Clera Windows + Doors Blog

Are your windows air and water tight?

The difference between a properly installed window and one that is performing insufficiently can end up costing a homeowner hundreds of dollars in utility bills. When buying new windows or serving existing ones, making sure they are properly sealed from the onset is imperative. This job is a simple one that will require a minor amount of materials and some time. At the end of the day, you will be glad you took the time to make sure everything is sealed up. If you have noticed unusually high heating and cooling bills, then you should definitely be reading this.

Check your windows, even if they are new

Many homeowners make the mistake of thinking that simply because they bought new windows, their problems will be fixed. While modern energy-efficient windows certainly do much towards insulating your home and keeping your utility bills down, they do need to be inspected after installation to ensure nothing is leaking out. With old and new windows alike, the first thing one should do is examine the frame.

Caulking and weather stripping should be adequately applied to all areas surrounding the window to ensure they are completely sealed up. If you notice moisture or frost buildup at all on the glass, or can see light coming through the frame, then you should make the proper applications. With newer windows, the frame is generally the trouble zone, and with a quick coating of caulking where needed, the job can be complete within a matter of seconds.

The most critical piece of information for making sure your windows are air and water tight is to know their rating for these conditions. The Canada Standards Association rates a window’s air tightness and water resistance capabilities by the A and B standards. An A1 window will likely leak air, while an A3 window will do a much better job at preventing them. Likewise, a B1 window will leak water at rain pressures above a certain point. B7 windows are the highest rated and can withstand substantial wind-rain pressure.

Make sure old materials are stripped clean

A very important tip to keep in mind is to make sure that when replacing your windows, the old material is also completely removed. Sometimes old caulking is left in place, which can lead to leaky spots around the frame where it was not removed. Scraping it clean with a putty knife will leave a smooth surface for the new caulking to be applied, which will possess greater insulation properties.

When applying new caulking, it is important to apply it evenly. Be sure to cut the tip of the caulk gun at the right spot, so that excess run-off will not occur during the application process. Once the layer has been applied to the corners of the window frame, the material should be spread smooth to ensure all of the crevices are being sealed. Improperly applying caulking to a window can leave areas exposed that may be invisible to the naked eye, which can be a hassle when trying to pinpoint the problem of leaks. If you want to do the job right the first time, you can go a step further by removing the trim around the window. The exposed area can be filled with foam insulation, which will expand and fill in any gaps that are inaccessible by external caulking. Once hardened, the foam insulation in addition to the outer layers surrounding the frame will ensure your window is completely sealed from air and water.



  • Avatar for Brad C. from Belleville Brad C. from Belleville says:

    I actually ran into this problem a while back when I purchased my home. I was turned on initially to the fact that the previous owner had installed new energy efficient windows throughout the entire house. I knew this was a costly investment that I could benefit from. Once the 1st winter hit, however, I was surprised at how high are utility bills were. I couldn’t figure it out, until one day I noticed one of the windows had some old caulking on the frame. I decided to check it out and low and behold the contractor did not completely clean out the old stuff before setting some of the new windows in. I have sealed everything up well now, and my bill has dropped a fair amount. This is something everyone should be aware of.

  • Avatar for Richard Norsby- Kingston Richard Norsby- Kingston says:

    What are most windows rated at? I will be checking into this at my house. The last thing I need is some surprise leaks come the rainy season.

  • Avatar for Jack from Burlington Jack from Burlington says:

    It never ceases to amaze me how people can neglect to do something so simple. I think material is a good refresher course for those needing a lesson in home improvement. Anyone can caulk a window, but doing it the right way takes time. I have learned this fact over the years, and I am glad others agree. You don’t need to waste a bunch of money on material if you use it properly. I can attest to the fact that spreading caulking evenly over the surface is very important. If there any gaps present, you will know about it.

  • Avatar for Derek J Derek J says:

    I had this problem a fee years ago when I had new windows installed. A very small amount of caulking was left behind from the old windows and that was causing a little bit of air to seep out. It may not seem like a big deal, but this can really make your utility bill sky rocket! Everybody should check for this there is no reason not to. It takes just a few minutes to check and then you can fix the problem and not have to worry about it ever again.

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