repair can stay cost effective even when some parts are replaced, if the share replaced per window is low. How long your repair lasts depends on the wood, the cause and the finish, so ask the company how long it expects the repair to hold and what that depends on.

Cost by damage level: minor frame repair vs rotted frame, sash cords, flashing

The figures below come from two national cost guides. They are not Madison prices and carry no local adjustment. A written quote from a local company is the only real Madison number. Cost by damage level runs from minor frame repair to a rotted frame, with flashing in its own row. No sash cord price is listed; ask for it as a separate line.

This Old House says its figures use cost data from Angi. The figures used here do not include prices for window trim repair, window casing repair, window sash replacement, window sill replacement, sill-only repair or full restoration, so none are listed. Ask each company to price those parts as separate lines after it inspects the wood.

What moves the price

• The type of damage. The table above prices minor frame repair, a rotted frame, a leak, flashing and an air leak in separate rows.
• What the quote covers. Ask which parts are in it: sill, sash, trim, brick mold, glass and finish.

How long a repair takes: on site vs in the shop

Time depends on the company and the job. NPS says sash are taken out and repaired at a work area, while frames are repaired in place where possible. Ask which parts of your job would be done on site and which in a shop, and for how long the openings stay covered. For a sense of the steps only, NPS describes a 1981 example by an unskilled staff member on a window over ninety years old with sound wood: about an hour per sash to remove paint, putty and glass, about an hour to reglaze both sash, and about an hour and a half to weatherstrip, fit new sash cords and reassemble. The whole job took several days because putty, primer and paint need time to cure. That is not a contractor's schedule; ask for start and completion dates in the contract (Wisconsin DATCP).

Madison climate and window wood

The University of Wisconsin State Climatology Office lists 1991 to 2020 normals of 51.8 inches of snow a year and a January normal low of 11.8 F. The same page lists 7,138 heating degree days a year (base 65). Those figures describe a cold, snowy place; they do not tell you how fast any window will rot. Ask the company how the repair and finish are meant to cope with Madison winters.

Pre-1978 homes: lead-safe work rules for scraping and sanding painted window parts

Lead may still be present in paint in homes built before 1978 (Wisconsin DHS). The Wisconsin Department of Health Services (DHS) says its lead-safe renovation rule applies to homes and child care centers built before 1978. DHS says both the company and the individuals doing the work need certification. Its FAQ says paid work counts as a renovation when it disturbs more than 6 square feet of painted surface in a room. The exterior trigger is more than 20 square feet. Window replacement is covered whatever the area, even when the old windows are vinyl. Any company that offers renovation work must be a certified lead company, and each project needs an assigned certified renovator. DHS lists these as banned practices: methylene chloride paint strippers, dry sweeping, hydro-blasting unless fully contained, and collecting paint chips for lab analysis. Interior cleanup needs a HEPA vacuum. DHS says owners working on their own home are generally outside the rule if only they and immediate family live there, no child with a high blood lead level lives there and no part is rented. Rental property is covered.

The U.S. EPA says replacing a pane of glass or fixing a broken window balancer is not a window replacement, but the job is still covered unless it qualifies as minor repair and maintenance (not more than 6 square feet of painted surface per room). EPA notes that the glazing around older panes is painted, so that paint counts. The DHS FAQ lists 6 and 20 square feet as triggers and lists no minor-repair exemption, while EPA describes one. This page does not resolve the difference. Ask the company which rule it works under and how your job measures up. Public Health Madison and Dane County names homes built before 1978 as the most common source of lead exposure.

Before you sign for a pre-1978 home, DHS suggests these steps:

• Check the DHS certified lead company list, and confirm the worker is individually certified as a Lead-Safe Renovator and works for a certified lead company.
• Ask whether you will receive the EPA Renovate Right pamphlet and sign a confirmation form. DHS says the pamphlet must be given no earlier than 60 days before work starts.
• Ask how the company will set up containment, use lead-safe work practices, clean up and verify the area is safe.
• Keep copies of the certifications, the signed pamphlet form, a summary of the work and the cleaning verification.

Madison permits and historic rules

The City of Madison permit chart lists "Windows & Frames - replace" as needing a permit from Building Inspection. The chart says nothing about repairing a sash, sill or frame. Madison's storm-damage page says a permit is not required for small repairs under $500 in estimated value. The city's online-permit page says like-for-like window replacement in an existing opening can be permitted online. Adding, removing or resizing windows needs plan review. We found no Madison rule that answers whether a sash, sill or frame repair needs a permit. The chart sends glass-only, storefront and historic-district questions to Zoning staff. It lists window replacement under Building Inspection, so ask Building Inspection whether your sash, sill or frame repair needs a permit, and ask the company how it handles permits.

Madison has five local historic districts: First Settlement, Mansion Hill, Marquette Bungalows, Third Lake Ridge and University Heights. The Landmarks Commission must approve exterior changes on locally designated properties, and the city asks owners to apply for the Certificate of Approval before the building permit. The city's published standards for the districts say that maintenance work alone needs no Certificate of Approval, that original decorative windows shall be repaired and retained, and that original windows may be replaced only when too deteriorated or hazardous to repair. They also say the wood or metal of the jamb, sash and trim shall be protected, and that deteriorated or broken parts shall be repaired. That standards PDF carries no date, and its wording may predate later changes. If your home is in a district or is a local landmark, confirm with the city's Preservation Planner before work begins.

How to choose a window repair contractor in Madison

Whoever you hire as a window repair contractor, get these in writing before work starts.

• The cause and the method. Where the water got in, and which repair method applies to each part.
• The materials. What wood or filler, how it is finished, and how caulk and flashing are handled.
• The lead-safe status. For a pre-1978 home, the DHS-certified company and individual, as above.
• The contract. DATCP says a written contract should include the company's name and street address, a full description of the job, a detailed materials list, the total price, start and completion dates, and any written promise about the work with its limits.
• The state credential. The City of Madison says contractors on one- and two-family homes must hold a State of Wisconsin license, and suggests checking the state's online lookup. The page does not say which credential covers window glass work or window repair, so ask the company which one it holds.
• The permit plan. Who asks Building Inspection, and what happens if the answer is yes.

Compare at least two quotes line by line, not just by total. Check that each quote says whether priming, flashing and lead-safe steps are included. Under Wisconsin law (Wis. Stat. 423.202), if you sign a contract over $25 at home or away from the company's regular place of business, you have three business days to cancel, and the company must give you a cancellation notice.

Ask whether the estimate is free. When you are ready, see how to reach Madison Window Repair: you send the quote form or call, and we pass your request on.

Window frame repair questions

Can a rotted window frame be repaired?

Only an inspection shows whether a wood window can be repaired or needs replacing. Ask the company to explain what it found, which parts it would repair and, if it recommends replacement, why.

How do I know if the frame is the problem?

Only an inspection can say. Tell the company what you see: soft or crumbling wood, peeling paint, a sash that no longer fits, water marks under the window. Then ask which part is damaged (sash, frame or sill) and how it checked.

How much does it cost to repair a rotted window frame?

National cost guides list rotted frame repair at $250 to $800 per window, and minor frame repair at $75 to $200 (HomeAdvisor, 2026-06-17). The cost to repair a rotted window frame in Madison is set by a written quote after inspection.

Can a vinyl, aluminum or fiberglass window frame be repaired?

The National Trust says these windows are made as a single unit whose components generally cannot be repaired, so one failed part usually means replacing the unit. We found no source on aluminum or fiberglass repair procedures, so ask the company whether it repairs your frame material.

What causes wooden windows to rot, and how do I keep wood from rotting around windows?

NPS Preservation Brief 9 (1981, national guidance) names moisture as the primary cause. Water collects at the sill, the sill-jamb joints, the bottom rail corners and the muntin joints, and it gets in through failed putty and paint and a sill that does not shed water. To keep wood from rotting, NPS says to stop the water first. Only an inspection shows what caused the damage on your window, so ask the company where water got in and what the quote does about it.

How is rotted window wood repaired?

NPS Preservation Brief 9 (1981, national guidance) lists three levels: routine maintenance, stabilization with fungicide, linseed oil and putty or with epoxy consolidant and filler, and parts replacement by splicing in new wood or fitting matching pieces made by a carpenter or mill. Each level costs more and takes longer. The Brief gives no steps for replacing a sill or trim, so ask the company about those.

Should I repair or replace my windows?

Ask the company how much of the wood is sound and whether the cause of the damage can be dealt with, and compare its repair quote with a replacement quote. In a Madison historic district, the city's standards say original decorative windows shall be repaired and retained, and may be replaced only when too deteriorated or hazardous to repair.

How do I free a stuck or painted-shut window?

Ask the company why the sash stuck and how it would free it. Lead may still be present in paint in homes built before 1978 (Wisconsin DHS), so read the lead-safe section above before you scrape or sand anything yourself.

Do I need a lead-safe certified company in a pre-1978 home?

For paid work that disturbs paint in a pre-1978 home, in many cases yes. DHS says both the company and the individuals need certification for covered work, and EPA says window replacement is always covered. You can check the DHS certified list yourself.

Does the lead-safe rule cover a glass or balance repair?

EPA says replacing a pane or fixing a balancer is not a window replacement but is still covered above 6 square feet of painted surface per room. The Wisconsin DHS FAQ lists 6 square feet inside and 20 outside as triggers and lists no minor-repair exemption. Ask the company which rule it works under.

Sources

• National Park Service, Preservation Brief 9: The Repair of Historic Wooden Windows (1981, national guidance)
• HomeAdvisor, window repair cost (page dated 2026-06-17)
• This Old House, window repair cost (page dated 2026-06-23)
• Wisconsin DHS, lead-safe renovation
• Wisconsin DHS, hire a lead-safe contractor
• Wisconsin DHS, lead-safe renovation FAQ
• Renewal by Andersen, when to repair vs replace windows (a replacement-window seller)
• National Trust for Historic Preservation, retrofitting historic windows
• U.S. DOE, fully flashed window and door openings: sill flashing
• U.S. EPA, Renovation, Repair and Painting Program
• U.S. EPA, window repair under the RRP rule
• Public Health Madison and Dane County, lead exposure release (archived 2015)
• Wisconsin State Climatology Office, Madison climate
• City of Madison, permits chart
• City of Madison, storm damage guidance
• City of Madison, online permits for 1- and 2-family homes
• City of Madison, historic preservation
• City of Madison, Historic Districts Standards (undated PDF)
• Wisconsin DATCP, home improvement consumer tips

How to request a window frame repair quote

Send the quote form on this page or call. You pay Madison Window Repair nothing for the request or the call. See how to reach Madison Window Repair.

Call or send the quote form and leave a message. We call you back within one business day and connect you with a local window frame repair company. Call (804) 889-2677.