I almost gave up on my dream of building a house on my mountain property because I am in my 60’s, don’t have enough cash to quickly build a house, and don’t want a loan. Well, I recently bought a large metal arch building kit (45Wx74Lx17H) for a good price on Craig’s List. Now my plan is to use about half of it for a habitat. The rest will be garage and shed roofs using smaller sections of the arches. The initial erection of the metal arches does require engineering approval and a permit, but not as extensive as the permits for a habitat. Permits have time limits, so planning, labor and material costs are usually simultaneous if the permit process begins for a habitat. If it is not completed in a year, permit extensions must be bought. If it begins as an apparent “garage”, subsequent steps to make it into a habitat can be timed as the opportunity arises. Electricity could be added after the arches are erected. Adding a bathroom to the inside of the “garage” would require a plumbing permit, as well as a permit for the room. While the cost for material and labor are still real, the expenditures can be gradual and the chances for good bargains are better. So it begins as just a metal arch building. Now is my time for planning how to convert the thing into a habitat. I am seeking your thoughts and ideas regarding making a quanset hut into a house. The arch will go from E to W. Entry will be on the E side of the arch. The S flat building surface would have a lot of windows. The N flat building surface would be 6ft below grade. The habitat space beneath the arch will be 35ftx~30-40ft if the base of the arch is at ground level. The site has electric, well, and septic left from the burned down house prior to my purchase. The first question I have would be whether a spray foam insulation on the inside surface would be be the best choice. There will be more questions as I read your replies. Thanks. Gary

Gary - you don't mention where you are located so we don't know how much insulation you need. But yes foam is usually a good match for steel. If you need a fair bit of insulation it might get expensive.
You might consider framing up some walls inside the quonset and just insulating them with Roxul or some other insulation that is much cheaper than foam. If your building is 45' wide you might consider leaving 8 to 10 foot runways on each side to use as storage or like a breezeway. See where you wind up with 8' of clear height and locate the walls there if that worked. At 17' high you might even work in a second floor. That way you would not have all that height to heat.

If you look over in the sips forum, you will read about someone thinking of reusing freezer panels for a house skins. The resident experts didn't agree with him but in your case it would be all inside and you are only looking for insulation value, not weather proofing. These panels sometimes become available quite cheap. Look around.
Just some thoughts.

Thanks for the reply FBBP.

My property is in south central CO, just south of the Arkansas River and east of the Sangre de Cristo mtns at the end of the Wet Mountains.

I don't recall what the code requirements for insulation are. I was thinking that the spray foam layer would satisfy the county for a "garage". But it certainly would not be enough for a habitat. I am inclined to have a lot more insulation than minimum code.

Since the metal will get hot in the summer and cold in the winter, I am thinking I would use papercrete to cover the outside. I have the mixer and a pneumatic sprayer, but it may take years to completely cover the outside surface.

I have read many of the threads in this group about SIPS. They are of great interest to me for the habitat inside the quanset. I am thinking MgO SIPs (first read about them here). I think they are adequately vapor resistant and if sealed correctly can be the radon barrier portion of the reduction system. Since my property is on a granite mountain, radon is of concern. So a radon reduction system is important to me, even if my county doesn't insist.

My septic system is sized for 2 bedrooms ~1000 sq ft.

If I measure the width of the quanset that is 8ft high it is ~35ft wide. If I add a foot for a ceiling/floor, the second floor would be ~13ft wide if the insulation on the quanset is ~4". I would need window(s) of egress.

Since the quanset is a structurally sound shell, the living spaces (SIP boxes) beneath the shell do not have to be in direct contact with the shell. The living spaces also do not have to be in direct contact with each other and share walls, but cost would be lower if some walls are shared.

If the SIP boxes are inside a foam lined quanset, how thick should the foam be on the quanset and the SIPs? Does the space between the quanset and the living spaces add to the R value?

I am thinking a small HRV for each SIP box. Can those HRV's interface with the air in the space between the quanset and the SIP boxes? Or do they need to be vented outside for each HRV?"

Thanks again.

http://en.wikipedia.org/wiki/Quonset_hut

I lived next to Quonset Navel base growing up.

ChrisJ

Hi Gary,
I'm retired & I have built a steel quonset 40' x 50' just S. of Florissant about an hour or so up Hwy 9 N. of you.
I'm pondering the same questions as you. It is built into a E. facing hill.
I had the septic system engineered and tied into the slab when built.
Teller county has strict code enforcement & is still at IRC 2003 code, zone 5, which requires R39 roof & R19 walls.
Quonset is far outside the norm. Hard to say how to meet code.
Good Luck BBP

The shape is intrinsically thermally efficient and will not present typical loads. I like foam. I would talk to the code official with a proper heat load in hand. It would be lower than a building presenting the same footprint but with half the insulation as I recall. If the building starts as a garage and ends up a house, you would not be the first to run out of money. I have many clients living in garages. And some of them are still married!

Thanks for the replies, guys.

BuffaloBillPatrick, I look at the sign for hwy9 as I head down to the Arkansas River on my way to the property. Interesting that you have erected a Quonset. The engineer I spoke with said the foundation is a bit difficult, but important. Fremont County is still on 2003, but they probably have not adapted all the code. Radon for example does not appear to even be a concern to the county.

I found another insulation product, K-13. http://www.retrotherm.com/k13.html. It is cellulose that can be sprayed onto about any surface as thick as 5" without any support. I like this from what I have read. It will solve my major concern about condensation.

The problems I see with a foam spray are 1) I would have to pay someone with good enough equipment to spray it all at once, or rent scaffolding and spray it myself; and 2) the finished foam surface is not adequate for the inside of rooms, hence, it must be covered if some of the inside of the Quonset arch is open to some of the living spaces.

Interesting thought to consider Badgeroiler

(continued from above) to BadgerBoilerMN

Running out of money is easy when there is no loan, other of life's expenses drain the pocket and all things are paid for up front. At least I don't have to live in the thing if there isn't enough money to finish the job quickly. It is basically just a vacation home. Running out of money does cause unwelcome delays.

My goal is to have fun doing it. Thanks again for the input.
Gary

Posted By Gary Olsen on 22 Mar 2013 08:56 AM
Thanks for the reply FBBP.

My property is in south central CO, just south of the Arkansas River and east of the Sangre de Cristo mtns at the end of the Wet Mountains.

I helped friend with his home-building project near this area.  He's up Copper Gulch Road about 15 miles Southwest of the Royal Gorge.  I'm thinking that you're in Fremont county.  The inspectors are pretty tough there.  Another friend in the same county (North of Highway 50), has renewed his permit 6 times.  He's doing everything himself, and now his health is failing.  Going on #7 soon.

Was the Gorge fire near your property?

Thanks for the reply Jim,

My road comes off Copper Gulch Road 15 miles north of Parkdale. It is Fremont County. The inspectors are pretty tough. Some engineers do not want to do business in Fremont County.

I hope your friends are doing OK with the wild fires in the area. The gorge fire did not damage many homes, just commercial buildings and the bridge. The bridge may not open this year. I drove through Temple Canyon (straight south of the gorge) Tuesday. The fire was mostly in the steep canyon land. There was another fire straight north of Texas Creek. It was small and contained.

Although I did not choose a Quonset hut due to the fires, it seems like a lucky choice. One engineer I spoke with said metal buildings do not necessarily prevent fire from torching the inside of the building. Drapes and furniture near a window will catch fire even though the outside of the structure does not.

Normally, I can see the Sangre de Cristo mountains, by just looking out the windows of my earth home on the Front Range prarie. It's a beautiful view. Nowadays, however, all I see is a haze. Those fires in Southern Colorado are really burning up some acreage.

Earth home on the Front Range prairie!! Awesome.
It is sad to see smoke in the southern skies.

Posted By Gary Olsen on 29 Jun 2013 08:58 AM
Earth home on the Front Range prairie!! Awesome.
It is sad to see smoke in the southern skies.

Yeah, I posted a thread with some pictures, in the Residential section.  Check it out...

We've gotten some good rainstorms the last 2 days.  Have you seen any of it?  Evidently Durango, and the Southwest hasn't, as they're still reporting high danger.  I just read that the West Fork fire has grown to 80,000 acres.  To put this in perspective, an acre is slightly smaller than an American football field.  No wonder firefighters have trouble fighting these things.

In another group someone mentioned his experience in a Quonset hut in Iraq. He said the Quonset was covered with "sand". He said it was a lot cooler inside as well as being bomb proof.

Hmmm!
Could I cover my Quonset with backfill from my property? How thick?
I am guessing that I would need to build a retaining wall and the height would be influenced by the backfill depth.
Would a layer of backfill eliminate some of the condensation?
Wouldn't backfill on top of the Quonset count as insulation too?

Thanks for replies.

I realize I would need to get an engineer to sign off on the design. Is it worth pursuing?

I wouldn't think so. You'll have a very difficult time, keeping the roof from leaking. Nothing ruins a home worse than intrusive water. I agree with others who said that spray foam insulation would be the best option. Framing (with batt) would be more expensive, and a lot more work. I know somebody in that area who is retired, but has all the equipment to do spray foam. You might get a better price from him. A friend of mine used him for his bermed earth home. They both live out Copper Gulch, a little past Poverty Mountain.