Big Hangar Roof Questions

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FL Pilot

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FL Pilot
I'm in the very preliminary stages of planning to build a hangar in Florida. Ideally, it will be concrete block, 70' wide by 80' deep. I'm researching self supporting Higher Power or Airside doors, which would be on the 70' wall (as wide as I can fit).

I'm curious if anyone here has built a hangar of similar width?

Being in coastal FL, a hip roof is preferred for wind loads. Has anyone here constructed a hangar with a hip roof (at least) 70' wide? Did you use wood trusses or steel trusses?

I realize it's a big hangar and won't be cheap but I'm only going to do this once. No one ever said "I wish I'd built a smaller hangar."

Please try to keep the replies relevant and objective.

Thanks.
 
70 foot wood trusses are going to be massive. The material cost alone would most likely exceed the cost of steel trusses and their hanging costs. Additionally, it would require some heavy engineering for a block wall to support wood trusses and all the stresses they will impart on the walls. The museum that I used to volunteer at, had an old B-29 hangar with wood trusses. They weighed probably close to 2 tons each, and had lots of 2x16's in them.
 
I’ve seen some pretty neat wide span hangers using tall poles on the walls and cables from their top to support a mid span beam, with guy wires to brace the poles (think a giant capital M when viewed from the front).
 
Id go all steel before I even thought concrete block with hip roof with wood trusses.

IMP's look really nice with added benefit of insulation. CMU sucks as far as r value goes and you'd still need steel to reinforce the opening.
 
FL Pilot said:
I'm curious if anyone here has built a hangar of similar width?
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In view of your weather, I would look at the local hangars that have easily survived multiple ’canes (you’d have to interview the local owners, pilots, fbo managers).
I bet there are also some proven hangar designs & some well-known construction companies in the state that get mentioned several times.
(I don’t think you have to design, or even research designs in this circumstance - rely on the already known & proven.)
 
Our airfield just took a direct hit from Hurricane Milton. All steel hangars survived intact. 5 of the 8 wood frame hangars were destroyed. No comparison.
 
Last company I worked for built a hangar similar in size (100 x 90) for a CL300. Block walls to 12 feet and steel construction. Here is a pic with the plane in it. We decided on a Megadoor hangar door. I think I have more pics during construction and a time laps vid of some of the construction. This is in Ohio.5582400D-AAB1-4309-B6B4-ABFE90188D31.jpeg
 
Ed Haywood said:
Our airfield just took a direct hit from Hurricane Milton. All steel hangars survived intact. 5 of the 8 wood frame hangars were destroyed. No comparison.
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:yeahthat:


My steel T-hangar at KGIF came through Milton just fine. The only sign it had seen a cane was a little sand blown under the door. I heard a few other hangars had their doors come off the tracks and need resetting, but no catastrophic damage.
 
Concrete block . . . as in stacked CMU block? I would think precast wall sections or poured concrete walls would be cheaper than the labor to deal with that. Also, steel trusses on a building span that big would be cheaper than anything you build from wood.
 
SoonerAviator said:
Concrete block . . . as in stacked CMU block? I would think precast wall sections or poured concrete walls would be cheaper than the labor to deal with that. Also, steel trusses on a building span that big would be cheaper than anything you build from wood.
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Most of the time, poured walls are cheaper, but other times they aren't. We poured a tower base and about 100 feet of access road and a parking pad that would have been cheaper to have a parade of mix on site trucks doing the pour, but we were forced to use mix trucks instead. Problem was they could only carry 3 yards per truck due to the slope. 115 yards or so, 3 at a time....ugh....Road access was a killer and that was part of the reason we went with a prefab skidded building for the radio and battery house. We could have done a CMU house for less money, but we were time crunched due to weather when the project finally lit off.
 
Craig said:
Most of the time, poured walls are cheaper, but other times they aren't. We poured a tower base and about 100 feet of access road and a parking pad that would have been cheaper to have a parade of mix on site trucks doing the pour, but we were forced to use mix trucks instead. Problem was they could only carry 3 yards per truck due to the slope. 115 yards or so, 3 at a time....ugh....Road access was a killer and that was part of the reason we went with a prefab skidded building for the radio and battery house. We could have done a CMU house for less money, but we were time crunched due to weather when the project finally lit off.
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I can certainly understand that. It's worth looking into for this application though, even if the cost is the same as CMU construction. Precast wall sections can often be more expensive but they go up quickly as you can have all of the walls up in a few days at most with a crane/hoist.
 
Problem with tilt wall is that it's not designed for a pitched roof, but rather a flat roof. We've had almost 12 million square feet of warehouse space go up within 5 miles of me in the last two years or so, and it's all tilt wall and flat roof. I also haven't seen a joist longer than about 42 feet at any of them.
 
Craig said:
Problem with tilt wall is that it's not designed for a pitched roof, but rather a flat roof. We've had almost 12 million square feet of warehouse space go up within 5 miles of me in the last two years or so, and it's all tilt wall and flat roof. I also haven't seen a joist longer than about 42 feet at any of them.
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I'm not a structural engineer, but I'm not sure that the tilt wall fabrication dictates only a flat-roof. I don't know why they couldn't fasten pitched roofing trusses the same way they do flat roofing trusses as long as it was accounted for in the initial design. Perhaps there's something that happens with panel deflection that makes tilt-wall a poor choice, but I won't know why it would be different from pre-cast or block wall as long as it was designed to be used in that fashion.
 
Tilt wall panels are only connected to the slab and to the roof trusses. The only thing between panels is a caulking material. Occasionally, some designs have welded tie bars between panels, but I've only seen those on multifloor buildings.
 
FL Pilot said:
Take a look at airpark home listings in Florida. Many, if not most, have large hangars constructed of CMU.

Most homes in Florida are CMU as well.
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I understand home built with CMU, and there's nothing wrong with CMU. Cost-wise (at least in the manufacturing projects I've been involved with), the tilt-wall or poured concrete was cheaper. Some of that is complex due to larger volumes and bigger spans. A 70-80' span for a hangar may make the case for not using CMU. Only once the pen meets paper with prices will that be known.
 
I’ve seen many ag buildings with 70’ wood trusses , but if I’m spending a million dollars on a hangar, I’d want poured walls and steels trusses
 
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