Glenn's Underground Cabin Update

[PureCountry]

Does she run around all day like that while you work on the house? 

[glenn kangiser]

The reason Sassy hates it is that that is not a pix of her, although her beauty rivals that of Batgirl.

Jeesh -- hope I talked my way out of that one.

[considerations]

Don't fret too much Glenn, flattery will get you almost anywhere.

[glenn kangiser]

I keep trying....

[Bishopknight]

Hey Glenn or anyone willing to help,

After reading Mikes book several times and reading about your amazing progress, I'm considering building a PSP house myself on my land ( pictured below ). However, everyone I know thinks this is a bad idea. A terrible idea in fact. But I'm still highly considering it. I've never been one to follow with conventional thinking.



Maybe you can allay some of my primary concerns about building the Ridge design featured in his book.

1. Does my post installation method sound ok? I would dig a 3-4' footer hole for each post, lay and level 2 solid concrete blocks, then wrap the buried part of the post with polyethelene, lower it in with the backhoe and backfill it. ( I did this with my entry gates this weekend and you would have thought I cemented them in, theyre rock solid! )



2. Moisture... I leveled my lot against a south sloping hill. I have a feeling if I make a moat per-se on the north hill side around the house and drain it all down hill, I shouldnt have any moisture problems as long as I shed rainfall away from the house as well. Do you agree?

3. Frost Heave: If I started before the end of the year, could the posts I plant possibly be frost heaved? That may make me hold off if its the case.

4. Cold floor: Putting carpet ( on top of poly ) right on an earthern floor doesnt seem like it will be very warm. What do you think of the idea of putting 2 inches of dow blueboard then 2 inches of dirt or sand on top of it?

5. Seasoning the wood: I just cut some 30' , 12" hemlock that could be used as a girder. Do I need to let it season or could I use it before years end without too much risk?

[glenn kangiser]

I forget where you are at, BK.

You will not find many who think it is a good idea because most of them know nothing about it and have never done it.  They are just going from their own gut reactions gained from conventional building knowledge which is not worth much when applied to the PSP method.

1.  I found that the poly wrapping the post at the bottom and buried keeps moisture in the wood drawing big hungry bugs and decay.  The bottom area about 6 inches above and below gtound will be attacked at a minimum.  Fungus sends out tendrils and actually draws moisture into the wood to decay it.

I know Mike O. recommended it but I found that in practice it only lasts a few years on untreated wood.  I would say I started noticing problems in about 3 years.  Hemlock is usually pretty fast to decay.

2. Mike now recommends an EPDM roof membrane.  Ideally take it about 10 feet out past the building.  Moat - uphill patio on the high side to drain water off before reaching the house, yes.  Get below the top soil to the mineral soil - this will eliminate a lot of seepage.  I would suggest French drains and posts pinned on top the floor of the excavation over a couple inches of concrete and a vapor barrier under the post area.  I have had no problem with posts done in this manner but temp diagonal bracing is req'd before gentle backfilling - no machine tamping.

Rainfall over soil draining down hill off of the house also - yes.  Use dormers, other methods per Mike etc  on the low side to divert water around windows or doors.  Mike wants to see light from all four sides of the house.

3.  The ground 6 to 10 feet or so down where the post bases are should not heave.  It's generally warmer underground.  Check out Lodestar's postings also.  He did the PAHS system up north - Minn?

4.  The earth floor should be plenty warm - the cold is mostly associated with the air outside and above the underground house.

5.  I wouldn't worry about seasoning.  The house can move a bit wth no problem as the wood dries.  The logs will drain water a bit after cut and placed on end - another reason for no plastic.

[Bishopknight]

Hi Glenn,

I'm in Maine, Oxford County.

Thanks for answering all my questions.

I found in Mikes book where he suggests "charring" the posts as a means to preserve. Sounds labor intensive though. ( make a campfire and lightly roast the post ends until black?) Have you tried that? I wonder if wrapping the posts in garbage bags after charring would be ok. Otherwise, I agree with you, just put them in a post hole, add gravel and some concrete blocks to sit on, then backfill... but why gently?

I'll probably use some 12" galvanized spikes for mounting the girder to the posts. I tested a 10" spike out on saturday and that sucker held 2 logs NICELY!

Most of all, there is something exciting about doing this stuff, its addicting

[glenn kangiser]

Charring the posts only makes the bugs think you brought them a barbecue lunch in a plastic bag.  I did that too.

I would suggest getting 1/2 or 5/8 rebar and cutting it into 16" lengths and using it for nails.  Drill a hole same size as the rebar with a 16" ship auger using a heavy 1/2 inch reversing drill - clean the chips a couple times with the auger - drive the rebar spikes in with a 4lb or so hammer - it will be tight and it will not come loose.  I try to drill to get about 8" in each log.

I would suggest not putting the posts in a hole-- drive a 30" to 3' or so 5/8 or 3/4 rebar spike into the ground leaving about a foot above your floor grade.  Depends on your soil - mine is like concrete so I had to use a jackhammer to do that. 

Backfill from each side carefully to keep from making your house crooked.  Believe me-- you don't want to try to dig that out by hand after pushing the building sideways.  Work one side a bit then the oppossite side to keep it straight -- don't over excavate if you can help it -- just more loose weight to push the house sideways. 

Be prepared to accept rustic tolerances.  - They will show up and who ever saw a tree grow totally straight anyway? hmm

[glenn kangiser]

A couple more views of the subterranean shop.  Note that these poles (bottom) are placed on pins drilled into the ground with a rotohammer and drilled into the pole bottom to keep them in place.



The tunnel is visible in the  center  - yet to have the top covered and the piled up earth removed from it.

I'm going to use it to get up by the pool with the Bobcat for a final bit of earth moving and leveling for the roof and Hot Tub area.

[Bishopknight]

Interesting.

I see, so you are somewhat advocating an above ground pole barn type of design with the spikes holding firmly the posts in place.  Obviously the weight and backfill will prevent it from shear loads.  And then a little gravel between the post and the ground should prevent rot to a lesser degree. Then the normal psp methods probably apply. 1 1/2" thick boards on the outside of the posts with polyethelene on the outside of those, correct?

btw, thanks for your help,
BK

[glenn kangiser]

Yup, that could describe it.  Earthquake bracing is provided by the backfill as you say.  That prevents a portion of the post from being underground and rotting - shrinking in length as the bugs eat the bottom.  This was a later option mentioned by Oehler and used by me as my ground was solid rock in many places and the rest was very hard claystone.

The only posts I had a real problem with rotting off was the 3 that were buried 30" or so charred and wrapped in plastic-- they rotted off and bugs got them, so I recommend the pins and temporary bracing until backfill is installed.

The gravel or fairly dry packed concrete for full bearing of the post even if a bit crooked- set the post on fairly dry mixed concrete over a piece of plastic to prevent moisture wicking up through the concrete.

I would also recommend the French Drains going gravity out to daylight on the low side.  I didn't do much in that regard but it could have prevented one moisture problem I have in a corner.  If I had religiously followed Mike Oehler's instructions I likely would not have had that problem but I was aware it was a possible problem when I did it and didn't consider it to be major.

[Redoverfarm]

Yup soil and wood in direct contact with each other is a bad idea.  Probably been better off to put a PVC sleeve around them and seal off the top to keep water out.  Big post require a big sleeve like a 18" water or sewer pipe.

[glenn kangiser]

I don't trust any plastic around posts.  Moisture stays in there like a rain forest or terrarium n being recycled back and forth through the plastic walls, and if fungus starts to grow it will drag water in if there i any earth contact.  I'm a chicken now. 

. 

I think the water that got into my plastic was from the logs themselves.  They were rather green and since then I have noticed that water actually runs out of the end of the logs after cut and stood on end when green.  The area they were in was dry yet all 3 rotted even when they were not exposed to moisture.

[quittrack]

Hey BK, I'm having that same issue with "unconventional thinking."  I'm looking at a PSP design myself. Problem is Im in northern Missouri so we have very wet weather (especially this year)

Glen, I've been watching this thread for awhile. Love the pictures! I'm sure I'll pick your brain a lot as this idea moves forward.

[glenn kangiser]

to the forum, quittrack.  Glad to have another of us here.

Are you in hilly area there?  This can even be done on the flat if you berm it and make drainage around it.

[quittrack]

I was leaning more toward a hilltop and make sure I have enough overhang on the poly and french drains to make the water go away before it has a chance to soak in. I'm putting a LOT of emphasis on the drainage. So much so that I'm planning to build above grade and cover. ranther than cut into the hillside.

With 36" of precipitation annually (this year more like 50") I have to worry about the water table being that high sometimes. So I'm planning on digging a trench all the way around the site and burying gravel and plastic drain tile a few feet below grade to give myself some relief if the water table gets too high. In essence I have to plan for flooding, whereas several of you others don't. In Maine, I'm assuming that you have the same sort of issue as myself.

The benefit that I have is lots of access to local hardwoods.

My dad had some swampland cleared of trees and the logger that did it made a nice neat pile of maple trees, about 16" in diameter and 45-50 feet long. Our hills are covered in red and white oak, occasional black walnuts, black locust, osage orange, and a lot of what we call swamp or burr oak. We also have an inundation of smallish cedar trees that get as large as 14 inches at the base, but are viewed as more of a pest than anything else (extremely prolific). As you can see we have no true softwoods besides the cedars, and most of them dont grow large enough to be used for anything much. I've also been told that the red oak is no good for this particular application because they smell like urine in a closed environment. In short I'm long in hardwoods and would be able to use woods that a lot of you would drool over, simply because we have an excess of them and normally burn them for firewood. Well we look at clean pine lumber that way here.


My particular building site is primarily red clay and what we locals call "white oak" soil (the oaks have stripped most of the surface fertility out of the soil so there's only a few inches before you hit clay, and its pretty hard). Other than maybe brickmaking or terra cotta pots, this soil doesn't have a lot of uses.

I'm on part of my family farm (4 generations) so resale doesn't matter at all.

Im thinking for posts, after reading what you guys are saying about rot and insects, that I'm going to bore holes and pour piers to set my posts on, that way I can minimize my contact with the earth as much as possible.

Hope I can learn a lot from this forum.

[glenn kangiser]

Check out information on Osage Orange.  Nearly unable to be destroyed.

[Redoverfarm]

Sort of like Locust.  Some fence post have been in the ground for years exposed to the elements and they are still solid.     

[glenn kangiser]

I think Osage could be an answer if you still wanted to bury some or all of the post bottoms.

[quittrack]

Check out information on Osage Orange.  Nearly unable to be destroyed.

lol

Nearly unable to be worked with too

Osage orange has kind of a limited natural range so not a lot of people come into contact with them. On the west coast I'm betting you've never seen any up close. The wood does have its advantages, but there are a couple of things that work against it to make it it unsuitable (at least ot me) for this type of application.

We cut it for fenceposts around here. It will last 40 years in the weather if you are lucky so I'm not worried about that. It has a beautiful yellow colored heartwood, and a hardness of something between steel and granite. However, it has three or 4 points against it, for me.

The first is the odor. The reason the bugs don't like it is the resin it contains is kinda noxious. This same tree produces a fruit that around here is either called an osage orange (tree's namesake) or hedge apple. I don't know what they contain chemical wise, but they're used as a kind of natural pest repellent.

The second is the previously mentioned hardness. This is the hardest of hardwoods. I once cut a trailer load of posts when I was young and stupid. Using an 038 Stihl (I think) it took something like three minutes of HARD cutting to saw through an 18" post. After two of those, you have to stop and sharpen your saw.

The trees (at least around here) are squat, ugly little trees with nothing straight over 4 or 5 feet long. I guess its the weight of the wood, but they tend to bend down toward the ground when they get any height. I am personally growing a small grove in a secluded back corner on the same farm which I am pruning in the winter to ensure straight growth, but they are just saplings. And I'm not talking about a slight bow... Im talking a 9 foot section doing a complete 180 degree turn. Might be cool for an entranceway arch or something like that, but by and large they are just too crooked for most applications for me. Sorry, I like (somewhat) straight lines.

They have thorns. (need I say more?)

Being so hard and dense has made them somewhat brittle. I've seen them used as piers for a small bridge, and all of the posts that carried weight split from top to bottom. (now granted I don't know how much weight the bridge carried at any one time...) The have AWESOME lateral strength, but don't carry weight too well up and down. I guess they're just too hard to be flexible once they dry. That is my primary concern actually. I can work with something that is difficult to fabricate (hell, this house is difficult to fabricate), painful to work with, and a little strong to the nose (although it does keep the bugs away), if it weren't for that splitting. Im sure if I looked long and hard enough I could find suitable posts in straightness and size to use, but that bridge just keeps popping into my memory. I wish I knew whether the splitting was caused by compression, or just by lateral flexing due to uneven pressure because that might make it a different case altogether...

But the story changes a bit because Black locust (commonly known as the 2nd best post wood) posts were used to replace the split osage a few years later and it lasted until the bridge was replaced altogether by a concrete and steel structure some 20 years later.

I dunno... sounds good on paper. The old timers around here tell me that it isn't suitable for structural members, and all seem to have a different reason why. I think they were just told it wouldn't work by their fathers years ago and just assumed the reason later.

[glenn kangiser]

There are only a couple Osage Oranges near me obviously imported by the old timers in Gold Rush days.  They were so odd I studied up on them a bit.  Apples that look like green brains.  I have found the thorns.  It has the ability to be a vine of sorts in hedge rows or a tree if out more by itself.  It was used as impenetrable fence before barb wire and some say it was the inspiration for barb wire.

Splitting a lot of times doesn't weaken the post - the strength is in the cross sectional area.

Don't put a lot of faith in stories of what is suitable for structural wood and what is not.  In general, most wood if kept dry will remain as sound or sounder as it was green, I find.  I find more  that it is what is considered as commercially suitable for structural is what they are talking about without knowing it.  Not what is fine for rustic building.

The bull pine around here is spurned by early everyone who doesn't know the truth, but I found it makes the best trailer bed boards by those who know and I found a barn that is about 100 to 150 years old built entirely of it according to the rancher who owns it.  So much for the un-knowing's assumptions and stories.

[glenn kangiser]

Got a bit more done today.  Set a treated bridge timber for holding a rammed earth floor.  Not enough money for concrete and an earth floor is fine for under a lot of my tools such as the press.  I need to move the big lathe into the shop in the morning.

Behind the bridge timber will be an open gutter.  Later I may fill it with gravel for a French drain but for now I will leave it open.



I drilled through the timber then rotohammered into the rock and claystone  to fasten the timber to the ground at grade level on the top.  Inside it will be filled and compacted to grade so the tools will be on the dry surface well  above the water drainage around the edges in the gutter.

I have an existing French drain to daylight around the older part of the shop that the gutter will tie into as well as having it drain out to the east also..

[Bishopknight]

I just found this link to a free online version of mike oehlers, $50 and up, underground house book. Don't know if he authorized it or not though.

http://www.scribd.com/doc/5702329/-underground-house-book

If you like the book, please purchase a copy directly from Mike!

[glenn kangiser]

I would encourage not just the book, but his videos also --if you are serious.  He goes into a lot of hints , detail, instruction and things not included in the book also. 

I mean, crimoney -- you're getting a whole house for $50 --- It couldn't hurt to spend a bit more to learn more about how to do it properly.   

I have had about a half dozen requests for me to write a book in the last 6 months, going into further details on this.  Latest request a couple days ago.  I keep thinking about it but haven't got past research on how to do it and the start.

Yesterday I brought in the fill to get the floor back to grade after removing the giant boulders and claystone with the jackhammer and Bobcat.

I wet it down for a start on compaction.  This morning I raked the top smooth for the compactor and put the rocks from the top into the French drain gutter to help keep it opened and to be easily removed if necessary.  The big rocks I tossed to the side for walls - the support behind th pole etc. between it and the ground (In case I accidentally bump into it with the Bobcat... me?



Above is the Harbor Freight Plate Compactor which I have used in a lot of places and am quite happy with -- B&S I/C engine.  It was $599 when I bought it. 

[glenn kangiser]

My miner friend came over and helped me get the lathe unloaded from the trailer and into the shop yesterday - we drug the press out to the fairly well compacted corner where the plate compactor is above.  It will be easy to use there and does not require a concrete floor.

The lathe is about 2 feet longer than I thought.  14 feet long, it goes clear across 1/2 of my shop concreted area.  I guess I will put it at an angle to make it usable and give me room to walk around it.  Still repairs to make on it too and figure out a motor for it.