There are many different bifold door and building terms in the construction industry. For those of us without construction experience, it can be hard to know where to start. To help, we’ve put together a list of the most common terms we use at Diamond Doors when discussing your bifold door. We’ve also included a brief description of the purpose of each material and how it relates to your door.
Helpful hint: If you’re looking for a specific term, use ctrl+f to use your browser’s search bar to look through this page for instances of that word.
If you have questions about a door or building term that’s not on this list, you can contact our office directly by calling us toll-free at (866) 325-7600 or by emailing info@diamonddoors.com. We’re always happy to help.
Anchor Bolts
Anchor bolts are heavy-duty bolts used to secure structural elements to concrete. These bolts come in a variety of styles depending on the needs of the building. They can be installed directly into wet concrete or drilled into hardened concrete. Anchor bolts are used to secure the Diamond Doors self-supporting header system (if included in the door package) to the building’s foundation.
Bolt Height
Bolt height is the distance between the finished floor and the height at which the bolts for bifold door hinges are located on the building. We design your bifold door to be hung at a pre-specified bolt height. This ensures that your door fits snugly into your rough opening, and leaves the appropriate space for your bottom rubber seal.
Brake Motor
Brake motors use an integrated braking system that is engaged when there is no power to the motor. These motors prevent the motor from moving when there is no power to the motor. These are often used for safety applications. Diamond Doors uses brake motors to hold the door securely in place while opened, in the case of a power failure, while operating.
See Also – Brakeless Motor
Brakeless Motor
A brakeless motor is a standard motor that relies on an external force to slow or stop its motion. Brakeless motors are the most common type of motor and probably the kind that you are most familiar with. Diamond Doors uses a brakeless motor for our automatic locking system, where safety isn’t a concern if the power should fail.
See Also – Brake Motor
Cable Safety Factor
For example, our cables have a tensile strength rating of about 4000 lbs. A door that weighs 2000 lbs would come standard with five lift cables, for a total weight rating of 20 000 lbs, which is 10 times higher than the total weight of the door.
Cable safety factor is a measure of the safety provided by the combined strength of all the cables on the door. At Diamond Doors, we use a 10:1 safety factor, which means that we provide ten cables to support your door for every one cable that is technically needed.
In addition to providing additional safety, these extra cables better distribute the weight of the door and increase the lifespan of your door and building. In comparison, many competitors use only a 5:1 safety factor. Please note that we only recommend operating your door when all cables are securely installed.
Center Hinge
The center hinge is the hinge points between the top and bottom sections of the bifold door where it folds as it opens.
Center Trim
The center trim is made from 26 gauge steel that is fastened to the top of the bottom section of the door to prevent moisture infiltration. If you are installing your bifold door on an existing building, Diamond Doors is happy to provide the cladding and trims you need to finish your door. However, for new buildings, we recommend ordering your door cladding and trim from your building supplier for the best colour match.
Clear Opening
Clear opening is the space through which a person or equipment can pass through when the door is fully opened. At Diamond Doors, we aim to maximize the size of your clear opening to provide you with a door that will fit your equipment and plane for many years to come.
See Also – Rough Opening
Column Follower
Column followers are a wind protection option used for steel building applications that follows the inside of the vertical column flange to secure the bottom section of the door against the door frame, especially when positive air pressure is present inside the building.
See Also – Roller Catch
Column Support Angle
Diamond Doors designed column support angles that are installed on the top portion of the door post of wood buildings to prevent bowing and warping from the loads of the door. These column support angles are easily installed and provide excellent structural support to wood framed buildings.
Door Header
A door header is the structural beam placed at the top of the door that distributes the loads above the door frame onto adjacent supports, and supports the weight of the bifold door. The location of the door header is determined by the bolt height of your bifold door.
Your door header should be inspected prior to bifold door installation to ensure structural integrity and strength.
Door Jamb
The door jamb is the parts of the door frame around the top and sides of the door that provide structural support to hang the door. The material used for your door jamb will vary depending on your building type. Please let us know the specifications of your door jamb to ensure that we can provide the necessary mounting hardware for your bifold door.
Drip Trim
The drip trim, usually made from 26 gauge steel, that is fastened to the bottom of the door to provide proper moisture shed. If you are installing your bifold door on an existing building, Diamond Doors is happy to provide the cladding and trims you need to finish your door. However, for new buildings, we recommend ordering your door cladding and trim from your building supplier for the best colour match.
See Also – Center Trim, J Trim
Eave Height
The eave height is the distance from the finished floor to the top of the roof along the sidewall. Knowing the eave height is especially important for sidewall mounted doors, as it limits the bolt height available.
See Also – Haunch Height
End Wall
The end wall runs perpendicular to the building’s ridgeline and rises to meet the building’s peak. Bifold doors are most commonly installed on the end wall of buildings, as the the raised peak maximizes opening height. If your building has an overhang on the end wall, be sure to let our sales team know so that we can appropriately design your door to accommodate the overhang.
See Also – Gable Wall, Ridgeline
Exterior Finishing
Exterior finishing is any material used to cover the exterior of a structure for protective and aesthetic purposes. Different types of exterior finishings include steel cladding, polycarbonate sheeting, wood siding, and vinyl siding. Diamond Doors offers steel cladding as a standard finish for your bifold door. However, we are happy to accommodate any custom finishing options you may desire. You can read more about finishing options for your bifold door on our blog.
Fabric Building
A fabric building is manufactured with a sturdy fabric cover over a metal frame. These buildings are one of the most cost-effective building styles, although the lifespan may vary. Fabric buildings do not have the structural strength necessary to support a bifold door. However, with the Diamond Doors self-supporting header system, it is possible to use a bifold door with your fabric building.
Gable Wall
The gable wall runs perpendicular to the building’s ridgeline and rises to meet the building’s peak. Bifold doors are most commonly installed on the gable wall of buildings, as the the raised peak maximizes opening height. If your building has an overhang on the gable wall, be sure to let our sales team know so that we can appropriately design your door to accommodate the overhang.
Grade Beam
A grade beam is a beam made from reinforced concrete that is placed at or just below grade level to transfer the weight of the structure to the foundation. Diamond Doors provides different mounting hardware for your door depending on whether you have a grade beam to ensure the best and most secure fit for your building.
Haunch Height
Haunch height in a steel building refers to the vertical distance from the finished floor level to the top of the haunch—which is the point where the rafter (roof beam) and column (vertical support) connect, often in a tapered or reinforced section of a steel frame.
See Also – Eave Height
Heel Height
Heel height is the measurement on the outside of the wall, from the top of the wall to the top of the rafter or top chord. The heel height of your building may affect the bolt height of a Diamond door, especially those designed with a square cut or mitre cut corner.
Horizontal Hinge Load
Horizontal hinge load is the horizontal force on a hinge from door weight and movement. In simpler terms, it is the weight of the door pulling the hinges directly away from the building while in the open position. Diamond Doors provides the horizontal hinge load created by your bifold door on your quote sheet to ensure that your building is structurally sound and can withstand the load.
Horizontal Member
The horizontal member is the horizontal HSS tubes of the door frame that provide structural support. Diamond Doors designs each door with the appropriate number of horizontal members to maximize strength and durability, without causing undue strain on your building.
See Also – Vertical Member
Horizontal Split
A horizontal split door is split into two or more sections between the top and bottom sections of the door. This accommodates shipping restrictions. We make every effort to ship your door in one piece. However, if that is not possible, we will ensure that you are aware before delivery. We have also included detailed assembly instructions with your door to simplify the assembly process.
See Also – Vertical Split
HSS Square Tubing
HSS stands for hollow structural section. It is a rectangular, square, or circular steel tube formed in a wide range of sizes. HSS tubing offers rigidity and strength without the weight of a solid steel bar. Using HSS tubing allows Diamond Doors to build a lightweight yet extremely durable door frame.
I Beam
An I beam is a structural member made from structural steel in the shape of an “I” or “H”. I beams are commonly used as structural support in steel buildings, distributing loads and building weight evenly across the structure. I beams are a great option for your door’s vertical columns as they provide a durable and smooth track for your door rollers to glide on.
Inward Force on Roller
The inward force is a force that the door exerts on the rollers, toward the building column, when in the open position. Diamond Doors will provide the inward force on your rollers exerted by your door before you order to ensure that your building can withstand the total force. For wood buildings, the force may require the column support angles to provide additional bracing and structural support.
See Also – Column Support Angle
J Tracks
J Tracks are galvanized steel tracks in a “J” shape that provide a continuous smooth surface for the bifold door rollers to glide on. These tracks are used on wood frame buildings and are installed on the vertical columns of the building. They also hold the door rollers against the door frame to prevent the door from blowing outward when there is positive air pressure inside the building.
J Trim
J Trim is made from 26 gauge steel and fastened to the top and sides of the door frame. It prevents water infiltration and provides an aesthetic finish. For bifold doors on existing buildings, we are happy to provide trim and cladding for your door. For new buildings, we recommend ordering your door cladding and trim from your building supplier for the best colour match.
See Also – Center Trim, Drip Trim
Limit Switch
Limit switches monitor the overall position of another object and use that information to control an electrical circuit. In this way, they control other machinery or equipment. Limit switches ensure that an object doesn’t move past the pre-determined limits. We set the lower limit switch of your bifold door in-factory. Upper limits must be set during installation, as it will vary slightly depending on the finished floor.
LVL, Laminated Veneer Lumber, Laminated Header
LVL is an engineered piece of lumber. It is made from many thin pieces of wood layered together using heat, adhesives, and pressure. LVL is stronger and more durable than solid wood. It also has a higher resistance to warping, twisting, or cracking, which makes it a great choice for door headers.
Miter Cut Corner
A miter cut corner is an angled corner at the top of the bifold door. It maximizes clear opening height without going past the roofline. Diamond Doors provides custom flashing (or a cutlist for your building supplier) to ensure that the edges of your bifold door are tightly sealed and protected from the weather.
See Also – Square Cut Corner
Overload Switch
An overload switch is a safety device that protects electrical components by sensing excessive currents. It trips the electrical circuit when excessive currents are detected. Overload switches protect the Diamond Doors lift motor from unusually large currents. When it senses a large current, it trips the circuit and prevents the motor from running to avoid heat damage to the sensitive electrical components inside the motor.
Peak Height
The peak height is the vertical distance between the finished floor and the highest point of the roof. A building may have multiple peaks depending on its complexity. When providing peak height measurements to Diamond Doors, please provide the peak height of the wall on which your bifold door will be mounted.
See Also – Ridgeline, Gable Wall
Photoelectric Safety Sensors
Photoelectric safety sensors are positioned near the floor on either side of a doorway. They connect via a light beam. When this beam is broken, it signals to a control system and stops the downward operation of the door. Diamond Doors includes photoelectric safety sensors, or photo eyes, on every door to protect people and equipment from damage.
Pre Engineered Steel Building
Each steel component for a pre engineered steel building is manufactured before delivery to the building site. It provides cost savings in its ease of construction and is appreciated for its large interior clear spans and structural strength. Bifold doors offer many advantages for steel buildings, including easy installation, insulation packages, and a maximized clear opening.
Pull
Pull is the outward force on the building header at the door’s top hinges when in the open position. Diamond Doors calculates the outward pull of the door and provides it on your quote sheet. Your building designer will ensure that your building header can handle the pull loads of the door.
See Also – Total Outward Load
Ridgeline
The ridgeline is the horizontal line running the height of the roof where two angled roof planes meet. A building may have multiple ridgelines depending on the complexity of the building’s design.
See Also – Side Wall, End Wall, Gable Wall, Peak Height
Roof Pitch or Roof Slope
The roof pitch or slope is the angle of the roof written as a ratio of the vertical rise compared to the horizontal run. It is generally expressed in inches, as how many inches the roof rises for every 12 inches horizontally. Providing Diamond Doors with the roof pitch or slope of your building allows us to ensure your door fits well on the face of your building.
Roof Plane
The roof plane is the sloping surface of a roof, usually formed by rafters or trusses. A roof generally has at least two planes, and depending on the complexity the roof, may have many more.
See Also – Roof Pitch
Rough Opening
The rough opening is the size of the framed space available before your door and door frame are hung. Measurements are taken from the inside edge of the wall studs, and from the top of the finished floor to the bottom of the door header.
See Also – Clear Opening, Door Header
R-Value
R-value measures the thermal resistance of a material. It can also be stated how well it resists heat transfer. A higher R-value means that the material is a better insulator. It is primarily used to measure the effectiveness of insulation. Diamond Doors offers easy-to-install insulation panels in R12 and R16 values. You can learn more about insulation options for bifold doors on our blog.
See Also – U-Value
Seal Space
The seal space is the space between the finished floor and the bottom of the door’s frame. Leaving an adequate seal space provides room for your foundation to shift without affecting your door. Our bottom rubber seal closes the remaining gap between the door frame and finished floor. Diamond Doors provides a bottom rubber seal that is fastened to the bottom of your bifold door to seal the space between your finished floor and lower door section.
See Also – Weather Seals
Section Height
The section height is the height of the top or bottom section of the bifold door, measured from the outside to the outside of the horizontal members. When you order cladding, insulation, or polycarbonate sheeting from Diamond Doors, we measure the section height of your door to ensure that each piece is cut to length before delivery. This allows you to quickly and easily install it to your door.
Self Tapping Screw
A screw that is designed to create its own threads in the material in which it is being used. Unlike conventional screws, no predrilling is required. Diamond Doors can provide fasteners for your exterior finishing. Our self tapping screws eliminate the need to drill pilots holes in the door frame when installing cladding, insulation, etc.
Side Wall
The side wall is the wall that runs the same direction as the building’s ridgeline. If you are planning to install your bifold door on the side wall of your building, be sure to consider your overhang and eave height as it can limit the opening height of your door.
Single Phase Power
Single phase power is a power supply with two wires (a power supply wire and a neutral wire) that provides alternating current supply. This is the most common type of power supply, most often used for residential buildings and other building projects that don’t require the higher loads of three phase power.
See Also – Wire Gauge, Three Phase Power
Slant Wall Quonset
A slant wall quonset has sloped walls and a almost flat roof. It may be made of wood or steel framing, but is usually finished with steel cladding. In the past, these buildings were cheaper to build than straight wall buildings, but provided more usable space than traditional quonsets. Bifold doors are a great option when retrofitting any type of quonset, as they are installed to the exterior of the building and maximize the clear opening size, especially when paired with the Diamond Doors self-supporting header system.
See Also – Steel Quonset, Wood Arch Rib Quonset
Square Cut Corner
A square cut corner has a square section cut out at the top of the bifold door to accommodate building design elements such as roof overhangs. Diamond Doors provides custom flashing (or a cutlist for your building supplier) to ensure that the edges of your bifold door are tightly sealed and protected from the weather.
See Also – Miter Cut Corner
Steel Quonset
A steel quonset is a prefabricated building made from curved and corrugated metal sheets. Its profile is usually that of a semi-circle. Steel quonsets became very popular in the mid 20th century because they were easily available and provided quick and easy storage. They are most commonly found on farm yards. Bifold doors are a great option when retrofitting any type of quonset, as they are installed to the exterior of the building and maximize the clear opening size, especially when paired with the Diamond Doors self-supporting header system.
See Also – Wood Arch Rib Quonset, Slant Wall Quonset
Structural Load
Structural load is the loads and stresses on a building or structure that includes its own weight, and the weight of other factors. These loads are comprised of two different types of loads; dead loads, which include the stresses from the structure itself, and live loads, which are stresses from any outside factor including people, weather, and the environment. Every door style causes some structural loads on your building. However, these loads can be minimized with proper design and engineering. Overhead and sliding doors generally cause the least amount of load, while hydraulic single panel doors cause the most. Bifold doors are somewhere in the middle.
Stub Column
A stub column is a short, vertical member that doesn’t reach the footing. Rather, it rests on a horizontal beam or slab to transfer building loads. A stub column provides support to long span beams and headers and helps to evenly distribute the load of the building, roof, and door. For bifold doors, stub columns are used to create a flush surface upon which to mount the bifold door.
Three Phase Power
Three phase power is a three wire power supply that provides a steadier supply and higher loads than single phase power. These systems are generally more expensive to install and maintain, which is why they are usually reserved for building projects, like shops and industrial businesses, that require the additional power.
See Also – Wire Gauge, Single Phase Power
Total Outward Load
The total outward load force of the door pulling away from the building (including the difference between the pull on the hinges and push on the rollers). The design of a bifold door means that it pulls away from the building at the top hinges and pushes toward the building at the bottom rollers. The difference between the two forces is the total outward load. Diamond Doors will provide the total outward load force exerted by your door before you order to ensure that the structural design of your building can withstand those loads.
See Also – Pull
U-Value
U-value measures the thermal transmittance of a material or product. In other words, how quickly heat transfers through something. A higher U-value indicates that the material transfer heat more quickly. It is primarily used to measure heat loss due to windows or similar features. Diamond Doors offers polycarbonate sheeting that measures its insulation capabilities as U-Value. Our Therma Vu polycarbonate sheeting has a U-Value similar to that of many double pane windows.
See Also – R-Value
Vertical Hinge Load
Vertical hinge load is the downward force on a hinge from the total weight of the door. This could also be described as the weight of the door pulling downward, toward the ground. Diamond Doors provides the vertical hinge load created by your bifold door on your quote sheet to ensure that your building is structurally sound and can withstand the load.
Vertical Member
Vertical members are the vertical HSS tubes of the door frame that provide structural support. Diamond Doors designs each door with the appropriate number of vertical members to maximize strength and durability, without causing undue strain on your building.
See Also – Horizontal Member
Vertical Split
A vertical split door is split into two or more sections between the right and left sections of the door to accommodate shipping restrictions. We make every effort to ship your door in one piece. However, if that is not possible, we will ensure that you are aware before delivery. We have also included detailed assembly instructions with your door to simplify the assembly process.
See Also – Horizontal Split
Weather Seals
On a bifold door, weather seals are the door components that prevent moisture and wind from slipping into the building between the door and door frame. Diamond Doors provides a weather seal kit that comes standard with every door. A top rubberized seal covers the hinges and seals the connection between the top of the door and the door frame. The bottom rubber seal closes the gap between the finished floor and bottom door section.
See Also – Seal Space
Wire Gauge
Wire gauge is the measure of the thickness or diameter of a wire. A smaller number indicates a larger wire size. A larger wire size carries a higher current and can provide more power over a longer distance than a smaller wire size. With a Diamond door, it is important to follow the required wire size in our installation manual to ensure that your door functions properly. Installing a smaller wire size than is required will cause premature motor failure.
See Also – Single Phase Power, Three Phase Power
Wood Arch Rib Quonset
A wooden arch rib quonset is built from wooden beams with two continuous arches that meet at the peak of the building. They may also be referred to as Quonsets. Wood arch rib quonsets were especially popular for agricultural use in years past, although their popularity has waned. Bifold doors are a great option when retrofitting any type of quonset, as they are installed to the exterior of the building and maximize the clear opening size, especially when paired with the Diamond Doors self-supporting header system.
See Also – Steel Quonset, Slant Wall Quonset
Wood Post Frame
Post frame buildings are built with widely spaced vertical posts buried 4′-8′ underground and horizontal strapping. It has no poured foundation, but relies on these posts to transfer loads and provide structural support to the building. This building style is popular for farm buildings such as cold storage and machine shops. It is also becoming increasingly popular in other industries as well. They are a cost-efficient and easy-to-build structure. Bifold doors are a great choice for post frame buildings, as they maximize the clear opening of your building, are easily insulated, and can be paired with our self-supporting header system when your post frame building needs the additional structural support.
See Also – Wood Stud Frame
Wood Stud Frame
A wood stud frame building is a traditional wood building style that uses closely placed studs on a poured foundation as the frame of the building. Wood stud frame buildings are a conventional choice for houses and residential building, but are also found as farm buildings and hangars. Bifold doors are well suited to wood stud frame buildings, as they offer a larger clear opening than some other door styles and convenient access.
See Also – Wood Post Frame
Y Pusher
A Y pusher is a steel tube with plastic “Y”-shaped pusher ends that provide the initial push from the cables to force the bifold door outward at the center hinge. Depending on the door manufacturer, these components may look different or have a different name. Diamond Doors designs their “Y” pushers with plastic ends to minimize cable wear.
