It is important to note that this article is written for experienced DIY specialists only and not first-timers. If the reader feels like the tasks outlined here extend beyond what they know about replacement windows, don’t try any at home.
This will be most crucial to single and double-hung window owners as this style specifically develops a reputation of having the most number of complaints regarding slider support systems. This is a direct result of poor maintenance, poor quality materials, and poor durability of the product. How smoothly a sash slides up and down and stops depends on the wood window’s stile, parting stop, slider rail, jamb, and sash weight - any defect could be one of, or any combination of, these components. Looking at each of these elements should solve the problem of a sash that’s too stubborn or loose to operate.
Before Purchasing a Brand-New Window
When stiles of a window wear out, expand, contract, break, or detach for whatever reason, don’t immediately give in to buying a new replacement. Don’t worry about getting exactly the right material for a new stile to match with the rest of the window, different paints and window finishes are there to help mitigate the appearance as if the stile were never changed.
- Drill & drill bits
- Screws & nails of the right sizes
- All-purpose screwdrivers
- Sash cord
- Safety goggles
- Dust mask
- Thick work gloves
- Measuring equipment
- Paint (if the window is a solid color)
- The right wood species (e.g. mahogany, sugar pine, VGDF, etc.)
How Old Is the Window?
Modern single and double-hung windows make removing the sash from the rail effortless. MI Windows, for instance, feature a pull-handle on either side of the meeting rail that, once pulled, swing the sash inward to pull the pivoting bars still tightly tucked in snug rubber hoses facing the inner stile out of their grip. Afterward, it’s simply a matter of detaching the defective stile.
Conversely, however, older windows don’t have this easy-going feature and will require a removal of the inner casing on the person’s part to successfully release the sash unscathed. Unless replacing the inner casing is also a part of the DIY project, the trick is to pull the nailed inner casing a fraction of the way out of its original position, make a series of snappy pulls (while wearing gloves), and ensure that no damage happens to the rest of the trim.
Step 1: Remove the Sash
Now, go ahead and remove the problematic sash from the frame. It should be as easy as pushing the side rail further to one side until there’s enough slack on the other side to pull the sash out entirely. However, the cord attaching the sash to the sash weight still needs to be cut, but don't worry about preserving it since replacing it is easy.
Step 2: Cut Along the Joining Line
When the sash makes it to the work desk, get a box cutter and run the sharp edge along every line of the stile to be replaced joins with the rest of the sash – this is to make some room for a flat screwdriver to break the stile free and to cut dried-over paint from slowing the work down.
Step 3: Detach the Stile and Cut the New Piece to Size
Clamp the stile to the work desk and start unscrewing the stile from the sash or pull it free if it’s fastened on with nails. Next, take the lumber block and cut it to size along the pencil-marked areas using the buzz saw. Don't forget to cut a tube like cross-sectional downward hole identical to the old one's length. Now, from the outside, puncture a hole in the wood until it meets the other end of the cross-sectional line at a right angle. This is where one end of the sash cord is going to stick out in a knot to keep the sash from falling.
Step 4: Sand the Wood
Avoid sanding the wood AFTER joining the stile to the sash, as this will form cross-scratches to the final product and show unpleasantly obvious signs of amateur craftsmanship. Use an orbital sander to leave no trace of cross-scratching.
Step 5: Clean the Wood
Scrub any remaining wood pieces from the newly built stile with a short brush, rinse it with water, and leave it to dry for some time. Don’t start applying stains, paint, or oils until the new stile has completely dried off. Any remaining moisture that wasn’t given a chance to evaporate from the microscopic gaps in the wood will crack and rot the wood much faster than anticipated.
Step 6: Polish the Wood
When window shopping for different stains, don’t rely too heavily on the colors on display. Those colors are primarily a product of the wood species combining with the grain mixture. To make sure, get practice wood blocks to experiment with different stains and finishes for just the right look and feel. For a preferred finish, take the Linseed oil, mineral oil, special wax-oil combination, or other option and apply it to the wood. If the yellowy tint is the final look one is going for, choose Linseed oil; for a smooth and glossy finish to the wood, apply a film-forming oil such as Tung oil.
Step 7: Replace the Old Sash Cord
After screwing or nailing the stile in the older one’s place, it's time to cut the old cord and replace it with the new. The sash weight typically suspends from the cord knot. Cut it loose, remove the cord, and insert the new cord along the old one's path and tie a knot accordingly. Before placing the sash back inside the adjacent rails, place it on the stool and let it lean. Take the other end of the cord and slide it inside the vertical cross sections in both stiles. Pull just enough cord out the other end of each cross section and make firm knots to ensure optimal control.
Step 8: Insert the Improved Sash
Finally, slide the sash back into the slider rail. The improved window will now run smoothly and look fantastic.
This article is meant for purely educational purposes only and is not meant to impart action in inexperienced homeowners. Amateurs are meant to steer clear of any handy work expressed above if they’re not going to take responsibility for any accidents that may befall them.