Terra-Dome Earth Shelter Build

[newbury]

I've long dreamed of building, and owning an earth home. Congratulations! My property is in a 100 year flood plain, and even though the FEMA maps are very inaccurate, the county would never allow me to put an earth home here. My next choice to replace my 1973 mobil home is a geodesic dome. Whatever I do, they will make me pay through the nose with permits, and flood plain certificates. Having been here 33 years, I am the expert on my property - not them.

Remember the "100 yr flood plain" is based on past climate and geography. With the ever increasing clearing and parking lots the old 100 yr flood plain may now be the 5 yr flood plain with upstream changes.

 

[SamWalton]

How are you addressing Radon? Tight construction and underground construction with lots of concrete can make for unhealthy Radon levels unless addressed.

How much structural capacity did the engineer give your roof? Usually there is at least 18" of soil over the roof so the grass does not dry out - otherwise the roof needs to be watered.

What is the contractor using for waterproofing? Did the concrete spec include fly ash to make the concrete less porus - more dense and watertight?

Did the engineer design the concrete to meet ACI-318 code requirements?

Good Luck,

Yooper Dave

There is not much radon in Sallisaw Ok but we will have 3/4 chip stone and French drains inside and outside the footings and under the slab along with a heavy plastic vapor barrier. Our earth shelter home design is above grade with the earth bermed over from east to west. We have two fresh air intakes under the wood stove locations. The superimposed design load of the Terra-Dome is 327 lb. per square foot has included an auto live load of 50 lb. per square foot. Basically it can handle 80,000 lbs of load on the roof. The concrete has fly ash from the local power plants but doesn't pose any health risk. We will be using Econline-R and Econline-T as our waterproofing membrane, which is a tar modified polyurethane elastomer. It is applied to a thickness of 1/16 inch. A bentonite sheet material is also used in conjunction with rubber membrane on parapet walls and cold joints. I don't know about your ACI-318 spec but the web site tells you about many of the specs and they provide a design which provides massive overkill.

 

[SamWalton]

Today we were moving some earth for the south retaining wall but got rained out. Terra-Dome workers are just a few hours from completing the first module for our 6:00am pour on Monday.

 

[tommu56]

Sam do they pour it in one shot from foundation to top of roof?

tom

 

[SamWalton]

Sam do they pour it in one shot from foundation to top of roof?

tom

Yes module is poured at one time (monolithic pour).

The storm passed and we all went back to work. It looks like they will finish all the preparation work before the pour tomorrow.

 

[SamWalton]

Those forms are very impressive!!! I didn't realize there would be so much height to the rooms.

What sized rebar are you using? Do you have to use a special mix of concrete? Do you have a permit? I'd be curious about the process of getting the permit and the inspection process, but then again, I woudn't want to be the one to do it, just like to hear about it if you have to have one.

Thanks for the updates,
Eddie

We use all 5/8" in the footings but the uprights are 1/2" The walls are all 10" thick concrete and 8' tall with #4 rebar at 12' X 12" centers each way. The domes are 1/2" and a bit smaller but have 2100 lbs of rebar on the roof alone.
The rooting use 3500PSI and the domes use 4000PSI concrete. We require no permit other than DEQ for septic.

 

[jinman]

Sam, I know you are busy today with your pour, so when you get time, I'm curious about the curved rebar on your roof. In the photo below, is the rebar finished, or did they add the curved component all the way to the top of the roof? That just really caught my eye as being unusual.

 

[SamWalton]

Sam, I know you are busy today with your pour, so when you get time, I'm curious about the curved rebar on your roof. In the photo below, is the rebar finished, or did they add the curved component all the way to the top of the roof? That just really caught my eye as being unusual.

The different layers of rebar are to add strengh and what you see is complete except for the electrical conduit and boxes on the roof area which will be completed today.

 

[woodlandfarms]

Sam, what if any of the forms stay with the house? does the roof form come out, or the wall forms, or are the wall forms insulation and just stay?

 

[SamWalton]

Sam, what if any of the forms stay with the house? does the roof form come out, or the wall forms, or are the wall forms insulation and just stay?

All of the forms are sprayed with a special oil to allow for easy disassembly and are used over and over. We have three more domes and one flat roof section. This crew is working very have to provide a quality product. It is really a whole lot of very hard work to build these types of structures. It is very much like building a bridge.

Tomorrow we will finish the footings and also install the 2 1/2" service entrance conduits, which goes to our transfer switch first then off too our 200 amp breaker panel. We will also install other size schedule 40 plastic conduit for the fresh air intake for the wood boiler and a few extra for thins we may think of later.

 

[patrick_g]

...about all the underground or earth sheltered type comments... didn't anyone notice the "on grade" foundations or the slab on grade floor. If this project is to be earth sheltered it will be buried in dirt after the exterior and any other load bearing walls have cured sufficiently.

There is a wide variety of degrees of earth cover in common use ranging from little or no berming to virtually complete coverage.

If anyone is interested in acquiring a fair library of books about earth sheltered construction, PM me as I have a fair selection left which are surplus to my needs since I went with a walkout basement with part of the ground floor in ICF's.

MY house project is chronicled at the sister site in the Home Building section.

CountryByNet.com Forums :: South Central Oklahoma Farmhouse

It is 22 pages with 159183 views to date.

Pat

 

[SamWalton]

...about all the underground or earth sheltered type comments... didn't anyone notice the "on grade" foundations or the slab on grade floor. If this project is to be earth sheltered it will be buried in dirt after the exterior and any other load bearing walls have cured sufficiently.

There is a wide variety of degrees of earth cover in common use ranging from little or no berming to virtually complete coverage.

If anyone is interested in acquiring a fair library of books about earth sheltered construction, PM me as I have a fair selection left which are surplus to my needs since I went with a walkout basement with part of the ground floor in ICF's.

MY house project is chronicled at the sister site in the Home Building section.

CountryByNet.com Forums :: South Central Oklahoma Farmhouse

It is 22 pages with 159183 views to date.

Pat

Thanks Pat,
It is nice to hear from a seasoned mole. I began my underground experience in the U.S. Army at the Adams county Pennsylvania Raven Rock Mountain Complex better known as Site R. This facility had two power plants and an underground lake and many other things I can't mention. As for our Terra-Dome, we will be earth covering the structure from east to west after the water proofing and drainage systems are installed. I also have a fine collection of earth sheltering books, one of which is a PDF file. "Earth sheltered homes plans and designs.pdf" the file is 26MB. It you could receive a large email I will send to all how are interested.

 

[MarkV]

Wow Sam the project is looking great. The way they form the roof is really something. It looks like it will take a good amount of dirt to cover that much structure. Will you be bringing it in or using soil from your property?

MarkV

 

[SamWalton]

Wow Sam the project is looking great. The way they form the roof is really something. It looks like it will take a good amount of dirt to cover that much structure. Will you be bringing it in or using soil from your property?

MarkV

We hope to use what we have at the home site but have about 30 acres to work with.

 

[hogi]

Sam, Thanks for taking the time to document for us this fascinating project. I know this may be a taboo subject but how much do you expect this whole project will cost minus governmental fees and the initial cost of the land. And if that isn't too personal already, how much is just the building envelope, i.e. structure, w/ doors, windows but minus interior finish?

 

[patrick_g]

Sam, I was pleased to read you are installing in-slab heat. Just a couple comments regarding personal luxury etc. Our master bath shower has no door nor curtains and does not splash water out into the rest of the bathroom. Very little cleaning required (yeah, maybe I am lazy.) There is closer spaced PEX in the shower floor AND in the tile walls of the shower. If I had it to do over I would override my HVAC contractors input and continue the PEX in the shower walls all the way to the ceiling (not just 5 ft) and I'd do the ceiling too. My shower is pretty luxurious but the changes noted would have make it superb.

The towel rack next to the shower is hollow tubing and the hot water flows through it on the way to the shower walls. Towels are warm and dry (I don't always use a fresh towel every time I shower.)

If you haven't got an ERV or HRV in your HVAC plan please consider it. A really tight house needs something like that. Mine runs 24-7 on well under an amp and keeps us economically supplied with fresh air. The integral heat exchanger really saves on conditioned air (heated or cooled) and keeps ventilation costs very low.

Pat

 

[SamWalton]

The forms are coming off and it is nice to finally see from plans to reality. The large opening on the north facing side is going to be a window identical to the ones on either side of it.

The footings are missing there because this is where the sewer line will leave and also the fresh air intake for the wood stove in the great room module. We will have a second fresh air intake for our Greenwood wood boiler Model 100.

This greenwood is a great deal for anyone who is looking for the best design in Hydronic Wood Furnaces and since the company is closing the prices will never be better.

Greenwood Furnace Series Indoor Wood Boiler and Wood Furnace

 

[SamWalton]

We pour the second dome.

 

[hobie]

Wow! Great to see your updates! Please keep em coming.

 

[SamWalton]

It was way cool watching them and listening to them lower the mother ship of all domes. The hydraulics made a resonating sound during the lower.

I drove our Kubota into our bedroom to lift and drag the dome form trailer to get it in position to pull out the small opening.

After aligning the dome trailer they towed it away.

My son Travis spreads the 3/4" chip in the remaining areas of our home to be. What fun!