Glass Window Sealed Units Repair

Fog or condensation between the panes of your window? Sometimes the cause is obvious like cracked or broken glass, but the most common cause is that the seal has failed.

Glass Window Sealed Units RepairWhat is a sealed unit and how does it work? A sealed unit (also referred to as a Thermo, Thermal Unit, IG Unit or insulated glazing), is a glazing system that consists of two or more panes of glass with an adhesive spacer separating each pane. To ensure the unit performs, the space between must either be a vacuum or, for better insulation value, be filled with an inert gas such as argon. To ensure the vacuum or gas do not leak, the perimeter of the new unit is sealed with a vulcanizing compound. Needless to say it’s that insulation that helps keep your home warmer in the winter and cooler in the summer!

M&T Glass provides sealed units of the highest caliber. Each and every one them carry the IGMA seal of certification!

Frequently Ask Questions

Should I buy a complete new window or just replace the sealed unit?

The answer to this question is very simple because there are only two real reasons to consider a complete window replacement:

  1. Your existing window is beyond economic repair or, replacement parts are obsolete. Rule of Thumb: If the total you would spend fixing your window is greater than 50% of the cost of a replacement, your window should not be repaired.
  2. You are looking for a performance improvement over your existing windows to make your home more energy efficient or, you are upgrading all windows to enhance the value of your property.

Replacing a sealed unit is significantly less expensive than replacing an entire window!

Can you match my existing sealed unit to the one you are replacing?

In most cases yes! Where the new replacement may not match exactly is if the failed unit has an older or obsolete Low E or reflective coating. The performance of high efficiency & reflective coatings (like Low E and heat mirror for example) has improved significantly over the last few years. This has been achieved through new manufacturing processes and improved coatings. As a result, the replacement may appear to have a variation in the shade or hue. Most people find the difference subtle and are not concerned.

Can’t my old sealed unit just be repaired?

No! Once the seal has been compromised there is no cost effective repair option. Some glass and window repair companies in Ottawa offer a service that drills a hole in the glass and pumps in a mist that lets the immediate condensation dissipate. They then put a vinyl disk or valve over the hole. HOWEVER; they never repair the seal that has failed! Once the vacuum or gas is gone, any insulating properties are gone. How do we know for sure that this does not work? Because we replace them for dissatisfied customers regularly!

Matching also applies to standard and high performance spacers, internal grills, and shapes!

How do I proceed?

Sealed units should be installed by a professional or by someone who is very knowledgeable in window manufacture. While we do offer “cash & carry”, improper installation could lead to weather infiltration, premature unit failure, and poor performance.

We offer:
  • FREE Onsite estimate in the Ottawa area
  • Onsite installation; from taking measurements and ordering your unit, to our technicians installing at your home or business.
  • Shop supply & installation (if your window is removable); bring your window to us and we’ll inspect, measure, and provide you with a quotation. If you go ahead, take your window home and we’ll order your replacement. Bring your window back to us and we’ll install the replacement. Ask about our “while you wait” service!


If you notice fogging, condensation, or poor performance from your insulated glass, it’s time to call the Ottawa glass and window repair specialists at M&T Glass!


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    Your Glass Needs, Our Priority

    M&T Glass Shop is not just a service provider; we are your trusted glass partner. Recap the key points and consider this an invitation to explore our services. Contact us or visit our shop to experience the M&T difference.

    Your EMERGENCY is our EMERGENCY! Our emergency operators and service technicians are here to support you 24 hours a day and 7 days per week! Call us at (613) 745-7158.


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