Maintenance Tips for Double-Hung Windows

Double-hung windows are relatively high maintenance compared to other window types, but they also offer the advantages of being compatible with many home styles; being available in a variety of materials, sizes, and colors; and being easy to clean. If well maintained, double-hung windows should last for generations without needing to be replaced, and they should save on the energy required to heat and cool your home.

Cleaning your windows every spring and fall will not only provide you with a clear view of the outdoors, but it will also offer you the chance to inspect your windows and spot potential problems. Since wood and vinyl are two of the most common materials used in windows, some of the following cleaning tips are specific to these materials. Where frame material is not specified, the tips apply to any double-hung window.

All-wood or clad-wood windows should be regularly cleaned with a mixture of warm water and a small amount of mild dish detergent. The cloth should just be damp—avoid using too much water, as the contact with moisture could encourage rot. Do not use abrasive cleaners or harsh chemicals to clean your wood windows.

Clean vinyl frames with a mild detergent and water, using a soft cloth or soft-bristle brush. Use light pressure because extreme pressure (including the use of a high-pressure washer) could compromise caulking or sealants.

For dirt and stains that are difficult to remove, you can use readily available household cleaners. Do not, however, use liquid grease removers, adhesive removers such as Goo Gone®, strong soaps and detergents containing organic solvents, nail polish removers, furniture polish, or cleansers containing chlorine bleach, as these can alter the appearance of the vinyl.

There are a number of cleaners that work well on glass, from ready-made, ammonia-free cleaners such as Windex® to cleaners you can make at home. If you would like to make your own cleaner, carefully mix your ingredients in a new, empty spray bottle to avoid the possibility of a chemical reaction between the new ingredients and whatever chemical was previously in the bottle. Clearly label the bottle as window cleaner. One homemade option is a mixture of 30 percent white vinegar and 70 percent water. Another option is a mixture of 1 cup rubbing alcohol, 1 cup water, and 1 tablespoon white vinegar. Do not use vinegar on stone or other materials that can react with, or be etched by, acid.

Overcast days provide the best conditions for washing windows; cleaning glass in direct sunlight will increase streaking. Spray your cleaning solution onto the glass and thoroughly wipe off using crumpled black-and-white newspaper, paper towels, or a microfiber (lint-free) cloth. Rub in varying directions to reduce streaking. Do not clean your glass with a high-pressure washer. The extreme pressure of the sprayer may damage the glazing and destroy the insulating seal between the panes.

A nice feature of double-hung windows is that both sides of the glass can usually be cleaned from inside the home.

To clean a window screen, remove it from the frame. Mix a small amount of mild dish detergent with warm water, and use a soft bristle brush or sponge to gently scrub the screen with the soapy water. To avoid damage, fully support the screen material as you wash it. Rinse the screen with warm water, allow to dry completely, and then reinstall it in the frame.

Cleaning the window casing helps reduce the buildup of dirt and debris in the window components, which can contribute to windows becoming stuck. Vacuum any debris from the track and sill for smooth sash movement. You can wash vinyl parts of the window using a non-abrasive detergent and water.

Dealing with problems before they get serious will keep your windows functioning at their best for years to come. The following tips provide an overview of maintaining wood and vinyl double-hung windows.

All-wood frames have been used on homes for hundreds of years. They are favored by many homeowners for their paintability, their overall energy efficiency, and their warm appearance that complements any architectural style. Wood frames, however, require a lifetime of maintenance to keep them working their best. Without proper care, solid wood windows are prone to rot, swelling or distortion of the woodwork, or shrinkage of the wood, which leads to windows that rattle in the wind.

Wood windows should be painted or stained to help seal in the wood's beauty while sealing out moisture. In general, wood frames should be repainted every 3 to 4 years to protect them from the elements and to maintain their appearance. (If you have painted metal frames, these should be repainted every 3 to 4 years, as well.) Spots that have begun to peel or chip should be touched up as needed. Always clean your windows thoroughly before applying paint, and be careful not to paint over moving parts or over a shut window, as the window will get stuck as the paint dries.

When inspecting your wood windows, it is important to check the condition of the window frame and sash. Use a metal probe to look for signs of rot (softened wood), which could indicate that moisture has permeated the wood. The sun, too, can cause certain areas of the frame to become brittle and warp. Promptly attend to any cracks, holes, and splinters in the wood because waiting to address these issues will only result in further deterioration of your window. Grind out or use a screwdriver to remove the rotted wood and get down to solid wood. Fill the cracks and holes with an epoxy putty, using several layers for the best results. Allow the putty to dry, smooth the area with sandpaper, and then apply primer and paint.

An advantage of using epoxy rather than another putty to repair wood is that as wood naturally expands and contracts, epoxy flexes along with it and will not separate. Follow the manufacturer's instructions for using epoxy putty.

Vinyl frames require significantly less maintenance than wood frames, but that does not mean they are entirely maintenance-free. To keep the window operating smoothly, the contact points should be lubricated once per year after the window has been cleaned. Always use a silicone-based lubricant, never one that is petroleum based. Spray dry silicone on a clean cloth and rub onto the side jambs of the window to lubricate them. Open and shut the window a few times to evenly distribute the lubricant.

Check for signs of moisture between the panes in double- or triple-paned windows. Symptoms of moisture infiltration are beads of liquid or fogginess between the panes of glass. Moisture indicates that the seal has failed, reducing the insulation capacity of your windows. If you see this, it means that the pane or panes need to be replaced. Repair any cracked or broken glass immediately to prevent air leaks and accidental cuts by broken glass.

Condensation you can see and touch on your windows is called interior condensation, and it is caused by excessive moisture inside your home. It often occurs in the winter when the warm air inside the house condenses on the cold windows. If not dealt with, interior condensation can rot wood windows and damage walls. Some simple ways to address this problem include turning down your home's humidifier, using a moisture-eliminating product such as DampRid®, running your kitchen or bathroom fan for about 20 minutes after you cook or shower, and running your ceiling fans in a clockwise direction in the winter to push warm air off the ceiling and back down to the floor.

Windows can stick shut for a number of reasons. Reasons such as structural settling of the house or age-related bowing of the window frames are more serious problems that may require a full window replacement. Many times, though, the problem can be resolved in a few simple steps.

Wood windows: It is not uncommon for painters to paint wood windows in such a way that when the paint dries, the sash is stuck. If this occurs and you don't need to open the window (for example, if it is winter), one advantage is that this may give you a weather-tight seal. If you do want to open the window, though, run a sash saw, sharp utility knife, putty knife, or paint zipper between the sash frame and the channel to break the seal. One pass should be sufficient.

If dried paint is not the reason the sashes are sticking on your wood window, rub ordinary wax (e.g., the bottom of a white candle) against the bottom and sides of the sash so it will better slide in the channel. A light coat is all that is necessary. Open and close the window several times to distribute the wax and lubricate the surfaces. Applying wax once per year will keep your windows operating smoothly.

Check the window tracks for dried paint. Window tracks are not meant to be painted but often are. You may help the window move more freely by scraping away any loose paint and lightly sanding the window tracks. Also, vacuum the tracks to remove all dust and dirt and then use a clean cloth moistened with furniture wax to wipe them clean.

Vinyl windows: To unstick a vinyl window, remove the sash, clean the vinyl tracks, and wipe the tracks with a thin layer of silicone lubricant. Repeat this maintenance yearly.

Vacuum the tracks to remove all dust and dirt and then use a clean cloth moistened with a household cleaner to wipe them clean.

With both wood and vinyl windows, never use a penetrating oil, such as WD-40®, to lubricate the tracks. Doing so will only offer a temporary solution and will eventually serve as a magnet for dirt and grime, making your window stickier than ever.

Caulk is used to seal stationary cracks, gaps, or joints that are less than ¼-inch wide, which prevents air leaks. Apply caulk in conditions of low humidity when the temperature is above 45 degrees Fahrenheit. On the outside, apply caulk between the window molding and the house. On the inside, apply caulk around the window trim.

Applying weatherstripping to movable components of a window is a relatively simple and inexpensive way to save 10 to 15 percent on energy bills, block outside drafts and noise, and keep out dust and insects. A double-hung window has several potential points where air can leak: between the upper and lower sash, along the sides of the sash, and where the bottom sash meets the stool (the interior "sill"). There are a number of different types of weatherstripping. Choose one that will best withstand temperature changes, friction, weather, and wear and tear associated with your location. Weatherstripping should be applied to clean, dry surfaces when the temperature is above 20 degrees Fahrenheit and should compress when the window is shut.

If you live in a home that was built before 1945 and still have the original double-hung windows, it is likely that your windows operate with a system of cords and pulleys attached to metal weights inside pockets behind the case moldings. This kind of windows is sometimes known as a ballast window. These weights, made of iron, steel, or lead, are hidden in pockets on either side of the window and are used to counterbalance the weight of the window, allowing it to move up and down easily. The longevity of the materials that make up the components in these windows, coupled with their repairability, has many of these windows still functioning after nearly 100 years of use.

If the lower window is hard to lift upward, or if the window won't stay open and slams shut sharply, it may be that the cord-and-weight system is malfunctioning. This is often because the cords that link the weights to the sash have broken. In this case, the window needs to be removed and the broken sash cords repaired. This is not a hard job, provided the window frames have not been painted. But if they are painted, you should probably hire someone who is trained in lead-safe work practices since it is likely that lead-based paint was used on your windows. You can check the website of the Environmental Protection Agency for a list of certified professionals.

Given the expense, this decision is often a difficult one for homeowners. Windows help define the look of your home and are an important architectural detail. This is especially true if you live in a historic home that still has its original windows. Check with your local preservation commission for guidance and a list of skilled contractors who are qualified to do repairs. Consider the methods for improving energy efficiency described above. Remember that you or a professional may be able to repair rot, jammed sashes, or broken parts.

If you see signs that water has penetrated around the frames if the house has settled to where the windows won't open, or if the frames are bowing due to age, replacing the windows may be the most cost-effective option. Though it will take years to recoup the expense, the windows will eventually pay for themselves through lowered heating and cooling costs.