How to Rebuild an Original Wood Window

The most common—and quite costly—error made by homeowners is needlessly replacing original wood windows. So many times I have seen homes in the process of having all of the original windows replaced, but never have I seen a window that was beyond restoration. Even with enticing rebates, it makes financial sense to preserve your vintage home’s original details—including the windows.


Designed to last

Original Wood Window

New and modern is not always better. In fact, original windows’ old-growth lumber is solid, firm and resistant to decay. For less than the cost of replacement, wood windows can be made to last another 90-plus years. When an original sash window is rebuilt and well-maintained, it can be opened and closed with ease. Properly weatherized wood windows perform as good or better than new windows.


The most common windows found in vintage homes are casement and/or sash. Sash and casement windows share the same maintenance issues in regards to periodic reglazing with window putty. For window glaze, Dap 33 is the pros’ choice.


On the Case

Casement windows have only two simple moving parts: hinges. So if there’s trouble, it is almost always solved at the hinges. Either the hinge screws are loose or the hinges need shims.

1. Examine the entire opening. If the gap is not even on all sides it is likely a hinge problem.


2. A one- or two-layer thin cardboard shim properly placed will usually solve the problem.


3. It is possible that there’s too much paint buildup at the edges of the window or casement, in which case it is recommended to chemically strip. Remember: Once you remove the wood it is gone forever. Only plane the edges of a window as a last resort if the casement has become out of square.


Double Your money: How to Rebuild a Sash Window

The double-hung sash window with its ropes and pulleys is the ultimate in design efficiency. Just about any wood window can be saved; when necessary, I’ve purchased junk windows with similar dimensions to replace whole sections that were damaged or warped.

Here’s how to perform a full rebuild job on a sash window for a low cost:

Getting Started

1. From the inside, open the cavity where the weights are. Remove all lumber intact by using a utility knife with a fresh blade to score and break the seal of paint or varnish at every joint where wood pieces are to be removed as well as around any windows painted shut.


2. Take a one-inch, hook-shaped scraper and remove the paint buildup on the inner edges of the stop beads. Next, remove the two vertical stop beads (leave the horizontal one in place).


3. Remove trim pieces intact with a stiff-blade putty knife or a dull chisel and a hammer to begin the prying; use a crowbar to finish the job. Work from the top down, alternating with all the nails.


4. When the piece is removed, pry off all the old nails from the back side of the wood—never from the front. On a whole house job, it is likely some pieces will crack, splinter or split. The easy fix is to glue the pieces and wrap tightly with blue painters’ tape. If in a hurry to reinstall, set these in the sun, and you’ll be ready to go in an hour.


Sashes to Sashes:

Removing the windows

1. Carefully remove the lower sash window that is close to you. If ropes are still attached to weights, cut them with a knife, but first inspect the upper window, because if the ropes are off it could come down like a guillotine. Prop it up if necessary.


2. Remove the vertical casement boards to expose the weights. Who knows what treasures you may find in there? One client needed me to replace sections of damaged horizontal head casement. To my joy, I opened up a weight cavity to find some original Douglas fir pieces—enough for the whole job—stashed there when the house was built!


3. Remove the upper sash window. First, remove the parting bead vertical molding that separates the two sash windows. Only remove one by wiggling it out with pliers, the teeth wrapped in a cloth. If someone has foolishly nailed them in they will come out in pieces, and you will need to get pine replacements at your lumberyard.


4. If you are one of the lucky few homeowners whose sash runs are not caked with paint, proceed to the re-roping section. Otherwise, use a stripper such as Soygel to remove all paint from the sash runs, parting bead and any surface that will come in contact with a traveling window. Note: Never use a heat gun on a frame unless you are planning to collect on your homeowner’s insurance policy!


5. Once the sash runs are stripped, you can stain the wood to match your interior and seal them with boiled (not raw) linseed oil. Never use any kind of coating that dries to a hard film.


Hanging by a Rope

1. Re-roping starts with lubing the pulleys. Go to a hardware store for the sash rope (that is what it is called). Bring a sample of your original to match up the diameter.


2. Vacuum out the channel and clean everything in the area—including your hands so that you won’t dirty the clean white rope.


3. Cut a piece of rope about the length of the sash run. Allow extra length on your first attempts until you get the “hang” of it. On one end, tie a very tight single knot with about one-inch excess. If the round bore in your window side will easily accommodate a larger knot, tie a second single knot over the first to create a knot ball twice the size.


4. Feed the other end over the top of the pulley and into the weight cavity, and tie it to the weight. Tie a double knot (two stacked) and test the window before reinstalling any trim pieces. Make sure that when the weight is at its highest it never touches the pulley and at its lowest it never bottoms out. The weights must always hang suspended.


5. Put everything back in the reverse of how it was removed. Make sure that the two windows open and close all the way. Button it up with nails generally a little smaller than the originals and a few less. You are now ready for another 90-plus years of reliable service.


By Michael Logan

Leave a Reply
