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Underground housing  RSS feed

 
Posts: 95
Location: Central TN
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What if I just buy home depot lumber and build? What kind of overbuilding would I need from typical framework in order to support the additional load of earth?
 
pollinator
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I do not know to be honest with you because I thought of this myself. I have built above ground structures for my barn that was REALLY cheap (see the link regarding my 30 X 48 Barn for $4450). I can walk on that with ease and no deflection, so maybe by beefing it up a bit I could build a stick-built WOFATI. Now honestly that sounds like an oxy-moron (a stick built WOFATI), but the genius of the thing is its versatility.

I don't have time to look up the load bearing characteristics of wood, but I did the 8 x 8 beams in my house and since the beams are sharing load points (and not a single load point) it could hold over 4500 pounds. In practical terms, that is the ability of (2) 8 x 8 beams spanning a 12 foot stream and still hold up my bulldozer without breaking. That is a lot more stress than dirt spread evenly over a broad surface!

I do not think it would be that hard though. Built up framing lumber into beams has more strength then squared timbers so you could easily make carrying beams over windows and doors, then for the rafters, just go with 2 x 12's instead of 2 x 6's, or use more carrying beams so the spans were half as long. For posts...if you are not against presure treated wood, is to insert that into the 4 foot hole, then stagger the joints a foot or so out of the hole and then scab on regular framing lumber to form (3) 2 x 6's to make a built-up 6 x 6 post. I am probably not being very clear, but you would end up with the bottom 4-5 feet being pressure treated. I have seen a lot of buildings built like that and are still standing. Of course if you are opposed to pressure treated wood, you could just char it, or have rot-resitant wood like hatchback or cedar sawn out for you.

One thing I plan to do is use a membrane for my umbrella like everyone does (and rightfully so), but for the ceiling I plan to install steel roofing. This has some advantages. It adds lateral stability to the structure thanks to the seams that "lock" it together and keep the building from wracking. It would also be a second level of protection from water infiltration if the umbrella leaked. But it would also help support the soil. Steel is very strong which is why I can walk on such thin sheets on 4 foot rafter spacing's with 2 foot spacing's of purlings. I will have to look up at it as I live in my WOFATI, but we have the look in my barn and I kind of like it. And it should not rust or rot as the soil above should always be dry.
 
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If you read extensively in Oehler, he mentions that he has a lot of troubles with gophers. You may or may not, depending where you are. But critters live in the ground, and this must be taken into consideration. Maybe a lining of hardware cloth or some other kind of wire mesh between the soil and the plastic would be helpful.

Also, plastic breaks down over time. Not so that it goes away but so that its structural integrity is compromised and it breaks into microparticles. So you might design so that in ten, fifteen years, it would be accessible to go in and replace the plastic.
 
Posts: 137
Location: Maritimes , Eastern Canada
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Alot of issues , including cost, can be solved by building the structure in concrete block.

Its easy to learn (lego for adults) solid, Inorganic ( which helps eliminate mould ) ,critter can't get through, Fireproof ( a huge plus) and easily exolated with either foam sheets or mineral wool.

It is also easy to make a curving or circular house using blocks.

Insulating under and around the whole structure a must.

Electric heat cable can be laid in the floor slab or at least in the bathroom

On the interior finish a parge or stucco in any style or colour you like . Or raw block can be strapped and covered with panelling or surface of choice.

Important tip on insulation. Do not use foam on the inside, only outside and preferably only under ground or against ground.

If interior insulation is needed use compact mineral wool , Roxul comfortboard IS very nice and takes stucco very well as it is made from stone.

As a mason , I am always wondering why more people don't do these builds in block which is also very economical .

The groundwork is all important. COmpact 3/4 - gravel, preferably of limestone, as a base. Don't lay out more than 6 inches per layer. Keep it as level and smooth as possible.

Lay out the foam ( min. 1.5 in) two feet past where the edge of your slab will be.

Lay out steel mesh(6 in x 4x8 ft) with re bar around perimeter.

Pour minimum 5 inch slab .

You should have the slab engineered if there is to be heavy load or other special conditions.

Build your block walls on this. Let slab extend minimum 1 foot past wall and foam under slab past this.

Common or recycled brick will make nice partitions, 4 inch block also good for these.

Again, As a mason  I believe in this simple building method but mainstream building is all wooden framing with all its layers and cavities - rodent heaven!!

The exterior of the structure is easily waterproofed with a paintable membrane and then a blueskin or other heavy membrane. THe heavy industrial ones that are welded on by specialists are the highest quality and probably advisable under or against the ground.



 
Mark Deichmann
Posts: 137
Location: Maritimes , Eastern Canada
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I just wanted to add a tip about insulation. The foam should always be EXTRUDED RIGID type, do not use the white styrofoam , even if it costs alot less. It will break easily and the little balls of foam it is made of are perfect for ants to pick out. They will hollow it out.

We have Seen older white styro sheets completely gutted by ants. Only the outer shell/stucco remaining. The rigid foam is inpenetrable.

Just wanted to pass these tips along. I still see people building without insulated the foundation at all or using the white foam.

ALso that a "cob" look can easily be obtained using block and mortar and a brush.

Most trade schools/community colleges offer basic bricklaying/block courses. But its easy to learn the basics , maybe hire a local mason to get started a few days.

 
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posting here and on 48hrs as requested. Thank you for your time. Also, I realized that I wrote "I have to know before I forget". How rude can I be. ugh!!
> I'm reading as fast as I can, but I have to know before I forget. Regarding a post from 2009 Underground Housing, did you build the structure pictured for $1k?
>
> Post by: paul wheaton , master steward
> Jun 10, 2009 07:29:23
> +1 -1 Quote Report
> So I'm combining a lot of ideas from a lot of people and coming to a new space amd I just need to express it.
>
> First, we have
>
> Sepp, building a shelter in a day (above).
>

> Total cost for the structure is about $1000 (two layers of felt and one layer of pond liner) plus the cost of the track-hoe.  Note that the soil is a meter deep over the structure.
>
> And then we have Mike Oehler's designs that are in many ways similar - with light coming in all four directions.
>
> Then add in the idea of the umbrella architecture:

below this was a picture of the dwelling
 
gardener
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Shelah Horvitz wrote:If you read extensively in Oehler, he mentions that he has a lot of troubles with gophers. You may or may not, depending where you are. But critters live in the ground, and this must be taken into consideration. Maybe a lining of hardware cloth or some other kind of wire mesh between the soil and the plastic would be helpful.

Also, plastic breaks down over time. Not so that it goes away but so that its structural integrity is compromised and it breaks into microparticles. So you might design so that in ten, fifteen years, it would be accessible to go in and replace the plastic.



Just to clarify on this point, the poly plastic breaks down under UV exposure. Since it's buried in soil it doesn't receive that exposure and won't break down. The main issue is punctures during installation or not screening the soil you add as described in Mike's book and then that rough rocky soil presses against the material and causes a leak. As described in the book, if you have 2 layers of plastic with several inches of soil between it can help minimize the risk of water getting through both.

For critters, I think Mike mentioned that one time he had an invader, who made a straight shot to his root cellar or pantry where he had some food not properly sealed up. After cleaning that up he didn't have further issues (from what I recall), but had regular issues with them in his greenhouse.
 
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Seen a sort of cave/cellar made in sandstone. The place never gets wet/humid, no matter how much is rains, (and it does rain a lot around here). All the other cellars I've seen around here are always damp and often have mold. This sandstone place is super simple, just a hole in the hill with a door, but could easily become a pleasant little home. Unfortunately students go there and get drunk and there are broken glass bottles everywhere. I get real angry when I see this. Something similar I was in one of the canary Island La Palma, there where caves where people used to live in, but because there were so much more people around in the area, they were somehow converted to toilets, you could see toilet paper everywhere in them, disgusting. These caves could have been great places to live in.
 
Posts: 8
Location: northern california
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My one take on underground buildings is simple:  it'll eventually leak.  There are SO many variables.  Even the PAHS homes have issues - and they are only partially underground.  i spent an engineering career in commercial and industrial building operations... and even with their $$$$ budgets and toxic waterproofing materials used - eventually even they leak:  cracked floors, shifting & leaking roofs, etc.   The big issue is TIME:  you might be alright for the first 5 years - but eventually the ground shifts, shit happens, and triple+ waterproofing cracks.  Water intrusion and even worse: freezing water/moisture eventually erodes the building's substructure.
My advice:  find a nice cave, and let nature do the work, or maybe re-incarnate as a ground hog :-)
 
pollinator
Posts: 780
Location: Pac Northwest, east of the Cascades
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Fred Klammt wrote:My one take on underground buildings is simple:  it'll eventually leak.  There are SO many variables.  Even the PAHS homes have issues - and they are only partially underground.  i spent an engineering career in commercial and industrial building operations... and even with their $$$$ budgets and toxic waterproofing materials used - eventually even they leak:  cracked floors, shifting & leaking roofs, etc.   The big issue is TIME:  you might be alright for the first 5 years - but eventually the ground shifts, shit happens, and triple+ waterproofing cracks.  Water intrusion and even worse: freezing water/moisture eventually erodes the building's substructure.
My advice:  find a nice cave, and let nature do the work, or maybe re-incarnate as a ground hog :-)



That could be said of any building though. Eventually the roof will fail, animals will get in the walls, the plumbing will go, etc... Time wins against all of humanity's creation, even nuclear waste will eventually return harmlessly to the earth if your patient enough.

A lot of the issues with underground homes is extremely poor planning, really just not thinking it through. Thinking over application of water proofing will solve the problem of water. Or forgetting about frost heave, or animals.

You can plan ahead and build underground and earth sheltered well. You can do things like Oehler and others have figured out to head off many of the worst mistakes commonly made by those trying to build underground. You can be prepared to excavate and fix replace things if something does go wrong.

Or you could do things like Baldassare Forestiere http://www.undergroundgardens.com/about



Or you could do it like Ra Paulette https://www.atlasobscura.com/places/ra-paulette-s-hand-carved-caves



And build highly different types of cave homes using unique properties of uncommon types of earth and then use methods similar to any burrowing animal does to control heat and cold and water.

My point is, it is easy to say something will happen, but you can plan the best you can and be prepared to fix what has to get fixed. As well as remember most stick homes these days start to fall apart 5-10 yrs. They sure don't make 'em like they used to.

This is why the home I am designing to be an earth sheltered home is basically a timber frame home. Timber frame lasts 100's of years if done right. It is extremely good at baring heavy loads. In an earth sheltered situation, it could handle being unearthed and reburied.
 
Mark Brunnr
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Mike Oehler spent 30 years in his underground house (which the wofati is based on), and passed on what he learned compared to building the "first thought house" that most underground houses are based on, with water penetration the #1 issue. While it's inevitable that a leak will develop over the years/decades, that's true of any home. A big tree branch can fall and puncture the umbrella sitting a foot under the soil surface, and can also fall through the shingle/sheeting roof of a typical frame house. A french drain sitting at the edge of the umbrella could be poorly installed and fail to drain or clogs up and lets water back up under the insulated mass or even worse reach the buried posts. Or the building is placed in a flood plain or in a location that a french drain can't handle.

But all of those issues are either out of your control or due to poor planning/design, and not so much due to structure itself.
 
master steward
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I just want to state that this thread now has 702,726 views.

I remember when this forum was super tiny - I was just starting it.  And I saw in another forum a fella tried to ask about this stuff and he was shouted down in a particularly ugly way.   So I wrote to this person and invited him to post here - and told him he would not be shouted down.

This is thread number 959.  So when this thread started, there were not yet 1000 threads on this site.  And now there are over 100,000.  

I just had a warm, fuzzy feeling to share when I saw this thread being bumped.

 
Devin Lavign
pollinator
Posts: 780
Location: Pac Northwest, east of the Cascades
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That is awesome Paul. Thanks for putting this thread into perspective.
 
Fred Klammt
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Location: northern california
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If I had an excavator** or a bunch of strong young backs, I'd site a PAHS 'umbrella' house on southwest sloping land - for max winter solar gain.  I'd only put 1/2 half (the north side) of the house underground.  I'd put in a deeply anchored rubble or cinderblock wall (maybe two walls with a french drain in between) on the north side and/or a combo of Sepp Holzer's root cellar designs to prevent future 'mudslides'.  the airflows and thermal mass storage of the PAHS are ingenious... ( The initial PAHS concept came from   Dr. Hiatt of RMI in the 1970's) .   The underground roof part would be tricky... eventually it'll leak (just ask the GAP facility manager who maintained the first green roof in South San Fran in the 1980's) - plant roots are amazing and water will follow!    ....when the 'bird of paradise' deposits  some willow or elm tree seeds on the roof...

**  Excavation is the cheapest form of construction.
 
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