One crucial job your windows perform is keeping the moisture and air out of the wall structure that surrounds them. And the exterior finish at the edges of the window is the so-called point of impact where the unit the wall, and can, therefore, allow a leak or a draft.That is why it is important to understand what finish your new windows will come with.

There are two common types of exterior finishes used in Canada: aluminum cladding (capping) and a brickmould. The price, performance, and longevity of your windows depends greatly on which exterior finish you choose.

Key points:

  • There are two main types of exterior finishes for windows: vinyl brickmould, and aluminum capping.
  • Aluminum capping is used in retrofit installations. Vinyl brickmould is used in full-frame replacements.
  • Windows with vinyl brickmoulds perform better, look more modern, and have fewer problems in the future.

Let’s get into the details.

Aluminum Capping
Aluminum capping or cladding is the way most windows were finished in the past. There is still a wooden brickmould that fastens the window to the wall. The actual exterior side of the wooden brickmould gets covered with bent aluminum capping on the top. The bending and cutting of aluminum is done manually by the window installer and there is always some concern about how clean and seamless it will look.


Why is aluminum capping not as good as a vinyl brickmould?
Esthetic problems aside, there are some performance disadvantages to getting aluminum capping as the finish of choice for your window replacement. We mentioned above that capping is mostly used in retrofit installations today. The problem is that a retrofit replacement doesn’t remove or replace the existing wooden framing or brickmould. Unless your wooden window framing is in a pristine condition and has no moisture damage, aluminum capping may just be a band-aid solution rather than a full fix. Although this isn’t as big of a problem with new construction windows, there is still a reason why capping is not advisable.

Because wood contains moisture, even in new windows, it is possible that your brickmoulds can “sweat.” When put on and sealed, the aluminum capping is supposed to be watertight. But as the sun warms up your windows, inevitably some of the moisture in the wood will begin to surface. Aluminum capping doesn’t allow that moisture to evaporate properly and it can often lead to rotting of the brickmould and spread to the structure around.

Vinyl brickmoulds
There are several reasons why vinyl brickmoulds are a better choice compared to aluminum capping. For starters, it is all about materials. Unlike combination of wood and aluminum, vinyl is much better at withstanding contact with moisture and the elements. Vinyl brickmoulds come in a single piece which reduces maintenance and gives moisture fewer places to get in.

vinyl brickmould
Vinyl brickmoulds are a superior choice for exterior finishes. They don’t deteriorate or rot over time, significantly reducing the chance of moisture penetration in the wall.

Vinyl brickmoulds are usually warranted for the entire duration of your window warranty, which can be as long as twenty-five years. Aluminum cladding on the hand may only last a few years.

This is something that shouldn’t ever happen. A retrofit vinyl window is being replaced just five years after it was installed, because of moisture damage in the wooden frame.

Because vinyl brickmoulds are used in full-frame replacements and new construction windows, it is a more expensive option, but one that probably won’t have to be fixed for many years if done right.

When you are considering local window companies, be sure to find out what the exterior finish of choice is for their installers. Some window companies still finish new vinyl windows with aluminum capping. What’s more important is that you understand how each one works, and make a decision based on your actual needs.

Check out more window replacement articles:
How To Compare Replacement Windows
Find out window replacement prices
Modern Windows Compared: Awning And Casement vs. Slider And Hung

Get a Free Quote On Thermal Windows