Old wood windows give a house real character, but once the putty around the glass cracks and drops out, that charm turns into rattling panes and cold drafts. Reglazing fixes it: you strip out the failed compound and seal the glass back into the sash.
It is one of the most forgiving DIY repairs there is. No trade skills, a handful of cheap tools, and an afternoon per sash are all it takes to weatherproof a window and set it up to last another few decades.
Here is the whole process, start to finish, plus how to tell when reglazing beats buying a new window.
Key Takeaways
- Window glazing is the putty compound that beds the glass into a wood sash and seals out water and wind; reglazing means replacing that failed putty.
- The core steps are strip the old putty, prime the bare wood, set glazier’s points, press in fresh compound, tool a 45-degree bevel, then paint once it skins over.
- A DIY reglaze runs under $50 in materials, since one tub of compound seals many windows, versus roughly $250 to $500 per sash to hire it out.
- Reglaze instead of replace when the wood frame is still solid or the window is historic; a restored wood window can outlast a modern replacement by decades.
What Is Window Glazing?
Window glazing is the glazing compound, a linseed-based putty that beds the glass into a wood sash and seals the gap against weather. The word actually gets used three ways, which is where the confusion starts. Strictly, glazing is the glass pane itself. In DIY terms, though, it almost always means that putty compound.
Glazing also names the act of applying that putty. This guide uses that last sense: how to dig the rock-hard, cracked compound out of an old single-pane sash and pack in fresh putty that holds for years.
Reglazing is simply doing it again on a window that has already lost its original putty. The glass and frame usually stay put; only the failed seal gets replaced.
How to Reglaze a Window Step-by-Step
The glass in an older window sits in a bed of putty that hardens as it ages. After decades of sun and rain, that compound shrinks, cracks, and falls out, which lets water reach the wood and lets heated air leak straight through the joint.
You can reverse all of that in an afternoon per sash. Gather your supplies before you pick up a scraper.
Tools and Materials
- Razor knife.
- Stiff putty scraper.
- Heat gun (or infrared stripper).
- Glazier’s points (they hold the glass).
- Sandpaper (100 to 120 grit).
- Glazing compound (oil-based or latex).
- Oil-based primer.
- Sash brush.
- Lead paint test kit (for older homes).
1. Remove the Sash
You can glaze a window while it hangs in place, but gravity fights you the whole time, so working flat is far easier. Pry off the stops (the thin wood strips that hold the sash in the frame) and lift the sash out.
Lay it on a workbench or a pair of sawhorses. If paint has sealed the stops in place, score the paint line with a razor knife first so you do not splinter the trim.
2. Remove the Old Glazing
Every bit of the old, cracked putty has to come out. Chip it away with a stiff scraper or a dedicated glazing knife.
If the compound is rock-hard, warm it with a heat gun to soften it first. Keep the gun moving so you do not scorch the wood or heat the glass enough to crack it.
Safety Warning
3. Prep and Prime the Frame
With the wood bare, check it for rot. Dig out any soft spots and fill them with two-part wood epoxy, then sand the frame lightly so the surface is smooth and clean.
Do not skip this next part: prime the bare wood with an oil-based primer. Dry wood wicks the oils out of fresh glazing compound and makes it dry brittle and fail early, so the primer seal is what lets the new putty last. Let it dry fully before you glaze.
4. Set the Glass and Points
If you took the glass out to clean it, lay a thin 1/8-inch bead of compound into the sash first and press the pane into it. This “back bedding” keeps the glass off the bare wood and cushions it so it will not rattle or crack.
Then push glazier’s points (small metal triangles) into the wood every 6 to 8 inches, with at least one on each side. These points are what actually hold the glass; the putty is only a weather seal. Press each one flat against the glass.
5. Apply the Glazing Compound
Knead a handful of compound until it warms up and feels like soft dough. Roll it into a rope about as thick as a pencil.
Press the rope firmly into the corner where the glass meets the wood, packing it in a little heavy so no air gaps hide underneath.
6. Smooth the Joint
Hold your putty knife at roughly a 45-degree angle and drag it along the putty in one firm, steady pass to cut a clean, angled bevel.
That slope sheds water off the glass instead of letting it pool. If the bead tears or looks ragged, scrape it out and try again; fresh putty is forgiving. Wipe the excess off the glass and tidy up the corners.
7. Paint the Glazing
Do not paint right away. Oil-based glazing putty cures slowly by oxidation, so it has to “skin over” (firm up on the surface) first. That usually takes about 5 to 7 days, and in cool or humid weather it can stretch to a couple of weeks. The one exception is traditional linseed-oil paint, which can go on immediately.
Once a firm skin forms, brush on a quality exterior paint. Lap the paint about 1/16 inch onto the glass. That thin overlap bridges the putty-to-glass seam and blocks water from creeping in behind the compound.
Cost to Reglaze Windows
Reglazing is cheap next to replacement. Hire a pro and you will pay roughly $250 to $500 per sash, since the job is slow, hands-on scraping and curing (1). Full restoration of a window, glazing plus minor repairs, averages around $400 and can run anywhere from about $80 to $1,800 depending on its condition (2).
Do it yourself and the cost drops hard. A tub of glazing compound, a few basic tools, and a can of primer come to under $50 total, and one tub seals many windows, so the cost per sash is close to nothing.
How to Reglaze a Window Without Removing It
Sometimes the sash will not come out because it is painted shut or the cords are seized. You can still reglaze it in place (in situ).
The steps are the same, but you are fighting gravity the whole time. Use a stiffer compound and work in shorter sections so the putty does not sag before you can tool it. It goes faster than pulling the sash, but it is harder on your back and arms.
Reglazing vs. Replacing Windows
Should you spend the weekend scraping putty or just buy a new vinyl window? It comes down to the frame’s condition and what you value.
Lean toward a full replacement when:
- Severe Rot: If the frame crumbles when you press it, fresh putty will not save it.
- Efficiency Demands: A single pane will never match a modern double-pane, gas-filled unit on its own, though adding a storm window closes much of that gap.
- Broken Mechanics: If the sash cords and weights are shot and the window will not stay open, a swap can be simpler than a full mechanical rebuild.
When to Choose Reglazing
When the frame is sound, restoration is usually the better call. Here is why the original windows are often worth keeping.
Historical Integrity
Windows built before the 1940s are usually made from old-growth timber, which is far denser and more rot-resistant than today’s fast-grown lumber. A well-kept wood window can last a century or more, while a vinyl replacement typically taps out at 15 to 30 years (3). Vinyl units also look out of place on a period home and can pull down the value of a historic house.
Cost Savings
Replacing every window in a house can run $10,000 to $30,000. Reglazing those same windows yourself costs a few hundred dollars in supplies. When the wood is solid, restoration is the far better return.
Sustainability
Keeping what you already own beats manufacturing new plastic windows. Reglazing keeps old-growth wood out of the landfill, and the U.S. Department of Energy has found that weatherizing and air-sealing an existing window cuts energy use more cost-effectively than replacing it. Federal preservation standards point the same way: repair a deteriorated feature before you replace it.
FAQs
Here are the questions homeowners ask most about the reglazing process.
Final Words
That is the whole reglazing process, from stripping the old putty to the final coat of paint. Work one sash at a time, take your time cleaning the frame and tooling the bevel, and you get back a tight, draft-free window that looks sharp and holds up for decades.
