Awning Design

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Custom Covers

Fixed awnings are typically manufactured from Sch.40 galvanized steel, Gatorshield steel or Sch.40 aluminum. These framing materials are cut to size and welded together to form a rigid skeleton to which a fabric cover is manufactured for. A quality structure will be fully welded with each weld primed with a rust inhibitor (for steel frames only) and then fully painted. Although most paints can be hand applied, the most durable finish comes in the form of powder coating or electrostatic paint, which must be applied on site after the frame has been installed. When properly designed, manufactured and with a little TLC, the framework can last thirty years or more. Keep in mind that in areas with high salt corrosion, like near the ocean, a frame built from aluminum is usually your best bet.

 

Once the framework is fabricated, a cover is also custom made to fit the frame. These processes usually happen at the same time, allowing a very short interim (if any) between the frame installation and project completion. Don’t be discouraged if the cover does not fit the first time as this is not uncommon and the fabricator will simply need to tighten up a few areas for the perfect fit!

 

When designed properly, fixed awnings can become an extension of your home adding outdoor living or entertaining space at a fraction of the cost when compared to bricks and mortar. With the addition of fabric curtains, awnings can provide shade from a nasty western exposure or a bug free environment.

The major elements of an awning-system design are:

  • Purpose Style, Configuration, Color Size and Fit
  • Economy Safety: Egress & Fire Stability
  • Anchorage
  • Strength
  • Drainage
  • Graphics Fixed vs. Moveable
traditional-shed1

Traditional Shed

projected-shed1

Projected Shed

half-round

Half Round

bull-nose1

Bull Nose

convex

Convex

gable

Gable

gable-marquee1

Gable Marquee

pyramid

Pyramid

This involves the location, style and strength of connections from the awning or canopy to the building or to its foundations.

 

Proper design of this element assumes a recognition of the amount of force occurring, and the direction in which this force acts, at the connection at the time that the maximum design load occurs on the frame.

 

Most common types of connections involve bolt-through, expansion anchors, wood lag screws and adhesive anchors.

 

Bolt-through connections are preferable, when the are feasible, because the bolt and the nut are manufactured to controlled specifications, and there is a wealth of data on the strength provided by such a connection. Such connections are not generally subject to site questions that are often associated with other types.

 

Expansion anchors are used to fasten awnings to concrete surfaces. They develop their essential strength by pressing hard against the side of the drilled hole in which they are set. This pressure results in high frictional resistance to pullout. While these kinds of anchors have been in successful use for a long time and may be well-manufactured, their use requires more good judgment than the use of a simple bolt-through solution. Obviously, when fastening to concrete surfaces, expansion anchors may be the only practical choice.

 

Wood lag screws are tapered to a point and do not utilize nuts. These are not as sound as bolt-through connections because they are subject to pulling out as the wood surrounding their threads crumbles or chips. Their strength, then, is proportional to the hardness of the wood in which they are embedded. In many awning applications that require fastening to wood framing, bolt-through connections are not possible and wood lag screws may be the best available option.

 

Adhesive anchors have been made available in recent years to provide the awning installer a way to address field situations in which the preceding anchor types are not suitable. Examples of such conditions are veneer brick surfaces and fasteners located close to corners, where the high pressures associated with expansion anchors will raise the risk of being pulled out. Adhesive anchors are bonded directly to the substrate by filling an oversized drilled hole, which contains the threaded fastener, with an epoxy adhesive. This system does not rely on pressure. A certain amount of cure time may be required before the anchor can be loaded.

 

See mounting section to view typical mounting details.

 

Click here for mounting details.

What is the functional objective of the awning – shading, weather protection, identification, or aesthetics?

Most awnings and canopies consist of fabric stretched over and secured to a fixed metal frame that is secured by laces or screws. These frames may be welded, bolted or otherwise connected. Other awnings and canopies that consist of individual fabric panels can be stapled to a groove in the face of an extruded aluminum, fixed-frame element. Still other awnings and canopies consist of rollers and lateral arms that can be retracted manually or automatically.

 

Hoover Architectural has adopted standard awning and canopy styles.

 

It should be noted, however, that the possible combinations of styles, configurations, and colors are limitless.

The size of an awning is determined by its length, width and projection from the building to which it is attached. Other aspects of size include clear height (underneath), rise (pitch) of roof and post or rafter spacing. These features are usually important to those involved in the planning and review process.

 

The fit of an awning is determined by the interfacing of its frame with other connecting structures (most often a building, but frequently the ground or a concrete slab on the ground). In the case of a building, it is important to coordinate the appropriate parts of the awning frame with structural members in the building so that loads are transmitted properly.

The economy most directly affects customers and awning contractors. It is clear that an awning system should not have to meet the same code requirements as a high-rise building. However, in most cases, a code does strictly apply. In rare cases when it is not expressly required, there is still a moral and legal obligation to install an awning that can withstand any foreseeable loads.

 

To develop an economical awning system, the designer must understand how to arrange, size and connect structural members so that the foreseeable loads will be transmitted to its supports while incorporating safety factors, without over-engineering the system.

 

The awning industry and building and code officials should develop a working relationship to better understand each others’ needs. In addition, the industry members’ active involvement in implementing code changes is very important. The objectives should be to assure public safety and to avoid needless, expensive over-design.

 

Sound economical design does not necessarily result in the lowest first cost.

Except in rare cases, this is not a significant issue with modern awning and canopy systems. In most cases, frame materials are noncombustible, and fabrics are flame retardant. However, this point should be ascertained whenever appropriate, such as for enclosed walkway canopies and enclosed patio canopies. The answer is not necessarily to require fire doors and sprinklers for these systems. But the building official does have the right (indeed the obligation) to design systems that provide an open, safe and quick exit to the outside.

The average designer may have a concept of how beams and posts work structurally. But to design a safe structure, one must fully understand stability issues. A structure comprised of simple beams mounted on the top of simple posts is inherently unstable. This means that the structure is susceptible to falling down because of the number, arrangement and method of connection of the members.

 

Common post and beam structures, such as pole barns, are rendered stable by the addition of siding, roofing, “X”- bracing and fixed cantilevered footings.

 

Hoover Canvas Fabric has no in-plane stiffness; therefore, it does not replace, in an awning or canopy, the function that siding or roofing performs as in a pole barn. This in-plane stiffness, which is instrumental to the development of stability, can usually be supplied by triangulation of structural members.

 

The important lesson to learn here is that substituting larger beams or posts for smaller ones doesn’t solve the problem of instability.

After a stable configuration has been established for an awning design frame, members should be chosen for a strength consistent with the amount and type of stress imposed on them. The most common types of stress are tension, compression, bending and shear.

 

A common misconception about awnings is that they are safe as long as they don’t fall down. All code and engineering standards have long required that a safe design use members that are 1.67 to 2 times stronger than the yield strength required to satisfy the actual design stress. The yield strength is the strength at which the material no longer fully recovers to its original shape when the load is removed; the yield strength is usually significantly lower than the ultimate strength. Thus, it can be immediately recognized that a “safe” structure is stressed well below its breaking strength when it is exposed to its maximum design load.

Provisions must be made to drain water off an awning or canopy. Fundamentally, this involves establishing a steep enough pitch, properly spaced bows or rafters, as well as maintaining a taut fabric, so that draining water or melting snow cannot cause the fabric to sag and collect water on the surface. Lack of proper attention to this detail can result in potentially large gravity forces on the frame and anchors.

The overall success of a commercial awning may hinge on the design of its graphics. Local codes and ordinances may dictate the size and other characteristics of this feature.

A fixed awning’s frame cannot be deployed from a stowed position and vice versa. A movable awning can be stowed against the building to which it is attached. The standard lateral arm/retractable awnings and horizontal bow awnings are examples of movable awnings.

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