Anchoring Systems

Anchoring Systems

Unlike traditional buildings, an air dome anchoring foundation is designed to handle the uplift and horizontal forces acting on the dome.  The dome fabric is held up by pressurized air, which also creates lift on the dome itself, creating the need for the dome to be weighed down. How are Broadwell Air Domes anchored? What are your options?

Anchoring Options

When wind blows against the dome, it creates more force that needs to be counteracted by the weight or anchoring forces of the foundation that keep the dome in place. Building codes typically require the dome to achieve the ability to withstand a specified wind load. Our domes can be engineered to withstand up to 150+mph.

Our expert engineers and designers determine the anchoring force required per linear foot of your perimeter to achieve the required. We then design your dome anchoring foundation to achieve these force loads. We have many different anchoring options and can even design a custom anchoring solution to meet your needs. Our precise calculations and anchoring designs create extremely secure dome foundations that minimize air leakage, thus requiring less energy to keep your dome inflated, heated and/or cooled.

*Question to Consider: What kind of soil/material will be underneath your dome? Professional geotechnical soil testing may be needed to determine the load bearing capacity of your soil*


Broadwell Grade Beam Concrete Footing

Most often used for permanent applications, many Broadwell domes have anchoring systems that consist of a grade beam concrete footing with embedded bolts, to which the dome is attached using steel angle irons (see picture to the right of angle irons). The width and depth of the footing will depend on the anchoring forces required for your specific dome. Some footings can be 2' wide and 4' deep, others may be 3' wide and 7' deep. In areas where snow removal around the dome will be needed or there is significant rainfall, this footing is raised 6" off the ground for extra protection.

Earth Anchors

Earth anchors come in various designs, but for Broadwell Air Domes they are typically a steel arrowhead connected to a reinforced cable that is driven as deep as 5' into the ground. This cable is then anchored into a smaller concrete footing, or to an angle iron. Knowing soil composition is necessary with this option, as the anchoring load of each earth anchor depends on the type of soil it is being driven into. Obtaining a geotechnical report from professional soil testing may be required. For example, one of our earth anchors may have a anchoring capacity load of 5,000 lbs when anchored into hardpan/asphalt. The same earth anchor may only have an anchoring capacity load of 600 lbs when anchored into loose, fine uncompacted sand.


Sand or Water Ballast System

This option is typically used for mobile or temporary dome applications. Your dome would be weighed down with large ballast bags filled with the required amount of sand or gravel. Our engineers have also designed an anchoring system with a large reinforced tube or bladder of water around the perimeter of the dome. These can be used for smaller domes (typically below 35,000 square feet).

Cement Blocks

This option is also typically used for mobile or temporary dome applications. Cement blocks are used on the outside perimeter of the dome to weigh it down, or some of our clients have created custom cement blocks with bolts embedded to them, to which the dome is attached. Some of our mobile "event dome" clients have used cement "bin blocks" to weigh the dome down. These are relatively inexpensive to rent or purchase in many areas.

Steel Plated Box Filled with Gravel

This custom anchoring system was developed by Broadwell engineers for a client who owned a gravel pit and wanted to use gravel in their anchoring system.


The goal of an air dome anchoring system is to create a consistent and strong anchoring force load. As shown above, this can be achieved in a variety of ways. Our team of 50+ employed engineers are the most innovative in the industry. We are constantly developing new and innovative ways to anchor our domes.

Dome Components


Our domes are comprised of various mechanical elements. Click on the following links to learn more about what pieces make up our domes: