How to Rebuild a Sash Weight Window
Rebuilding a window with sash weights is a pretty simple process. Many times the home may have historical value so the window styles must be maintained or there is no replacement window available that exactly matches. Here are some suggestions.
Windows with sash weights were common for many years and only in the last forty years or so have vinyl or wood windows with spring balances become common. Sash weight windows usually have single pane glass making them very inefficient against heat loss as well. Years of operation has caused wear of the wood tracks and the sash themselves causing even more air leakage.
Start by carefully removing the inside window trims if they are to be reused later. Carefully prying the trim off the finish nails and then removing the nails, helps prevent damage to the trim surfaces from hammers and pry bars. Never pry directly against the trim itself. If you must pry on the trim face, place a piece of wood under the hammer claw or pry bar to avoid direct pressure on the wood. If new trims are to be installed, simply discard the old trims unless they can be recycled elsewhere in the home or maybe Habitat.
Once the all trims are removed look Sash Window Repairs Kent carefully in the window track slot at the bottom with the sash in the up position. You will see on each side of the window a small door recessed into the track slot itself, held in place with two large slotted screws.The screws may be obscured by years of painting but careful scraping will reveal an indent where the screws are countersunk. Carefully remove the screws and then gently pry out the wood door piece on each side. Grasp the inner sash firmly and give a tug on one side to pull the sash out of the window frame. There will be a rope on each side of the window connected to the top of the sash as well to an iron weight concealed behind the window track. Carefully and with a firm grip on both the sash and the window cord, twist the knot out of the window top. The window will come free. I repeat have a firm grip on the sash cord. The weight is much heavier than you think and will want to crash down into the window pocket if released. Slowly raise the sash cord until the knot comes into contact with the recessed pulley at the window top.
Repeat the process for the opposite side. Set the sash aside making sure you know which is the top and the bottom sash. Place a wood block into the track opening and cut the card knot. The block will help catch the sash weight and allow you to pull it out of the pocket. Remove the pulleys. The pulleys and the weights will no longer be used.