A leaking window can be caused by many things. While repair is possible in many cases, the window’s age may mean it’s time to consider replacement. Windows have an average lifespan of about 20 years, but various factors can cause window sealant to deteriorate at different rates. Water and other weather-related damage can wreak havoc on windows.
If you’re not sure how to address a window leak, or you think you need new window installation, call 855.608.1580 or contact us online for a free quote and expert installation. The Master Seal team specializes in window installation in Maryland.
Table of contents
- Install a sliding door security bar
- Add a sliding door pin lock
- Install anti-lift locks or screws
- Add a foot lock or deadbolt
- Apply window security film
- Install glass break sensors and door sensor alarms
- Why sliding glass doors are a common security weak point
- Frequently asked questions
- Make sliding doors safer with help from Master Seal
A leaking window can be caused by many things. While repair is possible in many cases, the window’s age may mean it’s time to consider replacement. Windows have an average lifespan of about 20 years, but various factors can cause window sealant to deteriorate at different rates. Water and other weather-related damage can wreak havoc on windows.
If you’re not sure how to address a window leak, or you think you need new window installation, call 855.608.1580 or contact us online for a free quote and expert installation. The Master Seal team specializes in window installation in Maryland.
Where is the leak actually coming from? (Diagnose before you repair)
The first step in any window leak repair is finding the true source of the water, because the spot where water appears inside your home isn’t always where it enters the building. Take time to diagnose before you reach for the caulk.
Most window leaks trace back to one of four locations. Water pooling at the bottom of the frame or sill often points to clogged or missing weep holes, the small drainage openings built into the lower track. Fog or moisture trapped between the glass panes signals a glass seal failure inside the insulated unit.
Water showing up around the frame perimeter usually means the frame sealant has failed where the window meets the wall. Water running from the top of the frame frequently comes from above the window, such as gutters, siding, or roofing.
A simple hose test is the most practical way to narrow things down. Ask a helper to run a gentle stream of water along one section at a time, beginning at the bottom, then the sides, and finally the top. Wait a few minutes between passes, and when water appears indoors, note which section was being sprayed. That will show you whether a window seal is broken or the leak comes from the frame, the drainage system, or somewhere above.
Window leak causes and repair
Once you have identified the general source, decide whether a do-it-yourself sealant repair will work. Caulking a window includes:
- Cutting out the old sealant
- Cleaning and drying the joint
- Applying a continuous bead that is tooled smooth
Choosing the best caulk for windows, usually a high-quality exterior silicone or polyurethane sealant rated for weather exposure, makes a big difference. The causes below explain how leaks begin, and the repair steps cover the basic fix.
Causes
A window leak can be caused by a variety of reasons. Even if the window frames and glass look good, the compounds that hold the parts together can break down over time, letting water leak in around the window or glass. Window hardware can also be damaged, causing the window to not close properly and letting water in.
If you recently had windows installed and are finding leaks, this is a red flag that they were either installed improperly or the windows themselves are faulty. In this case, consult the installer to have them fix it.
Repair
Once you think you know the source of the leak, you can decide whether to fix it yourself or call in a professional. If the window sealant is the issue, you can remove the damaged sealant and reapply it.
After it fully dries, test it by spraying a hose along the edges you replaced to see whether water still leaks. If that doesn’t work, or the leak is worse, call professionals in the window industry, like Master Seal in Baltimore.
Clogged or missing weep holes
A window weep hole is a small drainage opening built into the bottom of the window frame or sill. Its job is to let water that collects in the track drain back outside instead of pooling and spilling into your home. Over time, dirt, debris, paint overspray, or nesting insects can clog window weep holes. When openings are blocked, water backs up in the track and finds a way inside.
The most common signs of blocked weep holes include:
- Water sitting in the sill or track after rain
- Leaks that appear only during heavy downpours
- Mold or mildew forming along the lower frame
If you notice puddles inside the bottom track long after the rain stops, inspect the weep holes first.
You can usually clean window weep holes yourself with a soft brush, pipe cleaner, vacuum, or small wire. Work gently, and never caulk or seal over weep holes, because these openings are meant to stay clear, and sealing them will trap water inside the frame and make the leak worse.
Glass seal failure vs. frame sealant failure
It helps to separate two problems that homeowners often confuse. Condensation between window panes that you can’t wipe away from either side means the insulated glass unit has lost its seal, which is a window seal failure. Water entering around the outside edge of the frame points instead to frame sealant failure.
A window seal failure inside the glass generally means the insulated glass unit itself needs replacing, because the gas between the panes has escaped and cannot be resealed by hand. If the frame is otherwise sound, replacing just the glass unit can be more cost-effective than replacing the entire window. Frame sealant failure is usually a simpler repair that involves removing old caulk and applying fresh exterior sealant around the perimeter.
Keeping the glass seal intact matters for more than moisture control. Remember that windows account for roughly 25% to 30% of residential heating and cooling energy use.1 Foggy glass is a sign to investigate, while a wet wall around the frame is a separate issue with its own repair path.
Upstream causes: Gutters, siding, and roofing above the window
When your window leaks from the top, the water source is often not the window. Leaks concentrated along the upper edge of the frame usually point to a problem above the window, where water gets behind the exterior surface and runs down the wall until it reaches the opening.
Clogged or overflowing gutters can spill water down the face of the house and overwhelm the area above a window. Damaged or missing siding lets rainwater reach the sheathing and the top of the frame. Flashing is the metal or membrane barrier that diverts water around windows and roof penetrations, and gaps or rust in flashing allow that water to reach the frame.
Before you assume the window has failed, check the gutter above it, the siding, and the flashing at the window head and roofline. Clean the gutters, look for cracked or lifted siding, and inspect the flashing for gaps or rust. If these repairs stop the leak, you have saved yourself the cost of replacing a window that was never the real problem.
Your options for replacement window installation in Maryland
If window replacement is the best option, choosing the right window type matters. You will need to decide whether to replace just the leaking window or all your windows for consistency. Next, prioritize your needs, such as energy efficiency and aesthetic preferences. Wood and vinyl windows are both popular options today. Each has pros and cons, depending on your priorities.
Repair usually makes sense when the leak is caused by worn sealant, a clogged weep hole, or a small flashing gap. Replacement is the better choice when the frame is rotted, the glass seal has failed, or repairs have already failed. In the vinyl vs. wood windows debate, vinyl generally lasts longer and needs less maintenance, while wood offers more design flexibility.
A strong signal that replacement is the right call is rot that has reached the structural frame. Surface wood window rot can sometimes be repaired with epoxy or wood filler, but rot that has softened the sash or frame usually means the window has reached the end of its service life. A persistent leak that returns after resealing, or fogging between the panes, also points toward replacement.
Vinyl
- Vinyl windows are cost-effective in many ways
- The PVC material used to manufacture vinyl windows is less expensive than wood
- Vinyl windows are also easy to clean and maintain
- They aren’t as customizable as a wood window that is easily painted
- They are very energy-efficient
- They aren’t a recyclable material
Wood
- Wood windows also have an additional exterior layer of a material like PVC or aluminum to protect the wood frame from the effects of weather
- Wood windows add a classic feel to any home
- They are well-insulating
- Wood can be easily stained or painted to fit a variety of design aesthetics
- They are more expensive than vinyl windows
- They can require more regular maintenance
- They are more susceptible to damage from severe weather
Frequently asked questions
A window weep hole is a small drainage opening at the bottom of the frame that lets collected water drain outside. When these openings clog with dirt, debris, or paint, water backs up in the track and can leak inside. Never caulk over weep holes, because they need to stay open.
Condensation between the panes that can’t be wiped away means the insulated glass unit has lost its seal. The glass unit usually needs replacing, though the frame may still be sound. Replacing just the glass often costs less than replacing the whole window.
A leak at the top of the frame usually points to a problem above the window. Clogged gutters, damaged siding, or failed flashing can send water down the wall and into the top of the opening. Check these exterior elements before assuming the window has failed.
Ask Master Seal about new window installation in Maryland
Troubleshooting the source of a window leak is not always a simple task. Having an expert resource in the Baltimore area that you can count on to help you address a leaking window and help guide you on possible window replacement can be invaluable. The Master Seal team not only has expertise in all things window-related but also doors, pilasters, and pediments.
