Sash Replacement Kit: A Little-Known Fix-It for Bad or Broken Windows

Double Hung Windows 157082588
Double Hung Windows. Getty / Paul Viant

Did you know that instead of investing in expensive replacement windows you can buy something called a sash replacement kit?  Yes, you can bypass the expensive process of completely replacing broken or poorly performing windows just by replacing the window sashes--the part of the window that moves up and down.

Window sash replacement kits let you replace just the top and bottom sashes, keeping the window framing and other key architectural elements.

Total Window Replacement Is Costly, Often Unnecessary

New replacement windows for your entire house can easily set you back $30,000 or more.  Do-it-yourself window replacement can be a daunting prospect for most homeowners; this is almost always something that a window company must do, which drives up labor costs.

Even replacing a single window can cost $400-$500. Unless the frame is rotted out or otherwise compromised, you can replace the sash only.  By keeping the framing, you also get to keep the exterior window casing, another big job.

3 Essentials for Window Sash Replacement:

  • Sashes Go By Brand Name: There are no generic kits; you'll need to search for your window's brand name. Kits are not transferable from one brand to another.
  • Contents of Kit: Usually a kit comprises a top and bottom sash, compression jamb liners for both sides of the window, a sill dam, and a head parting stop.
  • Not Widely Advertised: Window companies don't trumpet the availability of the replacement kits because it cuts into their sales of replacement windows. But they are out there if you look hard enough.

    Removing the Sash

    There are two chief ways of removing the sash, depending on whether you have an older or a newer window. For older windows (wood), sash removal is mainly done only if the sash needs to be replaced or the window needs to be repaired because you'll need to pound out part of the window and replace it.

     For newer windows (vinyl, etc.), sash removal is relatively easy; no deconstruction is involved.

    • For Older Windows Made of Wood:  Wood windows will usually have what is called a "stop." As the name implies, this thin vertical strip of wood stops the window sash from coming out.  Score the edges of the stop with a utility knife. Gently pry off the stop with a flat screwdriver or small prybar.
    • For Newer Windows Made of Vinyl, Fiberglass, and Metal:  Newer windows usually have a spring-based balance mechanism.  With one hand, depress the outermost flexible track.  With the other hand gently pull inward on the top of the sash. With half of the sash out, the other half will pivot out.

    Paint Your Sashing

    Should you paint the window sash before or after installing it? It sure is a tempting thought to paint a sash on a sawhorse in your backyard or basement rather than painting it vertically in place.

    But you can compromise the operations of your new sashes if you paint them before replacement. For one thing, you should never paint the operable side of the replacement sash (the part that slides in the window channel). But even if you do not paint that section, drips can run down the sides—drip which can affect operations if you do not scrape or sand them off.

    Generally, it's a better idea to paint your window sash after installation.

    Balancing Weight: Snip It or Save it?

    In older windows with wood windows, after sash removal you are left with the balancing weight:  a heavy lead or iron cylinder attached to the movable sash with ropes. Keep it or snip it?

    Snip it. In most cases, the replacement kit will have a balancing mechanism to keep your new sash in place and properly moving up and down.  Essentially, your home is being updated from weights to spring-loaded mechanisms, rather you like it or not.

    Obviously, if you are buying salvaged sashes from an architectural salvage store, there won't be any balancing mechanism. So, use your best judgment when deciding what to do about the sash weights.