Good morning all,
I have tried searches for the above with little success so far, so thought I would ask the question.
Does anyone use a quonset for their 170? I have purchased a 45ft. with 22 ft arch at centre point and all measurements indicated I would have enough room, so it's delivered and getting ready to start.
We are fortunate up here in Canada that airports fall under Federal jurisdiction so local building inspectors/ codes are not required.
Of course the building is designed/stamped for use in Ontario with appropriate snow load for our area considered, and all local construction codes will be used as if local authorities were involved.
I guess the reason for the post is to see if anyone out there in 170 land has gone through a construction? is there any pit falls to watch for? any tips that may save me some-lots of grief?
I have jumped on U-Tube and there are a few videos on putting them up, but just wanted to check on this forum as well to see if there is something that might help.
Thanks in advance!
Pat
Quonset Hut hanger
Moderators: GAHorn, Karl Towle, Bruce Fenstermacher
Re: Quonset Hut hanger
I have a 50X50 hangar that is 20 ft high in the middle. I put it up in 1998. The directions for my building described 2 different methods to anchor the building. The first was to buy plates that would fasten to the concrete and then the metal arches would fasten to that. The second was to mold channels 4 in deep by 9 in wide in the stemwall, set the edges of the arches in the channels and pour mortor into the channels to anchor the building. The second was recommended by the seller so that is what I did. That method has worked well so far.
The directions also described putting a large number of rebar in the stemwall and the floor. The contractor that poured the concrete said I didn't need all that rebar so we only put it in the stemwall. That saved a lot of money and has also worked out well. He poured the flour in 4 parts and so far there is only one hairline crack in one of the sections.
The directions described assembling the arches on the ground and then raising them into place with ropes pulled by guys standing on scaffolds. That did not work at all. The arches are too long and heavy. One of the guys at our airstrip came to the rescue. He had erected one of these buildings and he had a sign crane that could pick up loads like the arches. He had also made a device to hook onto the long arches to stand them up. The device was a piece of 2 inch pipe about 15 feet long with chains attached to the ends. He welded nuts to the ends of the chains so we could put bolts through holes in the arches to attach the arches to the chains. Then he had welded an eye in the center to hook the cable from the crane.
We assembled the arches on the grass next to the concrete and used the crane to stand them up. Two guys were needed, one on each end of the arch to keep the arch from bending or kinking. The first two arches were the trickiest. We stood them up and lashed them to the scaffold. Don't try this in winds over 10 mph. Then we started raising each arch into place and putting bolts into the seams. There were 7 men working on it. Two on the center scaffold, two at each end with step ladders, and the crane operator. We didn't put all the bolts in, just enough to hold it together and we didn't tighten the bolts so it could squirm a bit. After the first 4 we were able to put up an arch in about 30 minutes. The end walls took about a day each. It took another 2 days to put all the bolts in and tighten them.
One mistake I made was not deciding what kind of door I was going to install. At first I was going to use a bifold door, but later changed to a stack door. I chose the stack door because it was cheaper, it even included the siding, and it didn't require so much structure on the building to hold it up or an electric motor to open it. The door rests on a rail mounted on the floor and it folds when open like french closet doors. If I had decided on the stack door when we were pouring the concrete, we could have counter sunk the rail the door sits on. As it is the rail sits on top of the concrete floor and makes it a little difficult to roll the airplane in and out of the building.
I wish I had insulated the building, but that seemed really expensive at the time.
I hope this is the kind of input you are looking for.
The directions also described putting a large number of rebar in the stemwall and the floor. The contractor that poured the concrete said I didn't need all that rebar so we only put it in the stemwall. That saved a lot of money and has also worked out well. He poured the flour in 4 parts and so far there is only one hairline crack in one of the sections.
The directions described assembling the arches on the ground and then raising them into place with ropes pulled by guys standing on scaffolds. That did not work at all. The arches are too long and heavy. One of the guys at our airstrip came to the rescue. He had erected one of these buildings and he had a sign crane that could pick up loads like the arches. He had also made a device to hook onto the long arches to stand them up. The device was a piece of 2 inch pipe about 15 feet long with chains attached to the ends. He welded nuts to the ends of the chains so we could put bolts through holes in the arches to attach the arches to the chains. Then he had welded an eye in the center to hook the cable from the crane.
We assembled the arches on the grass next to the concrete and used the crane to stand them up. Two guys were needed, one on each end of the arch to keep the arch from bending or kinking. The first two arches were the trickiest. We stood them up and lashed them to the scaffold. Don't try this in winds over 10 mph. Then we started raising each arch into place and putting bolts into the seams. There were 7 men working on it. Two on the center scaffold, two at each end with step ladders, and the crane operator. We didn't put all the bolts in, just enough to hold it together and we didn't tighten the bolts so it could squirm a bit. After the first 4 we were able to put up an arch in about 30 minutes. The end walls took about a day each. It took another 2 days to put all the bolts in and tighten them.
One mistake I made was not deciding what kind of door I was going to install. At first I was going to use a bifold door, but later changed to a stack door. I chose the stack door because it was cheaper, it even included the siding, and it didn't require so much structure on the building to hold it up or an electric motor to open it. The door rests on a rail mounted on the floor and it folds when open like french closet doors. If I had decided on the stack door when we were pouring the concrete, we could have counter sunk the rail the door sits on. As it is the rail sits on top of the concrete floor and makes it a little difficult to roll the airplane in and out of the building.
I wish I had insulated the building, but that seemed really expensive at the time.
I hope this is the kind of input you are looking for.
Re: Quonset Hut hanger
I would put rebar in/throughout the floor/foundation. Concrete is very good in compression...very poor in tension. Steel is very poor in compression....very good in tension. They complement each other for the purpose.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
Re: Quonset Hut hanger
This is exactly what I was hoping for!
My plans as well demand re bar at 18" centres, and through the floor connecting the 2 side walls.
I am not planning on a cement floor, so that should help with cost.
George, I understand your point about the combined strength of using re bar and cement together.
Very helpful, thanks,
Pat
My plans as well demand re bar at 18" centres, and through the floor connecting the 2 side walls.
I am not planning on a cement floor, so that should help with cost.
George, I understand your point about the combined strength of using re bar and cement together.
Very helpful, thanks,
Pat
Re: Quonset Hut hanger
It looks like you are not putting in endwalls or a concrete floor. Are you going to run the rebar under a dirt floor or maybe an asphalt floor?
I know where George is coming from regarding rebar in the concrete floor and I was skeptical when the contractor told me that it was just unneeded extra expense. His opinion was that the loads I planned were very light. He was 68 at the time and had been in the concrete business for 50 years so I bowed to his experience. Since I put in end walls, we ran stemwall on all four sides with rebar. He said that was a must. The channels were molded into the stemwall so none of the building weight is supported by the floor.
It was clear from the directions that the building was designed for very heavy loads like grain storage. In that case the floor would need a lot of rebar. So far I have an airplane, three cars and an Airstream trailer and one hairline crack that is barely visible.
One thing that surprised me was the compact size of the building when it came off the truck. It was on 3 shipping palets with five 90 pound buckets of bolts and nuts. The building is also very light since it doesn't have any supporting beams. The directions had me fabricate some clips to fasten the bottom of the building to the stemwall temporarily until the mortar could be poured. This seemed really mickey mouse to me and then the weather forcast called for up to 60 mph winds the next day. I could envision the thing flying off and landing on someones house. The guy with the crane parked a dump truck on each side of the building (only the arches were up) and we strung cables over the top in hopes that would hold it down. Luckily the weather guys were wrong and the wind never exceeded 30. I got busy then putting in the end walls and the mortar.
This building has aluminum in its coating, not just straight galvanized. It is still just as bright and shiney as the day we put up the arches. It kept me busy retightening some of the bolts because of leaks for several months. One way to reach some the highest bolts is to put a square end on a joint of conduit (the nuts are square). After a little practice you can stab the conduit onto a nut and snug it a bit more.
I know where George is coming from regarding rebar in the concrete floor and I was skeptical when the contractor told me that it was just unneeded extra expense. His opinion was that the loads I planned were very light. He was 68 at the time and had been in the concrete business for 50 years so I bowed to his experience. Since I put in end walls, we ran stemwall on all four sides with rebar. He said that was a must. The channels were molded into the stemwall so none of the building weight is supported by the floor.
It was clear from the directions that the building was designed for very heavy loads like grain storage. In that case the floor would need a lot of rebar. So far I have an airplane, three cars and an Airstream trailer and one hairline crack that is barely visible.
One thing that surprised me was the compact size of the building when it came off the truck. It was on 3 shipping palets with five 90 pound buckets of bolts and nuts. The building is also very light since it doesn't have any supporting beams. The directions had me fabricate some clips to fasten the bottom of the building to the stemwall temporarily until the mortar could be poured. This seemed really mickey mouse to me and then the weather forcast called for up to 60 mph winds the next day. I could envision the thing flying off and landing on someones house. The guy with the crane parked a dump truck on each side of the building (only the arches were up) and we strung cables over the top in hopes that would hold it down. Luckily the weather guys were wrong and the wind never exceeded 30. I got busy then putting in the end walls and the mortar.
This building has aluminum in its coating, not just straight galvanized. It is still just as bright and shiney as the day we put up the arches. It kept me busy retightening some of the bolts because of leaks for several months. One way to reach some the highest bolts is to put a square end on a joint of conduit (the nuts are square). After a little practice you can stab the conduit onto a nut and snug it a bit more.
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marathonrunner
- Posts: 449
- Joined: Mon Dec 13, 2010 3:49 am
Re: Quonset Hut hanger
Just an aside, having been to China and parts of Asia, they don't like rebar and it shows when they come down in a very spectacular fashion. Rebar is the way to go.
It's not done till it's overdone
Re: Quonset Hut hanger
Great input!
For sure I am using re bar and as much as the pros think I need. I am considering putting up a low hip wall ( no trough) across the back as I hope to eventually close it in, and maybe extending the corners at the front inward for about 6 feet or so from each corner that will help to give the side walls some more rigidity. Not sure if this will help or just add expense.
We have a quonset hanger with just a compacted gravel floor that has stood the test of time for well over 30 years and going.
Hard to tell if there is re bar under the gravel and the guy that build it has passed so no one at our field has knowledge of construction --just always been there!
I too was surprised when the truck arrived to deliver my building-- that's it? 2 skids and 3 pails?
Now to round up my posse to help-- probably the same all over-- I'd like to help this weekend, but my wife says I have to go...
I'm busy then.... but any other time I could have helped, sorry!
You should have let me know....
Oh well looking forward to getting my beloved 170B in out of the weather--and snow--
For sure I am using re bar and as much as the pros think I need. I am considering putting up a low hip wall ( no trough) across the back as I hope to eventually close it in, and maybe extending the corners at the front inward for about 6 feet or so from each corner that will help to give the side walls some more rigidity. Not sure if this will help or just add expense.
We have a quonset hanger with just a compacted gravel floor that has stood the test of time for well over 30 years and going.
Hard to tell if there is re bar under the gravel and the guy that build it has passed so no one at our field has knowledge of construction --just always been there!
I too was surprised when the truck arrived to deliver my building-- that's it? 2 skids and 3 pails?
Now to round up my posse to help-- probably the same all over-- I'd like to help this weekend, but my wife says I have to go...
I'm busy then.... but any other time I could have helped, sorry!
You should have let me know....
Oh well looking forward to getting my beloved 170B in out of the weather--and snow--
Re: Quonset Hut hanger
Another consideration not widely known is the "recipie" for the concrete mix. Ordinary walkways typically have a 4-sack mix...while house slabs are typically "5-1/2-sack" mix....referring to the amount of portland in the mix to achieve a 3,000 lb or 4,000 lbs etc., breaking strength. Most experienced engineers I've visited with require a 6-sack mix or greater for aircraft hangars. Commercial projects typically specify 7-sack mix for hangar foundations.
The amount of air entrained in the mix, whether or not retardant is required (due to weather on the days of the pour) etc are reasons to consult the engineers and/or ready-mix folks. There's more to concrete than simply mixing cement and water.
Pictures! Pictures!
The amount of air entrained in the mix, whether or not retardant is required (due to weather on the days of the pour) etc are reasons to consult the engineers and/or ready-mix folks. There's more to concrete than simply mixing cement and water.
Pictures! Pictures!
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
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hilltop170
- Posts: 3481
- Joined: Sat May 06, 2006 6:05 pm
Re: Quonset Hut hanger
Another thing to consider in a clear-span building such as your's is how high will your stem wall be? You might decide the stem walls need to be three or four feet high to give more wing clearance inside the hangar.
If it is very high, say over 1 foot, the downward load on the hangar due to its weight and any other loads such as wind or snow will generate a "kick-out" load on the stem wall. To simplify, consider the hangar finished and sitting on a smooth slick surface. If you push down on the apex of the building, the bottom edges of the building will try to move outward under the load. The stem wall is there to react that kick-out load.
If the stem wall is high, the junction between the hangar and the stem wall will act as a hinge and the top of the stem wall will want to rotate outward from the hangar. So the stem wall must be designed to react that load and not move.
If the stem wall is low, it must also be designed so that the kick-out load will not push the entire wall outward under load.
Commonly, the kick-out loads are reacted by tension beams under the floor tied into the stem wall so any kick-out loads just cause tension in the beams and do not allow the stem wall to move.
It is my opinion it would be money well spent to hire an engineer to design your stem wall specifically for your location taking into consideration your soils, snow loads, and winds.
If it is very high, say over 1 foot, the downward load on the hangar due to its weight and any other loads such as wind or snow will generate a "kick-out" load on the stem wall. To simplify, consider the hangar finished and sitting on a smooth slick surface. If you push down on the apex of the building, the bottom edges of the building will try to move outward under the load. The stem wall is there to react that kick-out load.
If the stem wall is high, the junction between the hangar and the stem wall will act as a hinge and the top of the stem wall will want to rotate outward from the hangar. So the stem wall must be designed to react that load and not move.
If the stem wall is low, it must also be designed so that the kick-out load will not push the entire wall outward under load.
Commonly, the kick-out loads are reacted by tension beams under the floor tied into the stem wall so any kick-out loads just cause tension in the beams and do not allow the stem wall to move.
It is my opinion it would be money well spent to hire an engineer to design your stem wall specifically for your location taking into consideration your soils, snow loads, and winds.
Richard Pulley
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
Re: Quonset Hut hanger
And the tension loads on those sub-foundation beams...is why rebar is a good idea in them.hilltop170 wrote:....Commonly, the kick-out loads are reacted by tension beams under the floor tied into the stem wall so any kick-out loads just cause tension in the beams and do not allow the stem wall to move.....
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
Re: Quonset Hut hanger
Richard has it about right along with GAHorn about rebar and the stem walls, but what is not mentioned at all is WIND if the doors are open. The uplift forces far and away excede any live load on the building diafram. This produces a compression load on the slab or tention beam and destroys more quanset buildings than any live load ever has.
If you take a 40 foot pipe and bury it half way you have a very stout quanset 20 feet high and 40 feet wide. Cut the pipe in half and replace the bottom half with a concrete footing and stem wall you have the standard quancet building which must be tied together very well to replace the structural integrety of the full pipe.
I can go on and on but suffice it to say you must complete the circle somehow to achive structural integurity.
Scott.....use to be 53B, now flying a 50A.
If you take a 40 foot pipe and bury it half way you have a very stout quanset 20 feet high and 40 feet wide. Cut the pipe in half and replace the bottom half with a concrete footing and stem wall you have the standard quancet building which must be tied together very well to replace the structural integrety of the full pipe.
I can go on and on but suffice it to say you must complete the circle somehow to achive structural integurity.
Scott.....use to be 53B, now flying a 50A.
Re: Quonset Hut hanger
Thanks for all the input-- I will go back over each one to understand the importance imbedded in each message.I met with the contractor last night and we have agreed-- lots of rebar, proper cement mix , and continue wall around the corners on all sides with rebar tied in across open space for extra rigidity.
The big concern up here is the snow accumulation, but there is room ( about 8-9 ft.) between my building and others to allow for any snow removal required.We do get a big blow sometimes, but with hills all around the field we are spared the damaging stuff some of you in the central states area receive all too often.
Don't you hate to make a statement like that--I'll just get it finished and we will have the biggest storm ever to pass through our area!
Pictures to follow!!
The big concern up here is the snow accumulation, but there is room ( about 8-9 ft.) between my building and others to allow for any snow removal required.We do get a big blow sometimes, but with hills all around the field we are spared the damaging stuff some of you in the central states area receive all too often.
Don't you hate to make a statement like that--I'll just get it finished and we will have the biggest storm ever to pass through our area!
Pictures to follow!!
Re: Quonset Hut hanger
Well, fineally starting the construction!
At least the prep work is under way.
Several loads of good packing base now compacted, and footings frames being constructed,lots of re-bar bending, and maybe start to pour Tuesday or Wed.
I tried to attach some pics of the site and my white and RED 170B but couldn't get them on.
I will keep at it.
I remember seeing a post about posting pics so I'll get to that shortly so as to show progress.
At least the prep work is under way.
Several loads of good packing base now compacted, and footings frames being constructed,lots of re-bar bending, and maybe start to pour Tuesday or Wed.
I tried to attach some pics of the site and my white and RED 170B but couldn't get them on.
I will keep at it.
I remember seeing a post about posting pics so I'll get to that shortly so as to show progress.
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W.J.Langholz
- Posts: 1068
- Joined: Sat Jul 26, 2008 1:56 pm
Re: Quonset Hut hanger
A well placed buttress or 2 may be in order as well....gahorn wrote:And the tension loads on those sub-foundation beams...is why rebar is a good idea in them.hilltop170 wrote:....Commonly, the kick-out loads are reacted by tension beams under the floor tied into the stem wall so any kick-out loads just cause tension in the beams and do not allow the stem wall to move.....
W.
May there always be and Angel flying with you.Loyalty above all else except honor.
1942 Stearman 450
1946 Super Champ 7AC
Re: Quonset Hut hanger
The framing for walls is coming along-- perhaps pour today.
We have planned to continue side walls across front and back ( turn corner and continue for 4 feet each side) for further strength and rebar connecting each wall. As well, a centre rebar connecting each side wall together at mid point and this will be covered by a floor of hard packed screenings.
All cement quality, rebar diameters are equivalent or greater than engineered drawings- -overbuild ?
Question, I will go back and look over emails , but I don't recall any mention of gasket --weatherproofing between each section.
The plans suggest it, I just don't see how the rain can get in with the shape as each section is constructed under the higher piece so water will run down from one to the next.
Am I missing something?
Thanks,
Pat
We have planned to continue side walls across front and back ( turn corner and continue for 4 feet each side) for further strength and rebar connecting each wall. As well, a centre rebar connecting each side wall together at mid point and this will be covered by a floor of hard packed screenings.
All cement quality, rebar diameters are equivalent or greater than engineered drawings- -overbuild ?
Question, I will go back and look over emails , but I don't recall any mention of gasket --weatherproofing between each section.
The plans suggest it, I just don't see how the rain can get in with the shape as each section is constructed under the higher piece so water will run down from one to the next.
Am I missing something?
Thanks,
Pat