Aircraft Hangar Slabs, Aprons and Site Work in Casper, Wyoming

A hangar slab carries a wing-tank-full aircraft on three small tires, a tug and a mechanic with a creeper, and it has to drain, resist fuel and hold a door track within a quarter inch of level. The building is a simple box. The floor, the door and the apron are where the engineering lives. We build the concrete and the site work for hangars at Casper-Natrona County International Airport and for private airstrips across the county.

The airport has two asphalt runways, 3/21 at 10,165 by 150 feet and 8,679 by 150 feet on 8/26, at 5,344 feet of elevation, and it logged 43,126 operations in 2022 with 131 based aircraft. Seventy-one percent of those operations were general aviation, which is the traffic that fills hangars. The airport is also putting up a new 157-foot control tower to replace a 50-foot tower built in 1954. That work tells you the field is investing, and hangar owners will want to build while the ramps are open.

The sections below explain how we handle floors, door foundations, aprons and the unusual rules that come with work beside active runways.

Floor, door track and apron

Hangar floors are reinforced slabs with a smooth finish, laid out with drains that catch fuel and wash water and send them to a separator. The floor usually slopes slightly toward the drains and away from the door, with a thickened edge at the door line. For a heavier aircraft or a maintenance hangar with jacks and lifts, the engineer may increase thickness or add embeds for tie-downs.

Large doors need their own foundation. A bifold or hydraulic door on a clear span of eighty feet or more has a track that must stay level through frost heave and thaw. We build a deep footing or grade beam under the door line, with cast-in-place structural concrete that ties into the slab so the two move together. The apron outside is concrete paving sized for the aircraft weight and fitted with joint sealant that resists jet fuel and de-icing fluid.

What the field is building and who flies from it

The Wyoming State Forestry Division Helibase on airport grounds has become the state's centralized wildland fire operations center, with fueling, parking, maintenance and crew housing next to an air tanker base. The airport business park houses more than 35 businesses ranging from manufacturing to aviation. Together they show the kind of demand the field generates: maintenance bays, storage hangars and ramp space that works year round. Larger maintenance hangars can also be built as tilt-up buildings when the span or fire rating calls for concrete walls.

The airport has moved before. Bar Nunn grew up around the runways of Wardwell Field, the old airport that served until 1952, and the former runways are still visible in the town's street pattern. That history is a reminder that airfield concrete has a long life. Anything poured at the Natrona County airport today should be built to outlast the owner's first lease.

Airport rules, city codes and hangar fire provisions

Building at an airport adds a layer of approvals. The airport owner reviews site plans, heights and crane use, and work near the runways requires coordination on closures, haul routes and equipment height. Public airports are generally owned by a city or county, and a hangar on leased ground follows the lease terms in addition to local permit review. Municipal and public works agencies set many of these rules for county-run fields.

Within the city, commercial permits often need a life-safety plan, engineered building and site plan drawings and Planning and Zoning approval. The city lists the 2024 International Codes and a three foot frost line to top of footing. Hangars add fire suppression, drainage and fuel containment requirements, and the fire code applies. We confirm what the permitting agency and the airport require before we price.

Footings that hold a door and floors that hold a plane

We begin with a subgrade evaluation. Airport soils vary, and frost heave can lift a door track or crack a thin floor. Where soils are poor, we over-excavate, replace with engineered fill and compact to specification. The slab goes down on a clean granular base with a vapor barrier, and the reinforcing is placed on chairs that hold elevation during the pour.

Aprons and taxi connections need careful joint design. Hangar pavement must meet the engineer's thickness and joint requirements, and edges near taxiways must be smooth and free of loose material, because stones and debris are drawn into engines and propellers. We sweep, clean and inspect at the end of each shift near an active surface.

Work beside active runways

Airfield construction has its own rules: marked haul routes, flagged or lighted equipment, radio contact with the tower when crossing active surfaces and strict limits on equipment height. We coordinate our work area with airport operations and follow their escort and badge rules. Crews learn the boundaries and hazard areas before the first load arrives.

Foreign object debris is a safety hazard. Concrete trucks are washed down before leaving the site, loads are covered, and we sweep the haul route. Fuel handling, spill kits and curing compound storage are kept away from the ramp. If a wildlife or weather event changes airport operations, the work stops until we are cleared to resume.

Weather, frost and the flying calendar

The field sits at 5,344 feet, and the pour season is shorter than in lower country. Footings and door foundations go in early in the season so they can cure and settle before the steel and door arrive. The floor is placed after the roof is on, under cover and heat, whenever the calendar allows.

We coordinate with the airport so work does not close the runway on a busy weekend or a fire-season peak. Aircraft owners usually want to move in before winter, which means the apron, the floor and the door must all be complete by fall. We give owners a date for each, and we warn them early when weather puts one at risk.

Tell us the aircraft and the lease

Send the aircraft type, the door width and the lease or parcel. We will return a footing, floor and apron plan, a weather calendar and a price that separates each piece.

Questions Owners Ask

Can a hangar be built as a pre-engineered metal building?

Yes, and many are. The steel frame is simple and fast, and the concrete work is a floor slab, perimeter footings and a door foundation. The anchor bolt layout and erection tolerance that govern any pre-engineered metal building apply here as well.

How do you protect the slab from fuel and de-icing fluids?

We use a dense, well-cured mix with a hard-troweled surface, saw-cut joints that are sealed with a fuel-resistant material and floor drains that connect to an oil separator. The owner may add a coating. We pay attention to curing, because a weak surface soaks up fluids.

Do I need airport approval to build a hangar on leased land?

Almost always. The lease terms set the allowed building size and use, and the airport reviews the site plan, height and construction access. Local building permits are separate. We ask for both sets of requirements before pricing.

Will frost move the hangar door track?

It can if the footing is shallow or the soil is frost-susceptible. We build the door foundation below the frost line the city lists, use free-draining base under the slab edge and keep water away from the footing. The door supplier sets the allowable movement, and we build to it.

Can you pour a hangar floor in winter?

Only inside a closed, heated building with a thawed subgrade. We protect the concrete during curing and keep heaters from blowing hot air across the surface. Winter pours cost more, so we usually recommend finishing the shell in time to place the floor in a warm window.

Related

Ready to talk about your project?