Joshua Plymouth

So glad that there is a thread about this concept already.

Over the past year I have been looking into building an earth berm(underground) house. However, the events this year have proven to make things difficult. Between the virus struggle and the political turmoil it was hard to catch a break, and much harder to scrounge up materials. Seeing as housing materials, especially wood costs have become much more expensive. The reason behind this is not clear, whether it is simply shrewd business men taking advantage of the hurricanes, or if it is a more politically motivated action it has not made things any easier. Strange times indeed…

After scrounging up all of the materials I can over the past 6 months through auctions, salvaging, and searching I now see that even if I go with the earth-carpet floor, it will be no small feat to get enough wood for the walls and roof of the structure.

Reading through this thread seeing people mention concrete really worries me because concrete is not cheap, nor is it fun to work with. Mike Oehler hated the stuff.

If someone wanted to follow the Wofati-Oehler design how could they do it with a mobile home? The trailer structure is not load-bearing at all. Someone mentioned in this thread laying a small car on top of one would cause it to collapse, so putting support beams is a must. Also a shed roof is a must. seeing as the current roof is somewhat flat. Putting the beams straight through the walls of the trailer would not be easy… beams would have to be outside of the trailer. Would it be possible to lay poly against the back of the trailer and backfill or would that cause the pressure to break the walls? Would there still need to be some sort of shoring between the posts? perhaps that is simply a question of whether or not the walls of a trailer can withstand any weight behind them. The trailer is 50 feet by 12. Please offer any suggestions or info you can, Although if you are going to tell me trailers suck, trust me I know. But you know whats worse than trailers right now? Wood prices, and if things keep going this way getting my hands on all the necessary materials to build an underground house right is not going to be possible.

What it reminds me of is the wofati shed that they built, simply a cheap underground structure devoid of moisture… however I do not have nearly that many logs, so how would I get around that fact?
https://www.youtube.com/watch?v=OkIglvErt3w&ab_channel=Dirtpatcheaven

R Scott wrote:Poly tape.  The red stuff.  Used in conventional building for vapor barrier under concrete. Patch holes, seam sheets together, wrap posts, transition between floor and walls, etc.

This is the only thing I could see working. Sealing the plastic to the poly sheets that it penetrates to sink 2 feet into the earth. Taping it, painting it, and sealing it in any way possible, however this would require that you wrap the posts in something much more sturdy than trash bags, seeing as that would not seal well to 6 mil sheets. Does anyone have experience with this idea? Or descriptions of the process? even pictures?

Trace Oswald wrote:Mike wrapped his posts in several layers of trash bags and then put the floor poly around the posts.

Here is a drawing of what I am seeing in my mind. The last one is the one with the trashbag. Even though that keeps the post dry, that does not prevent water from rising through the holes in the poly sheet where the post goes through. I live in a wet area, where the water table sometimes rises. Even if one were to use metal coats for the posts that does not stop the puncture in the sheet.

Mike Oehler Himself wrote:The polyethylene is a moisture barrier, an absolute one, but it can remain so only if it is not pierced, torn or punctured.

One area that others and I have struggled with when looking at earthberm, Wofati, Mike Oehler and any pole/polyethylene floor structures is understanding how to wrap the floor polyethylene such that it keeps moisture out, but allows the wooden posts to sink 2 feet below the surface. Especially when dealing with an earth-carpet floor. For many of the Wofati structures the floor is wood, but how did Oehler do it when he made it directly on the earth? How did he keep water from coming up the posts, especially if you were in a wetter area than where he lived? Reading through His books and watching his DVD's I do not see this covered in detail except to "wrap around it." But how would that be possible if you have a post right in the middle of the floor away from any adjacent walls?

Any experienced builders in this area, please feel free to enlighten me as to how you did it, or maybe I missed something really simple. Either way I feel that this is an important area to discuss because when I talked to a traditional builder about these types of structures this one one of the issues that they brought up. Suffice to say, they stumped me. And it is a point that many people get hung up on due to the idea that "wood in the dirt always rots". This would certainly help any other curious builders who have concerns about grey areas like these. Any input is much appreciated. Thanks.

So, if you know anything about Wofati and Oehler structures they follow one rule; "Work with what you have"

If someone has easy access to steel beams instead of wood, use that as posts. If one has easy access to billboard plastic, use that. If one has easy access to flat land, build on that. Well I found several huge roles of woven polypropylene highway fabric. (note polypropylene it is not the same as polyethylene but a very similar substance) I am sure you have seen this stuff somewhere at some point. They use it under the road when pouring pavement, When I saw it, and saw that it was abandoned after they used several roles to make a roadway, I was ecstatic because buying polyethylene sheets is definitely not the cheapest part of the job. However upon further investigation I found that it was different in some ways, and most importantly it is WOVEN. so if you hold it up to the light you can see the light escaping through, and of course when you pour water on it the water can seep through. The main reason we use poly sheets is as a sort of water barrier. so I wanted to ask you guys about this situation and see what you think. Is there any way I can use these sheets in construction? Heck, is there any way I can use them if I cover them in some sort of paint? What do you think of this situation? or am I just better off buying polyethylene sheets?

Jason Vath wrote:Update. It's on baby!

Thats Awesome Jason! I am currently Trying to build a similar structure by myself, and the excavation process is taking much longer than I would have hoped... Please keep posting pictures of the process, And I would like to contact you directly because I am struggling with some of the specifics, like the floor moisture barrier and roof post notching.

Where is this at? it reminds me a lot of Oehlers ridge house.

Trace Oswald wrote:Mike's book and videos explain all those things.

They do explain much of the process, but some areas remain sort of foggy. Perhaps I will just have to derive what I can from intuition, or the "great potato" as mike calls it. But seeing a picture or video of some of these details would really help in construction, especially the small but important details such as the post and floor polyethylene interaction, notches, etc.

Glenn Kangiser wrote:

paul wheaton wrote:
I was about to tell you off because the word of "some guy" vs. the word of mike .....  and now that I see how much experience you have, I'll assume the position of "silent pie hole"

Do tell - what have your experiences been down this path?!!!

I have browsed that thread several times.  Sometimes I read all of the pages and sometimes I just look at the pictures.  But that is, no doubt, an excellent thread!

Whitlock is my buddy and neighbor.  I am "some guy."  Whitlock is doing his own project now too.  Glad I'm not the only crazy person in this area.

I think Mike had experimented with the charring and plastic bags and maybe been successful in his case.  The charring would likely work out better without the plastic in some cases.  In my case it failed. 

For one thing I had wet logs for posts.  The logs when held vertically dripped water from the wood.  I am sure this collected in the bags and was recycled within the wood.  They were also next to the uphill patio so may have gained a bit of moisture from there.  As another mark against them, we are in porphyry clay which is hard and dry ... a claystone preventing surface water from penetrating the ground for the most part, but when it does get into a hole in the clay, the water will stay there for months, sealed in it's own pocket as the clay swells slightly and seals off all exits.

It could have worked better with totally dry wood IF moisture never got into the bag with the wood, but that is hard to insure.  Once it is inside the ag it becomes a terrarium recycling the moisture until the wood is totally rotted and turned into mush.  I found some nice big pine beetle larvae happily munching away inside the bag area.

I jacked up the beams and cut the bottom rotted off post with a chainsaw and fabricated steel bases for the three posts lagging them to the bottom of the post.

I don't view my experiences as detracting from Mike's pioneering in this field.  Just as further research and a continuation of the work Mike started.  I owe him big time.

One thing that might be possible is painting the WHOLE post in polyurethane and then sinking it into the ground. I thought about wrapping it in polyethylene but if that got punctured the whole thing would be like that trash bag.

I'm posting in hopes to learn more about the Mike Oehler PSP formula for building underground houses in Appalachia.

I've looked through an older copy of his book from a local library, but I feel like I am missing some information just reading the book. I want to get my hands dirty by building a small version that might be 10 by 10 feet. Maybe I'll hit a few walls, but I'd like to try it.
My goal is to learn enough so that when we build a larger version we won't make any serious mistakes.

So I am reading his books and going through his workshop videos. One trouble that I am having, however, is being able to visualize some of the designs. Specifically the initial PSP structure and how these would be built into the floor polyethylene, how the walls would be built up, and perhaps most importantly how exactly to notch the posts and set the roof. I know that if they are in the wrong direction it would enable the earth to cause the whole structure to lean… I know that many of these things are in the book, but I am coming here to see if anyone has photographs of construction in progress following the PSP method or even videos? Especially the minute parts of the construction and details.

Thanks for reading!

Sorry to revive this old thread, just wondering if anyone has had any luck with finding Oehler's exact imagery or diagrams detailing precisely how he notched his posts and girders in his PSP structures? And are there any such pieces of information of the other processes, such as how he wrapped the polyethylene around the posts and under the floor? And packed in the walls? I am finding it hard to see the specificities of his work. Though his books are useful, there is much as general ideas. I assume If i just used general ideas, or even incorporated other designs that aren't quite the same as his, I may have a few problems here and there.