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Exterior House Trim Terminology: Everything You Need to Know

exterior house trim terminology

There are some terms within the exterior house trim terminology dictionary that are rather self-explanatory, such as “window trim,” but others such as “fascia” or “batten” are very industry specific. 

It’s important to understand exterior house trim terminology because while the trim materials used for various terms may be the same, the usage and function for each application vary. Therefore, different lengths and thicknesses are required depending on the product application.

Exterior House Trim Terminology

We have put together a list of commonly used terms and their correlating definitions often used in exterior house trim terminology. Whether you’re brushing up on your exterior trim knowledge or you’re new to the industry, this list is a great place to start.

Fascia Board

Fascia is a horizontal board that runs along the roofline, covering up any exposed ends. It’s important to note that fascia serves a functional purpose. It helps protect the roofline from unwanted moisture, which makes it all the more important that your wood fascia boards are preservative-treated. There are a variety of ways to install fascia, but the single step fascia installation with Belco XT® Trim is cost effective and efficient. There are fewer seams involved which means fewer gaps for moisture intrusion. Additionally, you’re installing a beauty cap and structural trim all-in-one.

Belly Band

Belly band may not be top of mind, but it can make or break the aesthetic of a home. Additionally, belly bands are often found in gables. They are often used to separate standard lap or panel siding from shake. Belly bands are also used on larger homes or apartments to serve as a material break between floors.


Battens are used to cover the seam that is created when two siding panels butt up to each other. The batten is then caulked on either edge to keep water from getting behind the panels and causing rot, mildew, and decay issues down the road. They are the first line of defense in a batt and board siding application.

Garage Wrap

Garage wrap is also sometimes known as garage door jambs. These are the trim pieces that cover the rough framed opening for your garage door. Garage wrap covers the rough framing and provide a mounting location for the garage door seal.

Barge Board

A barge board is a board fastened to the ends of the gables to provide extra strength and to cover up exposed ends of timbers in the roof. Barge board is similar to fascia in that it is a straight board that runs along the roofline. However, bargeboards run diagonally. Barge board is meant to tie the roof stringers together across the eve, while also providing a prominent architectural look.

Drip Edge

Drip edge is most commonly a piece of 1×2 or 1×3 material that is fastened at the top of the barge board following the same angle of the gable end. The sole purpose of the drip edge is to make an attachment point for the flashing that runs over the gable while spacing the flashing an inch off the barge board.

Window Trim

Just as it sounds, window trim is the trim that covers the windows. Window trim gives a window dimension and definition. Additionally, it covers the edge between the siding and the window frame, helping to keep out the elements and protect the home.

Window Sill

Window sills protrude from the window trim and siding with a slight slope, typically between 12 and 15 degrees to help rain runoff. This is a beautiful piece of exterior trim that enhances curb appeal, elevating the facade of any home. Additionally, window sill will experience heavy weather exposure from both sun and rain. Therefore, it’s important to choose a strong material that can withstand the elements.

Frieze Board

Frieze board is a type of trim that is typically installed between the top of a home’s siding and the soffit. It’s normally installed flat against the home, but it may be installed at an angle if installed on a gable. A Frieze board may also be used as a decorative, horizontal trim anywhere in or on the home.

Corner Trim

Exterior corner trim is the trim board that wraps around the corners of the home. Corner trim ties the aesthetic of the home together while providing a protective element to exposed edges.

Porch Post

Porch posts serve as necessary structural support for the porch roof.  In addition, they are often built much bigger for design or decorative reasons. Belco XT® Posts are either solid or chaised depending on the need of the builder.


Balusters serve two purposes: they enhance the design and beauty of railings and exteriors and they keep people safe from falling off decks and high outdoor areas. Balusters are made to provide additional support to a handrail or a top rail, supporting the overall structure of a railing.


Rail is a horizontal piece of trim that covers paneling. This is a beautiful piece of trim often seen on porches.

When considering exterior house trim terminology, some of these words are defined within the term such as “corner trim” or “porch post,” but other terms such as “frieze board,” or “belly band,” are more unique. The angle of a trim board matters just as much as its location when thinking about trim terminology. Terminology matters!

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Preservative treated, primed, and available with a combed, brushed, resawn, or smooth face. The real beauty of your home comes to life through a well made trim package.

Preservative treated, primed, and available with a combed or smooth face. These glulam columns are strong, beautiful, and enhance any exterior design. 

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