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Rotten Window Repair
Wood rot in window frames and sills is one of the most common — and most misunderstood — problems facing Long Island homeowners. Many people see soft, crumbling wood around a window and immediately assume the whole window needs to be replaced. In most cases, that's not true and here we explain why.
At Prestige Window Works, we specialize in rotten window repair throughout Nassau County and Suffolk County. Our technicians assess the extent of rot damage on-site, remove only what can't be saved, rebuild the affected area to full structural integrity, and seal it against future moisture intrusion — all without pulling out your existing window.
We've completed over 6,000 window and door repair projects across Long Island. Every rotten window repair comes with a 5-year warranty on workmanship and materials. If you can see soft, dark, or crumbling wood anywhere around your window frames or sills, don't wait. Rot spreads. The longer it's left, the more expensive the repair becomes.
How to Tell If Your Window Has Wood Rot
You don't need to be a contractor to spot early rot. Check your windows for any of these signs — if you see two or more, call us or fill out the form online:
Soft or spongy wood
Take a firm finger or a screwdriver handle and press on the wood around the frame corners and sill. Healthy wood doesn't give. If the wood feels soft, compresses under light pressure, or your fingernail can dent it easily, rot is present.
Discoloration
By discoloration are meant dark brown, grey, or black patches Healthy exterior wood paint is uniform. Dark staining at the base of frames, across sills, or at joints almost always indicates moisture penetration and early fungal activity underneath.
Paint that peels or bubbles
Paint bubbling on the exterior surface of a window frame (not the interior) means moisture is coming from inside the wood and pushing the paint off. The wood beneath is wet and may already be rotting.
Visible cracks along the grain
Wood rot often follows the grain of the wood, creating a cracked, cuboid pattern sometimes called "cubical rot" or "brown rot." If you see this pattern anywhere on your window frames, the structural wood fibers have already begun to break down.
Gaps opening up at frame joints
When wood rots, it shrinks. Gaps that appear at the corners of window frames — where the vertical stiles meet the horizontal rails — mean the wood has lost mass. Air and water are now getting directly inside.
Drafts or condensation
These are late-stage symptoms. If you're feeling cold air through a closed wood window or seeing persistent condensation on the inside of the glass, moisture has already penetrated deep into the frame system. This needs immediate attention.
Our Rotten Window Repair Process
We do not use generic fillers or cosmetic patches that hide rot without actually curing it. Here is the exact process we use on every job:
Step 1 — Free On-Site Assessment
Step 2 — Remove All Compromised Wood
Step 3 — Apply Borate Treatment
Step 4 — Rebuild with Epoxy or Dutchman Repair
Step 5 — Prime, Seal, and Paint
Step 6 — Identify and Fix the Moisture Source
Step 1 — Free On-Site Assessment
Step 2 — Remove All Compromised Wood
Step 3 — Apply Borate Treatment
Step 4 — Rebuild with Epoxy or Dutchman Repair
Step 5 — Prime, Seal, and Paint
Step 6 — Identify and Fix the Moisture Source
Rotten Window Repair vs. Full Window Replacement
This is the most common question we get on rot repair calls. The answer depends on how far the rot has progressed — but repair is the right choice in the majority of cases.
Choose repair when:
Consider replacement when:
We will tell you honestly which situation you're in. If replacement makes more sense, we'll say so — we have no interest in selling a repair that won't hold.
We repair rotted frames, sills, and surrounds on wood windows and wood-clad windows from every major manufacturer: Andersen, Marvin, Pella, Weather Shield, Lincoln and other wood-framed and wood-clad window brands.
Choose repair when:
- Rot affects less than 50–60% of the frame structure
- The sash is still sound even if the frame has damage
- The windows are original to the house (pre-1980 old-growth timber that can't be replicated)
- The property is in a historic district — many areas in Garden City, Oyster Bay, Sag Harbor, and Cold Spring Harbor restrict or prohibit window replacement
- Budget is a factor — repair typically costs $200–$700 per window vs. $800–$2,500 for full replacement
Consider replacement when:
- More than 60% of the structural frame is compromised
- The rot has spread into the rough opening, affecting the structural framing of the wall
- The window is a relatively modern replacement with no historical significance
- Multiple windows need work and replacement economics make more sense at scale.
We will tell you honestly which situation you're in. If replacement makes more sense, we'll say so — we have no interest in selling a repair that won't hold.
We repair rotted frames, sills, and surrounds on wood windows and wood-clad windows from every major manufacturer: Andersen, Marvin, Pella, Weather Shield, Lincoln and other wood-framed and wood-clad window brands.
What We Repair
Rotted Window Sills
The sill is the most commonly rotted part of any window. It sits horizontally, collects rain, and is the first place water sits after a storm. We rebuild rotted sills using epoxy or replacement timber and regrade the slope to ensure water drains away from the frame rather than pooling.
Rotted Window Frames
The vertical and horizontal frame members (stiles, rails, and jambs) rot from the outside in, typically starting at end grain or paint failure points. We repair individual sections without replacing the entire frame in the majority of cases.
Rotted Sash
The sash — the part that holds the glass — can rot at the corners and bottom rail, particularly in double-hung windows and casement windows. We repair or rebuild rotted sash sections while preserving your original glass where it's undamaged.
Rotted Window Surrounds and Exterior Trim
The decorative trim around windows is often the first part to show rot because it's exposed on all sides. We repair or replace rotted exterior trim and ensure the new sections are properly integrated and sealed.
Rotted Door Frames
The same rot problems that affect windows affect exterior door frames — especially at the bottom where the frame meets the threshold. If you have rot around a door as well as a window, we can address both in a single visit. See our door adjustment service for related door repair work.
The sill is the most commonly rotted part of any window. It sits horizontally, collects rain, and is the first place water sits after a storm. We rebuild rotted sills using epoxy or replacement timber and regrade the slope to ensure water drains away from the frame rather than pooling.
Rotted Window Frames
The vertical and horizontal frame members (stiles, rails, and jambs) rot from the outside in, typically starting at end grain or paint failure points. We repair individual sections without replacing the entire frame in the majority of cases.
Rotted Sash
The sash — the part that holds the glass — can rot at the corners and bottom rail, particularly in double-hung windows and casement windows. We repair or rebuild rotted sash sections while preserving your original glass where it's undamaged.
Rotted Window Surrounds and Exterior Trim
The decorative trim around windows is often the first part to show rot because it's exposed on all sides. We repair or replace rotted exterior trim and ensure the new sections are properly integrated and sealed.
Rotted Door Frames
The same rot problems that affect windows affect exterior door frames — especially at the bottom where the frame meets the threshold. If you have rot around a door as well as a window, we can address both in a single visit. See our door adjustment service for related door repair work.
Rotten Window Repair Across Nassau and Suffolk County
We provide rotten window repair throughout Long Island, NY from our two service offices:
Our Manhasset office serves all of Nassau County, including: Great Neck · Port Washington · Roslyn · Garden City · Hempstead · Levittown · Massapequa · Oyster Bay · Hicksville · Westbury · Old Westbury · Manhasset
Our Hauppauge office serves all of Suffolk County, including: Huntington · Smithtown · Commack · Bay Shore · Babylon · Patchogue · Riverhead · East Hampton · Sag Harbor · Cold Spring Harbor · Stony Brook · Ronkonkoma
Don't see your town? We serve all of Long Island. Call 516-908-8005 and we'll confirm coverage for your area.
Our Manhasset office serves all of Nassau County, including: Great Neck · Port Washington · Roslyn · Garden City · Hempstead · Levittown · Massapequa · Oyster Bay · Hicksville · Westbury · Old Westbury · Manhasset
Our Hauppauge office serves all of Suffolk County, including: Huntington · Smithtown · Commack · Bay Shore · Babylon · Patchogue · Riverhead · East Hampton · Sag Harbor · Cold Spring Harbor · Stony Brook · Ronkonkoma
Don't see your town? We serve all of Long Island. Call 516-908-8005 and we'll confirm coverage for your area.
THE MOST POPULAR QUESTIONS
How much does rotten window repair cost in Long Island?
Rotten window repair costs in Long Island typically range from $250–$800 per window, depending on the extent of the rot, window type, and material (especially wood frames/sills).
Minor rot or sill repairs often fall on the lower end ($250–$500), while extensive frame damage or full section replacement can push toward $600–$800 or more. Wood windows are most prone to rot due to moisture, and early intervention helps avoid pricier full replacements.
Can rotted wood actually be repaired, or does the window have to be replaced?
In most cases, yes — rotted wood can be fully repaired to structural integrity using epoxy consolidants and filler or Dutchman carpentry. The key is catching it before more than 60% of the structural frame is compromised. Even significant rot damage is repairable in the majority of cases we see across Nassau and Suffolk County.
How long does a rotten window repair last?
A properly executed rot repair — meaning all compromised wood was removed, borate treatment was applied, the void was rebuilt with quality epoxy or timber, and the repair was primed, sealed, and painted — should last 15–25 years or longer. Our repairs come with a 5-year warranty on workmanship. Repairs that fail early are almost always the result of skipping the borate treatment step or leaving rot behind. We do neither.
Will the repaired area look different from the rest of the window?
No. When the job is complete, the repaired area is primed, sealed, and painted to match the surrounding surface. A properly finished epoxy or timber repair is visually indistinguishable from the original wood.
How quickly does rot spread if I leave it?
Faster than most people expect. In Long Island's humid summers, active wood rot can double in size in a single season. A small soft spot at a sill corner in spring can be a structurally compromised 6-inch section by autumn. The longer you wait, the more expensive the repair — and at some point, repair is no longer an option. If you've noticed anything soft or discolored around your windows, book an inspection now.
Do you repair rot in historic homes?
Yes. We have extensive experience with historic properties throughout Long Island, including homes in designated historic districts where original windows must be preserved. Our historic window and door restoration service is specifically designed for these situations. We work with homeowners in Garden City, Oyster Bay, Sag Harbor, the Hamptons, and other areas with historic preservation requirements.
Do you repair rotted door frames as well as windows?
Yes. Wood rot affects door frames through exactly the same mechanism as window frames. We repair rotted exterior door frames, sills, and surrounds in the same visit as window rot work. See our wood window and door repair service for full details on door-related work.