Psp materials

Paul and I just watched this awesome video on psp structures (underground shelters).  We got to thinking about the best woods to use for the poles, girders, roofs, etc.  Mike Oehler lists a number of conifers in his book.  Would Western Hemlock work?  How about (my new favorite tree) Black Locust?  Rot resistance is important.  Anyone have any experience with psp?

There's a great question:  anybody here actually built PSP?

Gentlemen, gentlemen!

Please do not start conversations in the middle.

What is PSP, and what do those initials stand for?  What was the title of the video?

Sue

Susan Monroe wrote:
Gentlemen, gentlemen!

Please do not start conversations in the middle.

What is PSP, and what do those initials stand for?  What was the title of the video?

Sue

Hmmmm........I have to agree.


But, black locust has good rot resistant, and is in fact used for fence posts.

Hemlock would rot out in no time.

Psp stands for Post, Shoring, Polyethylene.  These are materials required to build an underground house.  The video was called Combined Underground House Workshop and Shelter Seminar.  I think we got it from undergroundhousing.com

Black Locust is looking more and more promising.  How about Western Red Cedar?  It is rot resistant, but softer than Locust. 

A guy at my local lumber yard says cedar will still rot, esp if it can't dry out.  Wet/damp cedar = rotting cedar.  He also said that these days, cedar is harvested as soon as the trees are of a commercially viable size, and the oils really haven't formed as well as in older-growth cedar, so they don't last as long.

It might have been Paul that said the old-timers would set in black locust fence posts, then pull them up 40 years later, reverse them and stick the other end in the ground for another 40 years of use.  So, you might be right.

Sue

I read somewhere that a big part of keeping the wood from rotting was charring the outside. sorry if that has already a been brought up. are there any other natural treatments to prevent rot? anything that prevents the microorganisms that break down the wood from finding it appealing ought to work. what about changing the acidity? vinegar or citric acid soak?  cedar oil?

some wood has rot resistance but there is nothing that is rot proof. for me a home isn't a home without permanance................ or is that permie-nence.

The Aussies are so termite-conscious that they tend to think that nothing is permanent except concrete.

Sue

Who wants to look at concrete all day long?  I've heard that concrete is not permanent. 

I wonder if there is a periodic maintenance procedure that one could do to perma-fy their psp structure?
Add cedar oil?

Good ideas Leah and Sue

I guess in the big scheme of things nothing is permanent. I guess the better term would be indefinite. ok here is a wacky idea. a plastery/composite/concrete/glass like (details yet ot be determined) that  has staying power  in a poured/plastered mold shaped like an igloo. dig a hole the size and shape of the "igloo" and then plaster on the mix  (thickness to be determined by strength tests). after it dries pull it up, re shape your hole to fit the foot print possibly pour a foundation and drop it in. bury it as much as your plan requires. 

differnet domes could be connected for different rooms. each would have incredible strength architecture wise and could be assembled on site. materials would have to be carefully chosen but I'm sure could be worked out. something light weight would be nice. hmm some natural form of styrofoam.....don't forget to  have all windows , venitlation, doors and plumbing, electrical openings worked into your mold as well as places that boom truck could attach to if it is heavy material or very large.

my favorite idea yet.

That sounds like a combination of sandbag building and straw bale building.

It wouldn't be all that ecologically sound, but you could always cover styrofoam blocks with concrete, and embed stones to kill the concrete look on the side that would be a face (inside or outside wall).

Concrete is as permanent as building materials get, I think, esp where it touches the soil.  The Romans invented it, and some of their viaducts are still standing.  I think some of them are still in use.

Sue

Oh, I just remembered...  there is a method of concrete construction that uses large, inflatable, reusable bags as a form.  I think the concrete foundation is poured, the bag is inflated on top of the foundation, and concrete is sprayed (?) onto the bag.  Once it's set, the bag is deflated and removed.

Concrete is as permanent as building materials get.  It was invented by the Romans, and some of their viaducts are still standing.  It can be pierced, stained, carved, and mosaiced.

Sue

like a paper mache (sp) house! that is cool I hadn't heard of that susan. I didn't  know that concrete could be sprayed that would even simplify the construction and it could be easilyused for above ground housing too. an apropriatly shaped durable blow up frame could be used over and over. I think that the aesthetics  issue with concrete could be over come. it can be colored and have designs imprinted on the side. I am seriously considering stained concrete floors if we build a home, I like it better than tile.  I see a dark brown earth colored bit of dome with some windows sticking out of the earth and a small patch of grass on top watered by the aerobic septic system (would dry out too fast otherwise). if it were a home for myslef it woul only be partially under ground. a hillside house. I'm going to have to draw a picture now 

Leah, here's your igloo idea (kind of) in action:  http://www.popsci.com/gear-gadgets/article/2005-11/grancrete-llc

And here's a site on spraying concrete onto an inflatable AIRFORM http://mike.texasdomes.com/category/dome-construction/

And see what an artist can do with concrete at Flying Concrete: http://www.geocities.com/flyingconcrete/

This isn't your grandfather's concrete.

Sue

That is pretty impressive.  I suppose concrete's not so bad, if it's artistic like that.  Have the posts for the underground house in sunken concrete, but shape a table or a stand of concrete above the ground and have them connect. 

What if you were all the way underground but just dug out more earth around the house?  More light getting in the house, a space for a garden, space for a greenhouse. 

thanks for the links! that is some pretty cool stuff. the concrete techniques/technology have gone farther than I thought!

Using concrete for the PSP...

Instead of embedding wood posts in concrete in-ground, make posts of concrete with any attachments built in.  They have cardboard tubes at Home Depot just for that.  But if you bought one or two of those turquoise plastic pipes that are used for sewers or something, maybe you could cut them in half lengthwise, strap them back together after coating the inside with a mold release, fill with concrete and let set, then remove the plastic pipe casing.

Just a random idea.... 

Sue

super idea! I was just tossing ideas off my dh yesterday (much to his dismay) I was trying to get an idea of the weight of a given volume of concrete adn whether some of the truck cranes he has at his disposal could handle a concrete wall. I was thinking of a form for a wall that is 10x9 and about four inches thick reinforced with rebar. tapered at the top (so its wider and more stable at the bottom) something to set partially underground. I know that is not a new idea but I would feel better about concrete underground than wood.

Try investigating lightweight concrete.  I will be doing just that when I have some time and no freezing weather.

The standard concrete is Portland cement + sand + water, and possibly some liquid additives to prevent water migration.

I bought some Perlite to replace the sand, and I'm considering adding some Diatomaceous Earth to fill in some of the smaller gaps.  This should be substantially lighter than standard concrete.

Normal concrete tends to weigh around 150 lbs per cu ft.

'Normal' lightweight concrete weighs somewhere in the 105-115 lbs per cubic foot.

Experiments, experiments.....

Sue

Oehler recommends wrapping your posts in thick plastic garbage bags and tying them off.  The important part is careful backfilling with the right dirt constituents (no rocks, sharp materials).  His has been going strong for over 22 years. 

I know, 22 years is nothing compared to the Roman Coliseum!

I am a wood guy.  I have a new appreciation for concrete thanks to Susan, but I would much rather have my house be built with wood.  Sit in a log cabin with wood furniture.  Then sit in a room with concrete ceiling, floor, and walls.  Then tell me which one makes you feel better.

Wood is extremely attractive, aesthetically speaking.  There is simply no denying that.

And if a person is prejudiced toward it, there's no denying that, either.  Wood is nice, wood is beautiful, wood is easy to work with.  But it does have a few drawbacks.  If you can overcome the drawbacks in a realistic way, they become moot.

Sue

A lot of folks do underground stuff with cement. 

PSP uses mostly wood.  I think the idea is to use materials that are easy to come by for certain areas.  If you have forest, you have most of the materials for a PSP structure.  Therefore, you could build a snug, bright, home for peanuts. 

Oehler has been living in his first PSP home since ... I think 1971.  So ... 37 years?  His total cost for that first home was $50.  You might think that's a joke, but the logs came off his land, the wood ends were throw away ends from the mill, throw away windows, throw away doors, and a bunch of black plastic.   

We have now watched six hours of this PSP video stuff.  Amazing. 

I can see why the conventional underground homes are expensive and problematic.  And I can see how a little wisdom can save a lot of money.

When it comes to building eco, I really wonder if this technique might not be the most superior by far.

I think it is the most eco-friendly.  This is a permies site.  If the wood is on the land, use it (ethically, of course).

How do the local building permit people feel about PSP?  Can you get permits to make a home this way?

They're so finicky in some ways, and lax in others.

Sue

Good question about permits.  Dunno.

I know that some folks talk about that whole 200 square foot thing.  Anything under 200 square feet doesn't need a permit.

there were folks who built psp somewhere in europe who didn't get any permits.  When the permit requiring dudes heard of this, they went to check out the site.  They couldn't even see the house!

Good camoflauge is the answer to this, really really really good camo. 

I have the paper from the building permit place in Oly, and it says the 200sqft rule only applies to NON-living spaces.

"No, no, it's just a root cellar."

Sue

"With couches and a dining table in it."

I want to bring this up again, now that there are some more folks participating in this forum. 

Are there woods that work better for posts, roof beams, etc.?

It seems like the rot-resistant (even though they aren't ALWAYS) woods would be good choices, but I know Red Cedar is relatively soft. 

Hi Steve

Australian Eucalipt is the timber you want, if you can get it over there, hard and very slow to rot damm near impossible to rot if kept dry
Blue gum or Iron bark would be the ones to try locate, unsure how many gums have made their way to USA

Bird
Greetings from Aus.

Never put the posts in bags a bury them they will rot for sure.
Cedar and red wood are  the most rot resistant but not the best for structural suport.
Keeping the wood dry is the main thing.
I have built this way and have a friend that buit a huge house using the psp system.
I will see if I can get him on board.
But for now here is his place-


http://countryplans.com/smf/index.php?topic=151.0

Paul, did you ever ask Mike what kind of wood he used for his structure?  I'm guessing since he used what he had available on site that it's probably pine, spruce, or fir -- and it seems to be holding up quite well.  The trick is to keep it DRY!  Dry wood doesn't rot.

Bird, there are some eucalyptus trees in California (quite a few, from what I've heard), but most of the United States gets too cold in the winter for the eucalyptus to survive. 

Kathleen

I have used a few eucalyptus in my underground cabin in California, and have found that they are very strong, but are subject to attack by powder post beetles after they are dry.  One of the beams resembles swiss cheese.  They don't seem to attack all equally though.  This was E. Rostrada ?  - one of the common Ca. species.

Nailing is nearly impossible without drilling after they are dry.

some Australian info on powder beetle

http://www2.dpi.qld.gov.au/forestry/5035.html

it seems if you use bee's wax or some such product you reduce the risk.

Kathleen Sanderson wrote:
Paul, did you ever ask Mike what kind of wood he used for his structure?  I'm guessing since he used what he had available on site that it's probably pine, spruce, or fir -- and it seems to be holding up quite well.  The trick is to keep it DRY!  Dry wood doesn't rot.

Bird, there are some eucalyptus trees in California (quite a few, from what I've heard), but most of the United States gets too cold in the winter for the eucalyptus to survive. 

Kathleen

there are many cold climate gum's, not all are hot/temperate weather trees, but local timbers would always be best in my oppinion

Thanks, Bird.  That was interesting.  The pictured beetle seems to be the one we have.  They have slowed considerably but eight years later we still see a few and it is really dry also.

It was a trunk section about 12 to 14 inches dia.

Whitlock wrote:
Never put the posts in bags a bury them they will rot for sure.

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?!!!

Whitlock wrote:

http://countryplans.com/smf/index.php?topic=151.0

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!

Kathleen Sanderson wrote:
Paul, did you ever ask Mike what kind of wood he used for his structure?  I'm guessing since he used what he had available on site that it's probably pine, spruce, or fir -- and it seems to be holding up quite well.  The trick is to keep it DRY!  Dry wood doesn't rot.

Better than that.  I was there when Sepp Holzer put up pictures of his similar structures and mike commented on what sorts of wood to use.  Mike and Sepp agreed with each other.  I think the only real difference between the two was that Sepp had used black locust and I don't think Mike had.

Here it is ....  Mike in the audience (next to some obnoxious giant) and Sepp up front ...



And here is Sepp and Mike and Mick:

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.

As to species, I did not have the species available that Mike mentions in his table for the most part.  After talking to him on the phone and reading his book several times as well as watching the videos and consulting strength charts, I decided it is all pretty academic. 

Don't let the species problems stop you.  I feel that nearly any wood you have will work... just reduce the loading.  You don't really need 2 feet of dirt on the roof.  Mike mentioned elsewhere that for temporary shelter even 6" of dirt will work.  From Mike's advice I decided on 18" max but have areas that are not that deep.

I was interested in this as my grandparents homesteaded in Oregon and used the Natural resources they had.  I use natural resources as well as what I call unnatural resources.... things given to me - used - recycled etc.  People love to donate to my underground complex and see material that would otherwise end up in a landfill be put to use.

I feel it is our God Given Right to be able to afford to feed and shelter our families.  While I am not a Bible thumper, God never told me it was necessary to ask permission to do that.  That is an inalienable right.