7 Common Problems With Windows

condensation problem on a window

While windows can last 20 to 25 years, by the end of their lifetime, they often show various signs of deterioration. However, problems with your windows can be caused by other factors, like the humidity levels of your home. Our Renovation Advisors break down the seven most common window problems and their causes for you!


1. Condensation on windows

Condensation forms when warm, moist air collides with a cold surface. A little condensation on your windows is pretty normal – it may just be a sign that the window is too cold compared to the rest of the house. You can install heating sources directly under windows to avoid this problem.

However, high humidity levels in your home can cause condensation to continuously form. If you notice this happening, check for humidity stains on the walls. High humidity levels need to be taken seriously – not only can they damage your pipes, roof, and exterior walls, but they can also lead to mould. An excessively damp basement can cause high humidity levels, so be sure to check!

Start by checking the humidity level of your home using a hygrometer. If you have an air exchanger, check if it has a dehumidifying function; this will make it regulate humidity levels automatically. However, if high humidity levels are being caused by a leak in the basement, the roof, or the walls, it must be fixed at the source to avoid causing structural issues. This may require major renovations.

The table below shows the recommended humidity levels for outdoor temperatures during winter.

 indoor relative humidity vs outdoor temperature

2. Ice on the bottom of windows

During the winter months, sometimes you’ll see ice form at the bottom of your window. Apart from high humidity levels, this can be caused by poor window installation. To save on costs, some homeowners opt for retrofit installation – it’s less labour intensive and preserves the existing look of a home. However, if the frame isn’t properly resealed, cold air will leak into it and cause ice to form. To avoid this issue, ensure that the frame is in good condition and sealed correctly.

ice on windows

3. Air leaks around windows

Window casings seal the window frame to the house, blocking cold air from entering your home. If you feel a cold air current when you put your hand near the window frame, your window casing might be damaged. Leaky windows cause higher heating bills; your home’s heating energy can escape through them. If your windows are still in good condition, you can address this by correctly caulking your casings.

4. Water leaks under windows

If your window is leaking water, you may have cracks in your caulking joints. This can be caused over time by UV rays and temperature changes, or by poorly applied caulking. For the latter, ensure that there’s enough caulking to cover both the exterior wall and the window frame. The minimum width should be 16 mm (5/8 in), and the thickness should be 12 mm (just shy of 1/2 in).

Water infiltration can also be caused by improper window installation. For example, windows need window flashing, a continuous piece of thin, flexible material that prevents water from getting into a structure. Flashing must also have a 6% slope, extend beyond the siding, have a secondary membrane of sealing, and more!


5. Difficult opening and closing windows

It can be frustrating to deal with stubborn windows. If you’re struggling to open and close your windows, you might have old or damaged window frames or mechanisms. Window frames can warp over time due to frequent use, and some mechanisms, like cranks, can cause damage if used improperly. It’s best to get old windows replaced. If your windows are fairly new, get the ineffective pieces replaced or repaired.

6. Mouldy and rotting wood window frames

Older homes often have wooden window frames. While they’re pretty, they’re also more susceptible to damage from weather changes and insects than PVC or aluminum frames. Their lifespans can be greatly shortened if they’re exposed to a lot of condensation or water leaks. Bubbles and cracks may form in the finish, paint may peel, or even mould may settle. At this stage, a single layer of paint is not enough to protect the wood!


7. Fogged double- or triple-pane windows

While it’s less common, another potential issue is fogging between window panes. This can be caused by a few different things, like broken rubber seals letting moisture in. Aluminum spacers are also more likely to cause fog than PVC spacers – they create thermal bridges, which lead to condensation. In addition, not only do foggy windows obstruct your view, but they also aren’t as well insulated!

Be mindful of companies that claim they can defog your windows. They usually drill holes into the bottom of the window, which decreases its efficiency and essentially turns it into a single-pane window. It’s also a band aid solution. While it improves air flow and reduces fog, it doesn’t address the source of the problem. Instead, change the thermal barrier and opt for low-emission glass. Your windows will be better protected against ultraviolet light and reflect heat.


Repair or replace?

Sometimes repairing the seals, changing the defective mechanism, or reducing your home’s overall humidity levels can fix the issue with your windows. However, if your windows are too old or you’re dealing with mould, repairing is likely a temporary solution. If you have mould, it’s important to find the source of the problem quickly, as mould is bad for your health as well as your home’s.

Replacing inefficient windows is also essential to help reduce your energy consumption, especially if you’re experiencing issues with air infiltration. According to Hydro-Quebec, energy-efficient windows can help you reduce your energy costs by 10%. If you’re thinking of getting them, you may be able to take advantage of the Canada Greener Homes Grant to give your renovations a boost.

Why hire a window installation specialist?

Aluminum, PVChybrid, double or triple-glazed windows, casement… There are tons of decisions to make when choosing a window! A window and door contractor will know which types of windows are best for your home based on the climate of your area. In addition, a contractor familiar with your area will be able to tell you if you need a permit. They will know the requirements for ventilation, security, natural lighting, and even the appearance of doors and windows. A large investment like replacing windows requires careful installation and quality materials.

Get quotes from qualified contractors for your windows

Ready to install new windows? Finding a reliable and high-quality contractor for your project can be stressful, so let us help! Our Renovation Advisors will have up to 3 Verified Contractors submit quotes for your renovation and help you decide which one brings the most value to you. Call us today or fill out our form to get started!