We just got our copy of Ben Law's book on roundwood timber framing, and we're feeling inspired. We had been working with the idea of ground-embedded pole frames, using pressure treated poles, most likely enveloped in a straw bale wall. The thought was that this would gain the strength and stability of an embedded pole structure, while keeping the nastiness of the pressure treated poles buried inside the walls. Law's book, however, is making us think about using untreated wood.
Where we will be building in northeast Georgia, there are zillions of acres of planted pines, so it should (in theory) be relatively simple and affordable to get a truckload of untreated raw pine poles. We're thinking of either doing an Oehler style charred and polyethylene bagged butt end embedded in a hole, or a Law style with the butt end resting on a stone plinth. Has anyone tried using such poles for construction? Any thoughts on their strength and/or longevity? Am I barking up (literally) the wrong tree?
I don’t know anything about Ben Law’s construction techniques, but I do know a little about “ground embedded” poles. My hay barn built in 1975 by a crew of young back-to –the landers is falling down, as every pole is rotten through and buckling. The butts were oiled, wrapped in plastic, and set in cement. In this case (and many other cases I’ve seen) it wasn’t the underground portion that caused the issue, it’s the soil/ air interface. I built a quick firewood shed about 15 years ago using western red cedar poles – these have since rotted and the shed is falling down.
I’ve since built a few barns and stay clear of any wood touching the ground. Here’s one we built last summer. Note the piers, all the wood is a minimum of 16 inches off the Ground.
Joined: May 04, 2010
Thanks for the information. I'm getting the strong impression, from this and other sources, that embedded poles are a short term option unless they're treated with something pretty nasty.
Several of the pole framing books I've read made the same point about decay happening primarily within 18" either way of the ground level ... higher or lower and the beasties that cause problem just are not there. One suggested treating that area of the pole specifically - perforating the surface a bit to enhance absorption, using penta paste (this was written some time ago), then wrapping with roofing paper type stuff. The suggestion was to do this, and periodically (every 10 years or so, if I recall correctly) dig down a bit and re-apply the treatment. Seems like it might be worth trying.
Mark Vander Meer
Joined: Dec 12, 2009
Is there some big advantage to putting poles in the ground that I am missing? The cost? Effort? Stability? Why not put the posts on piers? I will track down the construction book mentioned and see what they say.
Joined: May 04, 2010
The biggest advantage is stability, especially laterally. Compared to traditional reinforced concrete slab or stem wall foundations there also can be a cost advantage. There are also some benefits as far as ease of construction and adaptation to terrain. How relevant these advantages are, of course, depends to a great deal on the particular design.
Ben Law, by the way, does not use embedded poles - he builds rubble pits, on each of which a stone slab sits, and the butt ends of the poles rest on those.
Joined: Nov 21, 2010
Location: Mountains of Vermont, USDA Zone 3
About ten years ago (9?) I built an post and beam animal shed. I used the tops of pine trees from our forestry work as they were available and thus ultra cheap as in free. The posts were 6" to 9"(?) in diameter and planted about 3' or so into the ground. It was just something quick for use for a few years. I hadn't intended it to last.
Well, a decade later the shed is still standing, still rock solid and looking great. I am pleasantly pleased and very surprised. I expected it to rot out, especially those poles in the ground. It is in a winter paddock. There is deep bedding composting inside and around the posts to a depth of about 18" above the original soil level. It is a great place for keeping the pigs in the winter and growing pumpkins in the summer.
Would I do it again for a building that I meant to last? No, but then for buildings I want to last I build them out of stone, masonry, etc. Like our tiny cottage.
Experiences really do seem to vary. I find myself looking intently at the bases of utility poles I pass, checking for decay. I need to start checking for installation plates with dates when I'm out walking the dog - the wood preserving industry is claiming functional lifespans of 50-75 years (or more with periodic re-treatment of the area around grade level), but they obviously have a vested interest.
Joined: Dec 04, 2010
I note, when seeing wooden utility poles lying in a pile waiting to be installed, that about the bottom 6 feet have been coated with tar, as well as the entire pole being treated with some kind of chemical. I have a brother-in-law who works for a utility company on the west coast, I could ask him how they are treated. He has told me that they 'plant' the poles about 5-6 feet in the ground. Of course, these are not intended to last forever.
If you intend to use this material, I would suggest doing like Law does and install a drain field of rubble in the bottom of the hole. I would then install a large cardboard tubular concrete form, put the pole in place and fill the form, making sure the form extends at least 18 inches above ground and 3-4 feet underground, and at least 6 inches wider on both sides of the pole. Fill it to the top around the pole with the concrete. Leave the form in place and backfill.
Joined: Feb 28, 2009
Location: Near Klamath Falls, Oregon
I once cleaned for a couple who lived in a log house built of pine logs. Anyplace that water splashed on the logs, they were rotting away, and in one place had rotted clear through. The house was only about nine years old. This was in New Hampshire. Oh, and most of the rot was well ABOVE the ground; some of it was high on the walls, and the rotted-through spot was about four feet above the ground, three feet above the deck.
I would NEVER use pine for building anything that I meant to last, unless I could be sure of keeping it absolutely dry.
Here is my 2 cents worth... don't bury pine it will rot. Pine posts on plinths is a popular method here in MT. Most people put a piece of tarred felt between the stone and the wood to act as a vapor barrier. Kathleen is right about keeping it dry, lodge pole will turn to mush in few years if it is exposed repeatedly to water without a chance to dry out thoroughly. I have seen pictures of lodgepole structures called 'war-lodges' built by Indians here in the Rockies that are over a century old, and still standing/functional.
If I were you, and decided to go ahead with the buried post method, I would recommend using a rot resistant hard wood such as black locust. Save the pine for above ground. Good luck.
Joined: May 04, 2010
I think we may have put the timber frames on hold for the moment, and gone back to earthbag methods for our first outbuildings. As for the untreated pine poles, I'm thinking the best use for them will be as raw material jackleg fencing. Lord knows we're going to need a LOT of fencing.
Thanks for the input!
Joined: Nov 21, 2010
Location: Mountains of Vermont, USDA Zone 3
Where ever possible we use live trees and stone for our fence posts. Our soils are thin and the ledge is right there when you're trying to pound posts plus all the rocks in the soil. Trees can be there as fence posts for hundreds of years. We use them as the anchor points with long eye bolts so it doesn't hurt the tree. The wood continues to grow out around the bolt. Harder woods grow slower and live longer than things like poplar which are short lived and increase quickly in diameter.
Boulders are even better. They don't grow, move or die. Hammer drill time.
Joined: Feb 03, 2011
Location: SE Louisiana zone 8B
I am new here...been lurking a while and love this forum. I am a carpenter by trade and something you need to consider is what kind of pine you have: It comes in two varieties....yellow and white. The yellow tends to be highly resinous and resists rot better than white pine varieties. In the early days, it was used for masts on ships, log homes, and railroad ties. Certain varieties of yellow pine are considered pretty much a hardwood and are the main wood used for walk planks on scaffolding in our area. This link tells a bit about it:
Their are also other varieties of wood that are very resistant to rot and termites (another MAJOR issue)...most of the slowest growing hardwoods are very dense and hold up very well. Up north the best I've heard of is osage orange. Due to it's size though, those are only large enough for smaller projects like fence posts etc, but are reputed to last forever. Where I live now, my bets are on live oak...it will barely even burn.
Either way you go, keeping the wood out of the ground may be your best option. We are preparing to buy our own lumber mill and starting clearing some of the trees off the densely wooded portions of our property: We need pasture and for that the ground needs some sun. We have a lot of lobolly (Southern yellow) pine, gum, and oak here. We are adding a timber frame porch/entry area and we are looking at pouring support piers and attaching the posts above ground via hardware since we hit water when digging holes for fencing here. We plan on encasing that in stone pillars up to three feet with a tapered top cap to encourage runoff. Add eaves that are over 18" and guttered and you mitigate the water damage to minimum.
Now, this is just for porch areas...your main structural lumber will create other difficulties for you: Anything you do that creates an opportunity for water to get between two surfaces (pier and post bottom) will be a place for rot to set in. If you build off the ground you would have to shelter the connections from getting direct rain or retaining too much humidity. It is all very complicated, but not impossible.
To encourage longevity in wood exposed to the elements, you are also going to have to coat it with some sort of protection periodically: Raw wood will be dried, warped and damaged by intense sun and rot with time no matter what you do....water finds a way in and always wins.
We live in a VERY hot wet climate....SE Louisiana and our house has Cypress siding (here when we purchased it 3 years ago), so we must seal it; or between the sun and rain will end up replacing it in a couple years. The process is time consuming because I prefer to brush it on since it penetrates the wood better than spraying. Rather than use the nasty epoxy that is recommended we use a semi-transparent stain or you could use thompson's water seal. I'm not sure if theirs any natural way to seal the wood that will last, it may be worth checking into.
Also, no matter what sort of building you decide to undertake....make sure to shoot grade with a transom or builders level prior to beginning if possible. If you can build on higher ground or bring in fill to create higher ground that will aid you as well: Having proper run-off will make sure you don't end up building in the middle of an area that holds water. Even if you are on a hill...it is still worth double checking. If you can't access the transom, just go to the site after substantial rain events and note areas that puddle and hold water...see if you can figure out where the water goes and make sure not to disturb that or build in its path. We know a gentleman who built in an area where no permitting is needed. He put up a very nice home up the hill from a large lake. The only problem is that the first winter after he built, the area experienced torrential rains. Not only did the lake flood up to his front steps, but all the runoff from the hill behind him ran right under his raised home. He ended up doing extensive trenching to stop the river from running under his place. Had he not been on piers, he would have had a disaster.
Just my two cents; I wish you the best of luck with your project and hope you post your progress so we can see how you do!
"Any intelligent fool can make things bigger and more complex... It takes a touch of genius - and a lot of courage to move in the opposite direction." ~Albert Einstein
Joined: Jan 27, 2011
Species is a big factor. I have an old agricultural manual (Doane Agricultural Manual 1946) that used to belong to my great grand father, and it has an interesting table of information, I 'll try and type it in here:
Average life of untreated fence posts
WOOD YEARS TREATMENT recommended (below) Native Juniper 30-40 1 Osage Orange (hedge) 30 1 Black Locust 25 1 Red Cedar 20 2 Arbor Vitae 15-20 3 Catalpa 15-20 2 Burr Oak 15 2 White Oak 11 2 Cherry 10 3 Red Elm 10 3 Honey Locust 8-10 2 Mulberry 8-10 2 Sassafras 8-10 3 Douglass Fir 6-10 4 Green Ash 3-10 4 Red Oak 7 4 Willow 6 4 Pine 4-8 4 (Yellow, Jack, red, lodge pole, ponderosa) Cottonwood 2-6 4 Aspen 2-6 4
treatment #'s 1) does not need treatment 2) treat small round posts- do not treat split or large round posts 3) improved by treatment 4) use only if treated
The rest of the info pertains to different treatment methods: pentachlorophenol , creosote, zinc chloride, and chromatized zinc chloride. I'm happy to type that up if someone wants it, but basically they're all preservatives and I think they're all pretty nasty. I don't know about chromatized zinc chloride or zinc chloride, but creosote is a carcinogen (and I can guarantee thet penta isn't good for you). There's also treating processes, bark stripping techniques, special tools required, drying guidelines, etc.
It also offers this little gem: "If you treat a non-durable wood which takes treatment easily, you will probably have a more serviceable post than if you use a naturally durable wood without treatment"-Illinois Circular 636
Just thought someone might like to see this info. This ag manual has everything in it! From building shelters for livestock from straw, fixing foundations, fences, ag marketing, agronomics, livestock issues, there's even a recommendation for the most efficient temperature for livestock watering systems in winter Sure, you have to avoid the select advice such as: dipping lams with tick problems in a solution of DDT and water.......
This is a smashing line of topic. Some of the last posts are worth hanging on too for sure.
I have been a permie most of my adult life, while masquerading as industrial maintenance staff. In short there is very little that I have not done. Mistakes and triumphs.
This I think that I know for sure. #1 Pine must be sealed above ground, and treated below ground. The better the soil the more this is true.
#2 Treatment is only as good as it's ability to stay in/on the wood. I cover ALL post with asphalt/roofing tar from 8'' above the ground to the bottom, especially the bottom.
#3 Concrete has an average vacancy of 20%. Translation---it will be actively trying to rot your post by leaching. This can be mitigated through several means, not the least of which is by adding volcanic ash, wood ash,steel dust,and others. A higher bag ratio helps a lot also. These particulates should be in the 2 micron class. Sloping the concrete away from the post and good drainage are of course needful as well.
#4 Post should be set on a concrete foundation puck, that is 3-4 inches smaller diameter than the surrounding hole diameter.
#5 Optional. I like copper sulfate,aqua-shade, or ebsom salt, as a topical 5 year treatment (depending on soil type). Two more. I use galvanized nails,(driven into the post and bent), inside the concrete surround. The drier the post end the better, at the time of usage. Add annal details to nauseam here.
The point here is that this is not the place for shortcuts. One mans opinion only ! Do I hear an avalanche ?
2) pole structures are faster, cheaper and sturdier than any other type, so it is worth considering how to get the poles into the ground without issue.
3) if you use black locust, you have nothing to worry about.
4) For structures, shape the surrounding ground to take water away from the strucuture - thus minimizing how wet the pole will get.
5) Build the roof line far enough out to further minimize moisture getting to the pole in the ground.
6) 90% of the problem will be at the soil line. Where soil organisms, moisture and air are the most abundant.
7) My impression is that cement doesn't help.
rubble/rocks can help, but it also seems like in some places it could be an extra expense/hassle.
9) I've always wondered (and never tried): if your pole is gonna be kept dry because of #4 and #5, then what if you mix in a little borax to the fill that goes in around the pole. Borax has a really low toxicity, but is a powerful fungicide. Black locust does so well because it is 4% fungicide by weight. I've run this idea by a few people that are pretty savvy in this space and they think it could be great. We need to get a few people to try and see how things look ten years down the road.
10) charring does help.
11) I've heard some people say that the bag around the poles can be problematic too. Something about how water gets in the bag and then can't get out.
12) I'm still waiting Ben's book and DVD to arrive in the mail.
Borates are excellent but have the problem of leaching away. when subjected to moisture.
Bagging the pole/post end does seem to be bad. It's not IF water gets in there, it is WHEN water gets in there problems occur. Water always wins; see the Grand canyon. Glenn, of Underground cabin fame (infamy?), has had pole bottoms that he had bagged rot out badly. At least one, maybe three.
Tar coated 8 or so inches above ground level down about 12 inches or more will eliminate most of the rotting. As it was mentioned, thia area has O[sub]2[/sub] and water readily available.
I do not like or use concrete around wood poles or posts; only as a poured footer reinforced with steel in an X or a # shape.
Joined: Jan 26, 2011
Not far off with the avalanche comment. Got the big dog weighing in here.
Paul I have some seriously different ideas related to your wafoti thread. Structurally different and hopefully complementary. Would you suggest an outlet for those thoughts ! There is way too much for that thread.
Love the site. Tuned in by way of Jack Spirko. That episode rocked !
Steve Gagnon wrote: Paul I have some seriously different ideas related to your wafoti thread. Structurally different and hopefully complementary. Would you suggest an outlet for those thoughts ! There is way too much for that thread.
We have about a dozen wofati threads now. If you don't see one that is a fit, feel free to start a new one!
Joined: May 04, 2010
paul wheaton wrote: 12) I'm still waiting Ben's book and DVD to arrive in the mail.
Let us know what you think of the DVD. The book is excellent, albeit perhaps a bit light on the design parameters. Inspirational to say the least.
Joined: Jan 27, 2011
Steve Gagnon wrote:
I use galvanized nails
I second that!
I found a more recent study performed by the USDA (published 1999) on the service life of Engelmann spruce, Lodgepole pine, and Rocky Mountain Douglas-fir. They do use chromated copper arsenate to treat them though....
There's a mix called "boat soup". It's very good for wooden boats, applied regularly. It's similar to what tbug was talking about (I think), but has one more thing: Pine Tar. Pine Tar is a more or less natural product, which is used mostly by farriers these days. Some years ago a baseball player got in trouble for having too much of it on his bat when he used it to make the handle easier to grip.
Mix a quart of turpentine, a quart of linseed oil, a pound of wax, and a pint of pine tar. Heat (Outside! Carefully!) until the wax melts. It will cool to a paste that can be rubbed on tool handles, etc.
Seems expensive for lots of posts though.
My tractor shed is a lean-to on the back of my barn. The support posts on the outer side are hackmatack, a.k.a. tamarack, a.k.a. larch. StewartrIL posted a fine list of rot resistance, and hack isn't on it, but it is a good rot resistant wood. The posts sit on round concrete footings. Each footing has a small piece of rebar sticking out of it, up into the post. There's a small piece of asphalt shingle between the concrete and wood to prevent moisture rising. There's also a fair overhang, which reduces, but doesn't eliminate, the rain spray on the posts.
Mark Vander Meer
Joined: Dec 12, 2009
That's the way to do it - cement piers with a moisture blocker. Larch makes a great rot resistant post, but only if you use the butt log, and the heart wood.
I still see no advantage to putting a post in a hole in the ground.
This guy uses charring on the outside of buildings, reminds me of a tar kind of treatment I've read on these forums that's common in scandanavia or switzerland I think. This would be interesting to experiment with, and certainly could help for some solar gain with all that exposed charred wood.
I assume that the stone pliths wont leach moisture into the logs like concrete does, being much more dense. I've seen in old traditional Japanese buildings the act of carving/fitting the bottom of the pole to the stone for a solid fit, I wonder how time consuming that is, hahaaaaaa.
Devotion is the intensity of love. Surrender is the fulfillment of love.
One angle to look at the question regarding poles in the ground is to ask yourself this question: How many old houses do you know that have this construction. This will give you the answer how long the poles in the ground will last.
I would not recommend underground poles for anything that is supposed to last more than 10 years. Wooden fences are made this way and is the end of the pole is charred, the wood cut in the right time of the year there is a chance they last 10-20 years and are then replaced.
For houses, even if you are building on a solid rock you should use stones if you want the base of the house to last.
If the ground is something else than rock, it should be dug about one meter deep (this is an estimate and completely depends on the situation) and filled with sand and a large rock put on top. You only have to use rocks in the corners, or every six meters (this is how long logs you should use on top of the rocks).
You can see that the house is resting on rocks that are dug underground and logs on top of them.
On the bottom of this page is and image of a house that has regular stones and log on top. (The page is in finnish) If you click on the links to the left there are some other example images of different houses.
Here is another one. The stones are just laid on top of each other:
Joined: Aug 10, 2011
Location: Southern Oregon
I'm surprised it wasn't mentioned here, or maybe it is elsewhere, but what about wrapping the lower section in thin sheet metal? It seems to me that a metal wrapped pole, with the metal extending up at least a foot or 2 out of the soil, with a circular "puck" footing of concrete, and the hole packed with rubble, would last quite awhile.
I also find it surprising that the structural advantage of a sunken pole versus a piered pole is not so abundantly clear. Compare 2 shovels, one that you stomp on and sink the spade, the other is resting on the soil. Less need for lateral and diagonal bracing.
Clearly there are many factors involved in pole life expectancy. Where I grew up here in Arkansas, (a property my mom still owns but doesn't live at) there is a pole hay barn built by my grandpa in the mid to late 1950's. We get some pretty serious weather here from tornadoes, high winds, flash flood thunderstorms, and rarely 1- 2 feet of snow. That pole barn has stood up to all of these conditions for 50 - 55 years or so. I haven't been out there in a couple years and I didn't have quite the same building/construction enthusiasm as I do now but I do remember the basic structure. It's a decent size barn, maybe 35 x 30 or so. It originally had a tin roof and siding but it was replaced 7 or 8 years ago with the the regular corrugated steel panels. It has a dirt floor but my mom put gravel over part of it a several years ago.
The poles are what people here call cedar or red cedar, though it is actually a species of juniper. It's very common locally and was used in many of the old farm structures. I have no idea if they were treated by my grandpa but those poles have been in the ground for 50 - 55 years with the bark still on them and showed no signs of rotting whatsoever a couple years ago when I was there. There is a 2 x 8 or 2 x 10 treated drip board all around the base and the eves are around 2 feet if I remember correctly. I believe it's very slightly higher than the surrounding ground.
I have never dug up a post but I'm pretty sure it's just stuck in the ground with no gravel or anything whatsoever around it. The poles have probably never been subjected to direct splashing from water but the ground does get very saturated around here certain times of the year.
Those red cedar / juniper posts seem to be pretty awesome in the right conditions. I am using a lot of them from the property I purchased in 2012 and plan on using them in my hybrid pole / psp / earthbag structure. As Paul mentioned, it's all about diverting the water around your structure so that it wants to go somewhere other than towards your posts.
I build all my buildings off the ground. I scrape away the topsoil and tamp the subsoil and then lay broken concrete slabs down. The trick is to tamp the earth to force the settling to occur before you build. Stays nice and level that way, and for drainage issues, dig a little deeper and put a layer of tamped gravel down first. And charring is excellent for fence posts, which are easily replaced. But a building should always last a lifetime. But for a pole building that needs to be built quickly and on a limited budget stick them in the ground. It is so easy to jack up a post, cut off a rotten butt and pour a concrete sonatube underneath it later on, one at a time as they rot and become jeopardized. For fenceposts I use 4x4 of oak that I cut on my sawmill. The heart wood is not as tasty for the fungi in the soil. If all you have is a chainsaw, square up the butt end of pine poles to remove the sapwood and that will add years to their life. just my 2 cents worth. I'm only 28 and have only had my land for 3 years so I am by no means an expert. But in my area in michigan there are many old barns and houses to explore and study built in many styles by pioneers from many different cultures over a 100 years ago that are still standing. And the amish in the area use the techniques still to this day, as do I. I was lucky enough to have a crumbling foundation already on my land when I bought it, which I repaired and built our house on, before the building inspector had a chance to tell me no.
Joined: Jan 20, 2013
to peter dejay: the metal wrap is an excellent idea. The zinc in the tin is anti-fungal. I noticed that on some of the old barns with wood shingles there is a strip of galvanized tin at the top, so that when it rains the zinc is washed down over the wood shingles.
Joined: Apr 12, 2012
I noticed a dilapidated house that is completely falling apart down the road the other day. No telling how old it is but the front porch has red cedar posts that still look fine. The porch is intact and level and those posts are standing tall without issue. Red cedar/juniper really is some extremely rot resistant stuff.
Joined: Jan 17, 2011
this is only my opinion:
DO NOT PUT PINE POLES IN THE GROUND!
because they will rot. If you want to have your building last beyond half your lifetime, spend the extra time and effort to install a masonry pier or foundation. A stitch in time saves nine. If you cant find time to do it right the first time, when will you find time to do it again? Pine is notorious for rotting, even above ground, if you choose to use it, make sure it it sound and dry before you use it and make appropriate steps to keep it that way. Don't gamble on other peoples advice on thier good experiences. Putting pine in the ground, treated, bagged or whatever is a bad idea. Use masonry, let history be your guide.