Blog > Category > Posted: 2019-Aug-23, Updated: 2023-Apr-25

Trim, capping, cladding, brickmould, flushmount & nail fins

Trim, capping, cladding, brickmold, flushmount & nail fins
There are many ways of finishing the exterior of a window or door and it's a good idea to understand what your finishing options are. It could make a huge difference in how satisfied you will be with the final outcome.


The frame that goes around a freshly installed window is often referred to as trim, capping, or brickmould.

trim exterior.svg

This blog entry covers some of the exterior finishing terminologies and provides some visual comparisons that we hope will help you ensure you are getting the framing results you’re expecting.


Capping refers to the application of putting a framed material along the outside edge of a window where the window meets the wall frame. Historically, the process of capping was created to cover existing ageing wooden window trim, thereby freshening up the look of the window as a whole. Today capping (also referred to as cladding) is a process of finishing up the installation or replacement of windows and there are lots of ways to do this.


Ask your window specialist which option best suits your specific installation.


A Brickmould is a window trim finishing option in which the trim is attached to the outside of a window and is designed to cover the gap between the window frame and the exterior of the home (vinyl siding, brick, stucco, wood…). Various widths and styles of Brickmoulds are available to accommodate every installation application. Brickmoulds will increase the cost of your window, and because they are larger than the window frame, they must be installed from the outside rather than the inside, making installations more difficult, especially for second and third-story windows requirements.


These extrusions will last the lifetime of the window, they cover rough openings between the window frame and wall and add visual interest to the completed window.

Ask your window expert which option best suits your specific installation.

Flush mount

A flush mount window option is often used in a home that has vinyl j- channel window finishing application (vinyl siding) or where windows are mounted inside a brick, stone or other material frame. It is an option intended not to have any trim application at all, however, it often entails the use of a very thin outer frame, secured by caulking and covering the thin gap between the vinyl j-channel or the brick and the window edge.

Flush Mount

If you choose to do a flush mount with a j-channel, remember, to finish up and seal the window gap, caulking will need to be applied, and if your window is a different colour than your vinyl, then the contrast between the caulking and your window may be as cleanly finished than you would expect.

Ask your window sales expert which option best suits your specific installation.

Nail Fins

Nail fins are semi-flexible strips of window material that are used to attach a window frame to a stud opening. This window application is typically used in new construction and allows for a nice tight waterproof fit of vinyl or wood siding.

nail fin

Ask your contractor which option best suits your specific installation.


Although technically cladding and capping are two separate terms, they are often confused by non-professionals. Cladding is typically a material that is put over another material to either, strengthen, change the properties of or beautify a window product.

There are several places where window cladding can be used. Take for example a regular PVC (vinyl) window, many companies have evolved their technology to replace vinyl channelled sills with wood, covered with vinyl (vinyl cladding) because wood is a very good temperature insulator and because vinyl is very easy to clean and maintain.

vinyl clad sill

And here’s where it sometimes gets confusing. Windows can also be produced as a cladding option, vinyl cladding (wooden windows with an exterior vinyl outer shell) and Aluminum cladding (wooden windows with an exterior aluminium outer shell). Both cladding options typically are designed to improve the durability and longevity of the window while allowing the interior to offer the highly-desirable look of real wood.

Always ask questions, never assume, and if you are still not sure, ask again.

Related topics

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Infographic - What's there to know about windows

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Infographic - Window installation - DIY vs Professional

e-book - Almost everything to know about windows

Diagram - Anatomy of a window (exterior view)

Need more information?

If you would like to know more about exterior window finishing options, we'd love to hear from you. Better still, why not schedule an appointment and come in and see our products for yourself?

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