Windows are probably a part of your home you give little thought to, until there is a problem. Leaky windows can be a major annoyance, but they can lead to other, more serious problems as well. Conversely, solid windows are a great investment, adding value to your home.
There can be many causes of leaky windows. This can make zeroing in on solutions a challenge.
This article covers the main reasons for a leaking window, along with appropriate fixes for each. Keep reading to find out how to ensure your windows are sealed and secure, and how to prevent window leaks in the first place.
Why Leaking Windows Matter
There are many reasons you should address a leaking window. One is energy waste.
Leaking windows allow air to escape from a room. This translates to higher heating or cooling costs on your utility bill.
Leaks also make it harder to regulate the temperatures in the room with the leak. You may notice frequent cold spots during winter months or hot spots in summer.
Another issue with a leaking window is that it gives water a better opportunity to get into your home. This can cause damage, such as rot on wooden surfaces.
It could cause mold or mildew growth. This is a structural concern but could also lead to health issues, such as allergic reactions or respiratory problems. Finally, leaks in caulking can leave space for pests to infiltrate the building.
Common Causes of a Leaking Window
There are many different causes of a leaking window. Here are the main ones you are likely to encounter.
Damaged or Deteriorated Caulking
Caulking is a flexible material used to seal various surfaces, including windows. It can be made from different compounds, but silicone, latex, and polyurethane are the most common.
Caulking around window frames can degrade over time. This is often due to sunlight exposure, temperature changes, or weather (or a combination of all three). Excess moisture and humidity can damage caulking over time as well.
These factors can cause caulking to dry out, become brittle, and crack. This leads to gaps and openings that produce leaks.
Caulking also can become damaged from the settlement of buildings. Even the slightest shifts in windows can result in separation from the substrate, resulting in cracks and leaks. Caulking can also become damaged from physical impacts.
Poor Window Installation
Improper installation is a very common cause of leaking windows. They need a snug fit in the opening. If they are not installed correctly, it can result in gaps that form around the edges.
Improper fit is a major culprit here. No amount of caulking or other adjustments can compensate for a window that is too small for the rough opening where it sits.
Another common installation issue that can lead to leaks is the lack of a backslope during installation. Proper window placement allows the opening to tilt slightly downward towards the outside of the building, to ensure proper drainage.
Finally, a common mistake with poor window installation is improper sealing. In some cases, the installer might use the wrong type of caulk. For example, latex-based sealants may be appropriate for interior windows, but they are not as weather-resistant as silicone-based ones.
Damaged Glass
You might assume that damaged glass is an easily identifiable cause of window leaks, but it is one that often flies below the radar. Major cracks in glass are obvious, but very often leaks occur near where the glass joins the window frame.
Also, do not overlook minor chips or cracks in window glass. Even small cracks can be enough to let air or moisture in.
Another sign of damaged glass is condensation between panes. If you have double-paned windows and notice a buildup of moisture, it is likely due to a small crack in one or both of the sheets of glass.
Damaged glass tends to worsen over time. For this reason, it is best to address seemingly insignificant damage before it turns into a major problem.
Faulty Flashing or Weather Stripping
Another common cause of leaky windows is damaged or poorly installed flashing or weather stripping. Flashing is the thin, waterproof material that goes around the window frame. It is meant to direct water away from the building (and window).
Weather stripping goes around the edges of the window sash. It helps create a tight seal when the window is closed.
If flashing is damaged or missing, then water can accumulate around the window and cause damage and leaks. If weather stripping is worn or damaged, it too can allow water or air to enter around the edges of the window frame, even when the window is closed.
Fixing Window Leaks
Now that you know the common causes of leaking windows, you can decide on appropriate solutions. Here are the fixes corresponding to the issues discussed above.
How to Repair Damaged Caulking
The best course of action for repairing damaged caulking depends on the nature of the damage. For new caulking, it may be possible to reseal leaking areas. However, if the damage is due to degradation over time, then the caulking should be completely replaced.
Use a utility knife or scraper to cut away the old caulking. If it is difficult to remove, apply a commercial caulk softener to them.
Next, use a damp rag to completely wipe down the area around the window frame. This will remove any dust, dirt, or debris.
Load the caulk tube into a caulk gun. At a 45-degree angle, apply the sealant to fill the gap between the window and the siding or trim.
Finally, smooth the caulk using a wet finger (so that it does not stick). This will create a seamless, even bead.
How to Fix Improperly Installed Windows
Unfortunately, in most cases, improperly installed windows require removal and reinstallation. If the window is visibly crooked, it likely is the wrong size.
Keep in mind that the issue may be structural instead of with the window itself. Check the dimensions and integrity of the opening before purchasing new windows.
If the wrong type of caulk was used, it needs to be removed and replaced (see above) with the correct kind. If you are uncertain of the problem, then relying on a professional to reinstall the window will ensure proper fit and function.
How to Repair Damaged Glass
Like other issues on this list, the proper repair for compromised glass depends on the extent and type of damage. It may be possible to fix very small chips or cracks without replacing the entire frame. Commercial repair kits allow you to inject a clear resin into the damaged area, sealing it.
For more serious cracks or shattered window panes, completely replacing the glass is the best course of action. Replacing glass panes is possible without replacing the entire window. When doing so, wear protective glasses and gloves to avoid injury.
First, remove the sash holding the glass pane in place. Much like with caulking, use a putty knife or other tool with a rigid edge to remove the compound holding the glass in place.
Clean the frame of any debris, including any glass shards that may have remained. Replace the glass with the right size pane and caulk around the edges. Reattach the sash.
Double-paned windows can be much more complex to replace. That is because you need to maintain the vacuum seal between the panes. Replacing them may be best left up to a professional.
How to Repair Flashing and Weather Stripping
If flashing is installed incorrectly but still intact, you may be able to adjust it without replacement. For instance, if it is separated from the wall, securing it may suffice to fix the problem. You may also be able to repair minor holes or tears in flashing pieces using roofing cement.
With damaged flashing, you may be able to replace only the damaged portions, such as side, head, or sill flashing. Use a crowbar to remove it.
Replace it with a new piece of flashing. Aluminum or galvanized steel are good options. Use caulking to secure it to the wall and window frame.
In most cases, damaged or deteriorated weather stripping needs to be replaced. To do so, pry out the old stripping using a putty knife. Be careful not to damage the window frame in the process.
Wipe down the frame and the channel where the old stripping sat, and allow the surface to dry. Measure the length of the space and cut the new stripping accordingly.
Some weather stripping is self-adhesive. Simply peel the backing paper away and press the stripping into the window frame. Other types require you to use small nails at predetermined intervals.
Learn More Window Maintenance Tips
Now that you know the main causes of a leaking window and the corresponding fixes, you can move forward with the repair. A reputable window installation company can further assist you with identifying issues and the appropriate responses.
Complete Window Care is a family-owned business serving Colorado Springs and the surrounding areas. We offer a variety of services, including new window installation, glass replacement, and frame and screen repair. Reach out to us today to schedule an appointment for window leak repairs or other leaky window solutions.
