Mike,

As I understand it, you have a great deal of experience with using softwoods such as pine or fir in your construction due to availability. Here in Missouri I have a lot of hardwoods to choose from, and really only 1 softwood, that being red cedar (and not in large quantities). In all the homes that you have seen built using PSP, have there been any particular species to stay away from? Have you seen the use of any one particular type of tree lead to a failure of any kind?

Is it really wet in your area, Quittrack?  I know red cedar is fairly rot resistant.  What kind of hardwoods do you have over there?

We get around 30-40 inches. Officially the average is 36" but the last two years its been closer to 40.


Oak (red, white, swamp, etc), Hickory, Maple, Elm (doesn't get very big before the blight gets it), black locust, Honey locust, Osage orange, Poplar(cottonwood), Walnut, the occasional Cherry, rarely we might even find an ash tree.

By and large the cedars around here are more of a scrub tree. The soil conditions aren't right for them to grow tall and straight. They're usually pretty squat and fat little trees unless they were planted as a windbreak years before. But since they have absolutely no value locally, they're not terribly hard to find and you can have them for the taking. Usually the stipulation is that you have to take more than you want...

I have heard that osage orange will last longer than black locust, but I wonder if there might be some ickiness to having it indoors with you.    That would make me want to prefer the black locust.

It definitely has its ups and downs. I don't care for the smell among other things. It out gasses a kind of creosote type smell that I just don't find appealing really. I'm burning cutoffs from some fence posts that we estimate were cut before WWII, and they still smell that way, even though the first 3/4 of an inch is soft, the centers are still hard as a rock, and they burn so hot I sometimes worry about warping the grates in my wood stove.

I have heard of several wood stove makers putting warnings in their manuals about osage orange.  Hard as a rock, yes.  Burns hot, yes.  I would take a look in that manual for your wood stove.

As far as PSP, I would say Black Locust if you can get your hands on it.  One just fell in our front yard.  Gotsa buncha them licorice ferns in it.  They taste good and all, but I have a question.  Is that a sign of a dying tree? 

Any arborists on this site?  I would love to learn more about tree analysis and assessment.

I wouldn't build with birch. Can't say about the others you have been talking about since my experiance is all with soft woods. Ask local farmers what they use for fence posts.

How are the soft woods holding up, Mike?  What is the main purpose of the charring?  Are there any soft woods you would say work better than others? 

My impression is that black locust is the most famous for fence posts.  Farmers would call it "stone wood" because it would last longer than stone.

Locust and Cedar.  When people drop fences into the ground, they usually fill holes with concrete and let the post set, right?

With these so called "rot resistant" woods, would you still do that?

Mike, I know you are not a fan of concrete, but have you seen or worked on a PSP, or rather, Earth Integrated Home that did pour concrete for the posts?  Did it work any better than the plastic bag method?

Around here, historically, the osage orange is the hardest, most long lasting. It has its downsides however, in that it smells pretty strong, is harder than the hinges of hell, and doesnt exactly grow straight, leading to a lot of knotted, twisted pieces that aren't really workable as a post of any length. I guess its so dense that it's own weight carries it over in a bow shape a lot of the time. 9 feet is hard to get a straight piece.

Locust is hard, and rot/insect reisitant, and likely what Im going to use for any posts that are in questionable locations. I'm not fond of their thorns, but there are farmers around here that would PAY to get rid of them. A little known fact (putting on my Cliff Clavin hat here) about locust is that they are a legume (nitrogen fixing) plant, so they are useful in a lot of different ways besides posts.

Cedar, lik I've said, doesnt grow very tall around here, so posts wuld be fairly short. I do love the smell of cedar, and its a beautiful wood. Not sure about the particular strength of it though, as its fairly lightweight... I'll have to research strength.

If I do things the way I plan, they will be sitting in relatively dry soil anyhow, but rot resistance is a bit of a concern as most things in life rarely go as planned.

My primary concerns are strength related, to stretch my spans as far as possible without worrying about failure.

Yeah, the last thing you would want is your roof caving in on you while you sleep!  Strength first, then deterioration.

Yo Steve and Quittrack and other folks interested:
Hey guys, it is 5:30 pm and I have been up writing since midnight (with 4 hour nap qnd 4 hours firewood and household chores).  I'm working on my next book which is only likely to get written in the cold months since the warm months are building months. Most of the questions you have asked ar in The $50 7 up UNDERGROUND HOUSE BOOK, THE DVD (VIDEO) SET and The Earth Sheltered Solar Greenhouse Book. I simpley can not answer the same questions again and again to hundreds, thousands, or (God help us) hundreds of thousands of people more. The question about collecting rainwater off a PSP roof was good and unanswered in  my writings and videos to date (wiill be later) so I have answered it on this forum. Will do my best otherwise. -- Mo