How to Make Sure my Windows Are Installed Correctly 

Poor window installation leads to many issues. Inexperienced or poorly trained installers can leave you with the consequences of air leaks and poor operation. Let’s look at some possible outcomes of incorrectly installed windows.


Windows are a significant investment. In almost every instance, new windows are a positive upgrade. Read our article, Are Replacement Windows a Good Investment?

Most window installations will go well; however, it’s a good idea to check any work done to your home, even as the installations take place.

If you suspect there were mistakes, contact the contractor to ensure the problems are fixed at no extra charge.


A quick list of points to check:


The opening’s measurements must be checked and double-checked.

Careful measurements must be made by the contractor. Replacement windows are not as big as the original windows to allow proper positioning and fit. Approximately 1 inch on all sides allows for the right amount of foam sealant, a crucial aspect of air-tight replacement windows.


Windows must be square, level, and plumb. 

Before the interior trim is installed check that the space between the outside edge of the windows and the frame’s edge is relatively equal all around. Wood shims ensure the replacement windows are set solidly in the opening.


New windows shouldn’t creak.

If you hear squeaking or a popping sound when cranking open your new window, it is likely it has been installed in an opening improperly. Either the opening is too small for the window, or the window has been installed in a slightly twisted way.


Window operation should be smooth.

If your window doesn’t open easily either the sash is misaligned or it’s too big and is squeezed into the opening.



Forest City Window & Door Ltd are window replacement contractors in London, Ontario and the surrounding areas with years of quality window installations and happy clients since 1993.



Are there signs of water damage?

You may not see the water damage right away. Over time you may notice dampness beneath the window and this could be a sign of the window flashing not having been installed correctly. Flashing ensures proper drainage.


You shouldn’t feel any drafts.

If you feel a draft near your window, the foam sealant likely didn’t fill all the gaps. It is best to remove the interior trim and find the source of the air leak around the window. It is easy to add more foam. 


Is there fogging or condensation between double glass panes?

In rare cases during installation accidents happen. The seal between the two panes of glass is damaged and breaks. The inert gas present between double panes of glass escapes and is replaced with water vapour, resulting in the effect of fogging or condensation. 


Caulking must be applied in a professional manner.

Caulk is an essential finish to window and door installations. There should be a clean line of caulk around every window. It should never look patchy, messy, or uneven. Caulking takes a couple of weeks to fully cure so make sure your children do not see it as something to touch.


You should receive a manufacturer’s warranty.

Warranties are provided by the window manufacturer and come with specific installation guidelines that must be followed for the warranty to be valid. If you did not receive one it indicates the contractor did not meet the requirements necessary to pass along a warranty.


Forest City Window & Door Ltd makes your window purchase simple with window manufacturers that are renowned throughout North America; exceptional products that save you money, and are backed with excellent warranties.