How to Repair Old Windows Instead of Replacing Them

Many people believe that drafty old windows that are hard to open and close need replacement. However, in most cases, windows can be repaired. Repairing an old window is not only more cost-efficient than replacing it, but is often desired when dealing with older homes whose windows have historic value.

Look here to familiarize yourself with some basic window terminology.

Let's look at the problem of drafty windows. There are two main reasons why old windows are drafty: insufficient insulation and cracked and/or missing putty. To add extra insulation, first you will need a hammer and pry bar to remove the interior casing surrounding the window frame. Then, cut some rigid foam insulation to match the size of the spaces between the side, top, and bottom jambs and plaster/drywall. Spray some expanding polyurethane foam into the top and bottom, and far left and right, spaces of the windows jambs. Now, press in your pieces of rigid foam insulation. Cover the seam made between the wall and the insulation with adhesive foil tape and replace the casing.

Window glass is held in the window frame with either caulking or putty. Over time, the putty or caulk will crack and fall away, leaving the window drafty. It may even lead to the window pane falling out! To resolve this issue, purchase fresh putty or caulking, and also a putty knife. Using the putty knife, scrape away all loose putty/caulking. In the process, the window pane may itself become loose. Be sure to keep track of any sash clips or push points that fall out, as they will need to be placed back into the window frame.

Once all the loose putty and/or caulking has been scraped away, use your putty knife to apply new putty around the window pane edges. Scrape away any excess. Alternatively, use a caulking gun to apply caulking, making sure to wipe off the excess. Let the putty or caulk set for at least a week before opening your window.

The second most common problem with old windows is that they are difficult to open and close. The fault usually lies in the window's weight-and-pulley system, a common feature of older double-hung windows. Basically, the weight-and-pulley system relies upon a counterweight to allow for the opening and closing of a window. The weight is hung by a cord, and the cord's end attaches to the bottom of the window sash. There are two such weight-and-pulley systems per window.

Over time, the cord can become mildew-infested and decay. The cord may also become covered with paint, glue, or other adhesive materials which render it difficult to slide between the window frame and sash.

Oftentimes, it becomes necessary to replace the weight-and-pulley system. To do this, remove the window casing by pulling the bottom sash away from its frame. This will expose the cords. Cut the cords with a knife and let their weights slowly descend into the holding boxes. Remember to cut the cords on both window sides. Remove the bottom sash completely out of its frame.

Remove the top sash in much the same way, keeping in mind to also remove the parting stop that divides the top and bottom sashes from each other.

After this is completed, unscrew the covers from the weight boxes. Record just how the cords are tied to the weights. After undoing the remainder of the cord from the window sash, measure its total length. Also, remove and check the pulley inserts, which may be corroded or broken. If they look intact, re-install them back into the window frames.

Finally, weigh each window pane on a bathroom scale. This step is important so that you know what weights to buy, just in case the current ones are incorrect (as often happens when window frames or panes are replaced during the life of a window).

Go to your local home improvement store and find out whether your window's weight was appropriate to the weights provided. Sometimes, weight limits are engraved on the weights themselves, but older weights may no longer carry this information (or it may have worn off). If all else fails, buy new weights. Of course, you will also need fresh cord, and possibly new pulleys.

When you get back home, attach the new cord to the weights. Measure out the same amount of new cord as measured for the old weights. If all else fails, keep in mind that when the sash is in its lowered position, the counterweights should just reach the top of the frame sleeve. When the sashes are raised, the counterweights should dangle just above the bottom of their boxes. After attaching the appropriate lengths of cord, screw the weight box covers back in place. Slowly let down the weights for each sash into their appropriate boxes. Now rethread the cord through the pulley and attach it to the respective window sash.

Reinsert the outer sash first, then the inner sash. To insure that both sashes move smoothly, grease their edges with some WD-40 first. Make sure the outer sash is snapped securely into the frame before moving on to the inner one. Also, before re-inserting the inner sash, replace the parting stops that you took out before. Fasten the stops with nails, using a nail set to push them below the surface.

Once your inner sash in snapped into place, you are done. You windows should now open and close with ease.

In conclusion, by properly repairing your old windows, you can avoid paying for costly replacements.