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Siding Terminology: Your Guide for Understanding Parts of Siding 

19 minutes

Residential home siding plays a crucial role in protecting the exterior of a house, enhancing its aesthetics, and contributing to its overall durability. There are diverse types of siding materials available in the market, each with unique characteristics and components. Understanding the parts of residential home siding is essential for homeowners involved in siding replacement or repair projects.  

By familiarizing yourself with these components, you can gain insight into the different elements that make up a siding system and how they work together to create a functional and visually appealing exterior. In this article, we will explore the common parts of residential home siding, providing a comprehensive overview of their purpose and significance in the overall siding installation. From the main cladding panels to the trim pieces and accessories, let us delve into the world of residential home siding and uncover its constituent components.

Siding Components You Should Know 

Board & Batten 

Board and batten siding is a type of exterior cladding or wall covering that consists of wide boards, known as “boards,” with narrow strips, called “battens,” vertically applied over the joints between the boards. It is a traditional style of siding that has been used for centuries and is known for its rustic and timeless appeal. 

The boards used in board and batten siding are typically wide, flat planks that run horizontally across the wall. These boards are installed with a small gap between them to allow for natural expansion and contraction of the wood. The battens, on the other hand, are narrower strips that are usually placed vertically over the joints between the boards, covering the gaps and adding visual interest to the overall design. 


Backerboard, also known as sheathing, is a structural layer beneath the siding panels. Sheathing is typically made of plywood, oriented strand board (OSB), or foam boards and is installed over the exterior framing of the house. It provides additional strength, rigidity, and a flat surface for the siding to be attached to. 

Sheathing acts as a protective barrier against the elements, reinforcing the structure and helping to prevent moisture infiltration. It also serves as a base for insulation and contributes to the overall energy efficiency of the home. 


A buttlock refers to a specific type of joint or connection between siding panels. It is a crucial feature that helps ensure a secure and weather-resistant siding installation. 

When siding panels are installed horizontally, the buttlock is the interlocking mechanism or overlap where the bottom edge of one panel connects with the top edge of the panel below it. This connection creates a tight and seamless joint that helps prevent water penetration and ensures the overall integrity of the siding system. 

Center Butt 

A center butt typically refers to a joint or connection at the center of a siding panel. It is a term commonly used in the installation of certain types of siding materials.  

When installing vinyl siding, the panels are typically manufactured in long lengths and then cut to fit the desired width of the wall. The center butt is the point where two cut panels meet in the middle of a wall section. 

To create a center butt joint, the installer aligns the cut edges of the two adjacent panels and secures them together using specific techniques or accessories. The joint is typically covered with a piece called a center butt cap or center butt strip, which is designed to fit over the joint, providing a finished and visually seamless appearance. 

Drip Cap 

A drip cap is a trim component utilized to redirect water away from the upper edge of vertical siding, effectively preventing water infiltration behind the siding. This essential trim piece serves as a protective barrier against moisture intrusion. Additionally, in some instances, a drip cap can be employed above windows and doors to redirect and manage water runoff, safeguarding these vulnerable areas from potential water damage. By effectively deflecting water, a drip cap contributes to the overall weather resistance and durability of the siding installation, ensuring a dry and well-protected structure. 


A course refers to a single row of siding installed on a wall. Depending on the type of installation, it can run horizontally from one side to the other or vertically from top to bottom. In a horizontal installation, each course spans the width of the wall, while in a vertical installation, each course extends from the top to the bottom of the wall. Courses play a fundamental role in creating a visually appealing and structurally sound siding system, ensuring consistent alignment and coverage across the entire surface. 


The face refers to the visible or exposed surface of the siding panel. It is the side of the siding visible when installed on a home’s exterior. 

The siding face is the portion designed to be seen and can have various textures, patterns, colors, or finishes, depending on the specific type of siding material. It is the part of the siding that contributes to the structure’s overall aesthetic appearance. 


A T-channel is a type of trim specifically designed to connect the ends of two siding panels. It serves as a seamless transition point, particularly when switching from horizontal siding on a wall to vertical siding on a roof gable. 

A T-channel’s primary purpose is to create a smooth and visually appealing connection where the siding’s orientation changes. One common scenario is when a home has horizontal siding on its walls, but the gable ends feature vertical siding. In such cases, the T-channel is used to seamlessly join the horizontal and vertical siding panels, ensuring a cohesive and attractive appearance. 


The F-channel is a specific type of trim component used in siding installations. It is a piece of trim that is designed to accommodate siding panels at a 90-degree angle to the underlying fastening structure, such as the wall or soffit. 


A J-channel is a widely used and commonly found trim piece in siding installations. Its primary purpose is to create a groove that accommodates the end of a siding panel or soffit panel. J-channels are typically employed around windows, doors, eaves, and soffits. 


The area on a siding panel or piece of trim where the fastening holes are located is commonly referred to as the “fastening flange” or “fastening zone.” This zone is specifically designed to accommodate the attachment of the panel or trim to the underlying structure. 

The fastening flange typically consists of pre-drilled holes or slots where nails, screws, or other fasteners can be inserted. These fasteners secure the siding panel or trim piece to the wall, creating a stable and secure installation. 


Fascia is an important architectural element found on a home’s exterior, particularly along the roofline’s edge. It refers to the long, straight board or panel that is typically mounted horizontally and runs horizontally just below the edge of the roof. 

The fascia board is often positioned perpendicular to the soffit and serves multiple purposes. It provides a smooth and finished appearance to the roofline, covering the ends of the roof rafters or trusses. Additionally, it helps to protect the underlying roof structure from moisture damage by preventing water from infiltrating the roof edges. 


The specific location on a piece of trim or post designed to accept the insertion of a piece of siding is commonly called a “siding channel” or a “siding groove.” These channels or grooves are strategically placed on the trim or post to provide a secure and seamless connection between the siding panels and the trim. 


Trim refers to the assortment of pieces used in siding installations to provide a polished and visually appealing finished edge to siding panels or soffit panels. These trim pieces play a crucial role in enhancing the overall aesthetic quality of the siding system. 

The primary function of trim is to create a clean and professional transition between siding panels or soffit panels and other structural elements, such as windows, doors, corners, and eaves. Trim pieces are carefully designed to cover and conceal the cut edges of the panels, providing a cohesive and refined appearance. 

Trim comes in various shapes and forms, depending on the specific application and siding material. Common types of trim include J-channels, F-channels, corner trims, starter strips, and crown moldings. Each trim piece is uniquely shaped to fit its intended purpose and provide the desired visual effect. 


When a piece of siding has been trimmed to fit a specific size, it may be necessary to create crimps on the remaining panel to ensure a snug fit within the slot in the trim. Crimps are small indentations or folds made on the siding panel to securely lock into place. 

To form crimps, a specialized tool called a snaplock punch is typically used. This tool is designed specifically for creating these indentations, allowing for a tight and secure connection between the trimmed siding panel and the surrounding trim. 


Flashing is a vital component used in siding installations to protect against water infiltration at vulnerable areas, such as joints, seams, and intersections with other building components. It acts as a barrier to direct water away from these susceptible areas, preventing moisture damage and promoting the overall durability of the siding system. 

Flashing is typically made of metal, such as aluminum or galvanized steel, although other materials like PVC or rubberized materials may also be used. It is installed in strategic locations to create a watertight seal and redirect water safely away from the home. 

Furring Strip 

A furring strip is a versatile component typically made of wood, although it can also be made of metal, that is applied to the outer surface of a home. Its primary purpose is to provide a stable surface to which siding can be securely fastened. In addition, furring strips are used to rectify or straighten surfaces that may not be entirely flat. 

Furring strips play a significant role in siding installations. By attaching furring strips to these surfaces, a level and even base are created, allowing for a more seamless and successful siding application. 

Head Flashing 

Head flashing is a crucial component used in siding installations to effectively redirect water away from the top edges of vertically installed siding. It serves as an additional layer of protection against water infiltration and is particularly important in areas where water runoff is common, such as above windows and doors. 

Installed horizontally along the upper edge of the siding, head flashing acts as a barrier that prevents water from seeping behind the siding and causing potential damage to the underlying structure. It is typically made of durable and weather-resistant materials such as metal, such as aluminum, or galvanized steel, to ensure its longevity and effectiveness. 


A gable is the triangular section of a wall or roof formed by the intersection of two sloping roof sections. Its importance stems from several factors. Firstly, gables play a crucial role in ensuring the structural integrity of the home. By distributing the weight of the roof and providing support, gables help maintain stability and transfer loads to the foundation. They also assist in effectively shedding rainwater and snow, preventing accumulation and potential damage to the roof. 

Additionally, gables contribute to ventilation and temperature control within the home. They facilitate the airflow and release of warm air from the attic or upper areas through vents or openings. This ventilation helps regulate temperatures, reduce heat buildup, and prevent moisture-related issues such as condensation and mold growth. 

Gable Vent 

A gable vent is a small opening or vent in the home’s gable wall, typically near the gable’s peak. Gabel vents facilitate the circulation of air within the attic space. The gable vent is often covered with a screen or louvered slats to prevent the entry of pests or debris. 

Frieze Board 

A frieze board is a horizontal trim element that is typically installed along the top of an exterior wall, just below the eave or soffit. It serves both functional and decorative purposes in home design. 

The primary function of a frieze board is to provide a transition and visual separation between the siding or cladding on the lower portion of the wall and the eave or soffit area above. It acts as a horizontal border that adds definition and a finished look to the facade. 


Lap pertains to the specific location where two adjacent pieces of siding boards overlap one another. This overlapping configuration serves a crucial purpose by ensuring the creation of a weather-tight seal. By carefully aligning and securing the siding panels, the lap joint safeguards the house’s interior from external elements such as moisture, wind, and debris. 

The concept of lapping siding boards is a fundamental aspect of siding installation. It involves positioning each subsequent board in a way that allows it to partially cover the board beneath it. This intentional overlap adds an aesthetic appeal to the house’s exterior and plays a vital role in maintaining the structural integrity and protection of the home. 


In situations where a piece of siding requires trimming due to size constraints, the subsequent step involves forming lugs on the remaining panel using a snaplock punch. These lugs play a crucial role in facilitating a secure and snug fit of the trimmed siding into the designated trim slot. 

When a siding panel is trimmed, it often results in the removal of a portion that would typically interlock or connect with adjacent panels. To compensate for this alteration and ensure proper installation, lugs are created on the remaining panel. This is achieved by utilizing a specialized tool called a snaplock punch, specifically designed for this purpose. 


Achieving an aesthetically pleasing and structurally sound joint between two panels involves a technique where each end is cut at a precise 45-degree angle. When these angled ends are brought together, they seamlessly form a perfect 90-degree angle, resulting in an elegant and visually harmonious connection. 

By employing this technique, the cut ends of the panels meet at a diagonal, allowing them to interlock flawlessly. The precision of the 45-degree angle ensures a tight and seamless fit, leaving no visible gaps or irregularities. This meticulous joinery method not only enhances the overall appearance of the panels but also contributes to the overall integrity of the installation. 

Nailing Hem 

The nailing hem refers to a specific area found on a siding panel or piece of trim, precisely designated to accommodate the fastening holes required for secure installation. This specialized region serves as a crucial component in the attachment process, allowing for secure and reliable affixing of the siding or trim to the underlying structure. 

Positioned along the edges or corners of the siding panel or trim piece, the nailing hem offers a designated space where nails, screws, or other fasteners can be driven in to securely hold the material in place. The strategically placed fastening holes within the nailing hem ensure optimal stability and prevent potential damage to the material during installation.  

Outside Corner Trim 

The outside corner trim is a specialized component that serves the purpose of joining siding courses at a precise 90-degree angle on the outer corners of a building. This trim piece is designed to create a clean and visually appealing transition between adjacent siding panels, providing a seamless and professional finish to the structure’s exterior. 

Installed along the outer corners of the building, the outside corner trim plays a crucial role in enhancing both the aesthetic and functional aspects of the siding installation. It acts as a protective barrier, shielding the vulnerable edges of the siding panels from potential damage caused by impacts, moisture, or weathering. Additionally, the corner trim helps to maintain the structural integrity of the siding by providing reinforcement and support at these vulnerable corners. 


The concept of “plumb” revolves around the use of a plumb line to determine whether a horizontal surface is precisely perpendicular or at a 90-degree angle with the ground. This simple yet invaluable tool helps ensure the accurate alignment and levelness of structures and surfaces, enabling a precise and visually pleasing result. 

A plumb line consists of a weighted string or cord with a weight at the end. When suspended from a fixed point, such as a reference point on a structure or a temporary guide, the plumb line reveals the true vertical or “plumb” direction. By observing the alignment of the string with respect to the ground or a predetermined reference point, one can ascertain if the horizontal surface is perfectly perpendicular. 

Positive Lock 

The positive lock is a mechanical mechanism designed to facilitate the installation of panels by enabling smooth sliding back and forth. Its primary purpose is to assist in the installation process while ensuring that the panels remain securely attached once the installation is complete. 

The positive lock mechanism serves as a valuable aid during panel installation, particularly in siding or modular systems where panels must be aligned and fitted together seamlessly. By incorporating a positive lock feature, the panels can be easily maneuvered into position, allowing for precise adjustments and alignment during the installation process. This ensures a more efficient and accurate installation, saving time and effort for the installer. 


The term “profile” is commonly used to describe the siding’s aesthetic look and shape. It refers to the specific design features, contours, and dimensions that give the siding its distinctive appearance. 


A soffit is a term used in architecture and construction to refer to the underside of a building element located on the roof’s eaves, extending horizontally from the exterior wall to the edge of the roofline. The soffit provides a finished look to the underside of the roof overhang and is ventilated to promote air circulation in the attic or roof space. 


In the context of siding, a square is a standard unit of measurement used to determine the amount of material required to cover a specific area. One square is equivalent to 100 square feet (10 feet by 10 feet) of surface area. It serves as a convenient way to estimate and calculate the quantity of siding materials needed for a particular project. 

The term “square” originated from the notion of covering a one-story building with a roof that has an area of 100 square feet. This measurement convention has carried over to siding installations, where contractors and suppliers use squares to determine the amount of siding panels or shingles required to cover a given exterior surface. 


A shingle on siding refers to a compact wooden piece that has been cut on both sides and utilized as an exterior covering for a building. 


Strapping, also known as a “furring strip,” refers to a strip of wood or metal that is affixed to a surface, providing installers with a stable base to secure other materials. Its primary function is to offer a nailing surface, ensuring the secure attachment of various elements during construction or renovation projects. Additionally, strapping can be employed to rectify uneven or out-of-plumb surfaces, enhancing the overall stability and appearance of the finished structure. 


Scoring refers to the process of using a utility knife or a similar tool to create a deliberate, shallow cut or groove on a panel or material. The purpose of scoring is to weaken the material along the scored line, allowing for a clean and controlled break or snap along that line. 

Starter Strip 

A starter strip refers to the initial strip, or board that is affixed to the bottom of a wall or surface, providing a secure base for the attachment of the first course of siding or other cladding materials. It serves as a foundational element that facilitates the proper installation and alignment of subsequent siding courses. 

The primary purpose of the starter strip is to establish a level and sturdy starting point for the siding installation. It creates a straight and even line, ensuring that the first row of siding is properly aligned and securely fastened. By attaching the starter strip to the bottom of the wall, installers have a reliable surface to which the initial course of siding can be securely anchored. 

Tongue & Groove 

Tongue and groove is a method of interlocking used to join two pieces of siding together. It involves the insertion of a protruding “tongue” into a corresponding “groove” on another piece of siding, creating a secure and seamless connection between the two pieces. 

When utilizing the tongue and groove technique, one edge of a siding panel features a tongue, which is a narrow, elongated projection extending along the length of the board. The adjacent siding panel is designed with a groove, a matching channel or slot that runs parallel to the edge. During installation, the tongue of one panel is inserted into the groove of the adjacent panel, creating a snug and interlocked fit. 

Elevate Your Home’s Beauty and Durability with DaBella and James Hardie! 

When it comes to residential siding, DaBella is the name you can trust. We proudly offer James Hardie fiber cement siding products, renowned for their exceptional durability, innovative ColorPlus™ technology, and industry-leading warranties. 

With James Hardie fiber cement siding, your home’s exterior will be transformed into a fortress of strength. Engineered to withstand even the harshest weather conditions, this siding solution resists rot, pests, and fire, ensuring long-lasting protection for your home. 

Not only does James Hardie siding provide unmatched durability, but it also brings unparalleled beauty. James Hardie ColorPlus technology offers a wide range of fade-resistant colors that will keep your home looking vibrant and fresh for years to come. Say goodbye to fading colors and hello to a stunning and enduring exterior. See some of our exclusive James Hardie colors.

When you choose DaBella, you are choosing expertise and craftsmanship. Our skilled professionals are committed to delivering flawless installations, ensuring every detail is taken care of. We take pride in providing a seamless and stress-free experience, making your siding replacement project a breeze. 

Don’t wait any longer to enhance the beauty and durability of your home. Contact DaBella today at 844-DaBella for a consultation and let us show you how James Hardie fiber cement siding can transform your home’s exterior.  

Steven Shortridge

District Manager

Portland, OR

Learn more about Steven