Treating lumber--what do you think about.....

[azmtnman]

    I am in design stages for building a pole building for a house. I want to use my own lumber (6x6 posts). I looked online a found a recipe for home-treating lumber with borax and boric acid. Anyone ever use this?
   My main frame posts will be "dry" as it will have a 8' covered porch on all four sides and concrete floor. Would they even need to be treated? (I'm guessing yes--for bug prevention) My climate is fairly dry but we have a rainy season.

[Kbeitz]

My recipe is 50/50 diesel fuel and roofing tar. Works great for me. This building was built 35 years ago with soft pine. No rot anywhere on it yet.

[Deere80]

I do the same thing as Kbeitz but use 25% diesel 75% roofing tar and heat it up in a metal bucket to mix it together then paint it on the post.  here is a hunting shack I built with 8x8 posts.

 

[Georgia088]

Interesting.  This "tar/diesel" paint you apply works well enough to set the posts in the ground? Or, are you only using for above ground applications?

[nybhh]

I'm very interested in this too.  

I'm milling lumber for a bridge across our creek out of EWP that I'd like to last a while.  I'm pouring a concrete pad on each side of the creek for the 10"x10" timbers to sit on to keep them off the ground and decking the bridge in 2x8s.  Was also thinking about using Rustoleum Creocoat but could see using the tar/diesel mixture on the timbers and the creocoat on the decking.  Does anyone know how this creocoat holds up compared to a regular oil or water based stain?  

Sorry to hijack  :-[

[Deere80]

I use it for under ground, the posts are cedar.  You could use it for above ground but you rub against it you will be full of tar.  I did the same thing on a 48'x40' pole barn.

 

[Kbeitz]

My gazebo sets 1/2 in water. With the 50/50 mix after a couple weeks nothing rubs off nothing. It's the same mix I used in my solar kiln.

[azmtnman]

Was also thinking about using Rustoleum Creocoat but could see using the tar/diesel mixture on the timbers and the creocoat on the decking.  Does anyone know how this creocoat holds up compared to a regular oil or water based stain?  

Sorry to hijack  :-[

I'd be interested to know about the Rustoleum product too.

[YellowHammer]

Kbeitz, nice place on the water.  

[azmtnman]

I use it for under ground, the posts are cedar.  You could use it for above ground but you rub against it you will be full of tar.  I did the same thing on a 48'x40' pole barn.

Nice building!
I see you are in ND. Are those trusses on 8' centers? What's the snow load on those?

[loganworks2]

If you are going with a cement floor in the house you could pour a monolithic grade beam slab. Then you do not need to have any wood in contact with earth. 

[azmtnman]

If you are going with a cement floor in the house you could pour a monolithic grade beam slab. Then you do not need to have any wood in contact with earth.

Had to Google that!
We call that a "foundation" here.
I'm going with post frame, or pole building, for quick, inexpensive and versatile construction.
I was hoping someone would weigh in on whether or not my idea of the posts being 8' inside the roof would keep posts moisture free.

[starmac]

I would sure think they would stay pretty dry, especially in your area.

[reswire]

There is a site called Poles Inc., that sells copper napathate for $200 for four gallons of concentrate.  If you mix it at 2% (strongest sold in stores now is 1%), with diesel fuel, you can get 20 gallons total.  My dad used it 25 years ago on untreated 2x4's, and they are still solid.  He laid them down for a walkway in the swampiest part of his land.  I'm impressed every time I look at them.  I've used this for fence posts on my farm, and 5 years later, no problems  (I coated poplar 4x4's).  I've been told that it works best on green lumber: the green wood will allow the mix to penetrate where dried wood will not.

[Don P]

But I wouldn't bet the farmhouse on these methods.
The footings under the columns and the columns themselves are your foundation.
Borates do leach into a "sink" like the earth if and when the wood gets above about 25% mc.

Nail laminated columns are another way, using treated below the splices and untreated above.
http://products.midwestpermacolumn.com/Asset/Nail-Laminated-Column-Design-ANSI-ASAE-EP559.pdf

Dr Bonhoff is pretty much the guru of that way of making post frame columns, many papers online by him.
http://www.constructionmagnet.com/frame-building-news/what-every-post-frame-builder-should-know-about-laminated-columns

Permacolumn makes a concrete post bottom and wet set anchors as well

This is the powerpoint Dr Manbeck uses in an introduction to post frame buildings, some good info;
http://www.woodworks.org/wp-content/uploads/C-WSF-2012-Manbeck-PF-TX-VA.pdf

[Gary Davis]

I have a deck used borate salts on it then coated it with coper naphthenate  (the borate will leach out if in contact with water)   the copper goes on an ugly green but after a month turns a golden brown ,I my built my deck in 03 still looks almost like new

[nybhh]

There is a site called Poles Inc., that sells copper napathate for $200 for four gallons of concentrate.  If you mix it at 2% (strongest sold in stores now is 1%), with diesel fuel, you can get 20 gallons total.

This is a great resource.  I just looked up the technical data on the creocoat (here) and it uses the same copper naphthenate plus some other chemical which I assume is what makes it black. That is $40 per gallon vs about $12.50 (including disel) for yours.  Mixing in a little roof tar might give it a more pleasant color than the green.  I have a gallon of this that I always used on the cut ends of PT lumber.  I just looked it up and it is 10% copper naphthenate (by volume) at $28 per gallon so that isn't too bad either but it is an awful green color as well. Looks like the concentrate that poles inc sells is 68% by volume. This is really great info everyone!  Thanks for sharing.

[azmtnman]

Great info, guys! 
I'm learning a lot!

[Larry]

Having worked as an outside plant design engineer for a telephone company I learned a lot about treating poles. Bell Labs spent years testing every combination of pressure treatment known. I learned its not an exact science with a lot of variables, some we don't understand. I've seen in service 100 year old poles just as sound as the day they were planted. Also seen poles a couple blocks away with rotted butts after 30 years. Same species and treatment. The design life of poles is 50 years meaning they are expected to last that long before failure.

A couple of things I learned. Pressure treating normally only penetrates a couple of inches. All poles crack leaving untreated heartwood exposed. Rot normally starts in the center of a pole. Most of the strength of a pole is in the outside shell.

For outbuilding construction, I'm sold on nail laminated posts. Since the treated part in the ground is 1-1/2" thick, complete penetration of the treatment is assured. Don provided a couple of links to well designed laminated posts.

[starmac]

Question for the op, are you running your poles through the concrete slab into the dirt under it?  I would think even though your poles are back 8 feet from the overhang, they will still wick moisture from the ground.

[azmtnman]

Question for the op, are you running your poles through the concrete slab into the dirt under it?  I would think even though your poles are back 8 feet from the overhang, they will still wick moisture from the ground.

Yes. I was hoping the 8' covered perimeter would limit moisture contact. There isn't much moisture to wick from the dirt I wouldn't think. We get 3-4' of snow (winter average) and some short downpours in the summer.
Soil is well drained and humidity is low most of the year. I wonder if those posts would ever see moisture after the floor is poured and the roof is on??

[starmac]

I guess I don't understand why you want the post under the concrete, I would prefer no ground contact with them myself. I guess it is possible they last forever, but what a wreck if they don't.

[nybhh]

I agree.  If you are pouring a slab, set some lag bolts into the wet concrete at your post spacing and come back with these.  That is a 4x4 but they make a  6x6 also.  Makes it a breeze to replace post if you ever need to.  We did this on our deck and one of the PT post warped real bad when drying out so we came back and replaced it later, was a breeze.

[Kbeitz]

Not treated and touching the ground... Will get termites ...

[azmtnman]

I agree.  If you are pouring a slab, set some lag bolts into the wet concrete at your post spacing and come back with these.  That is a 4x4 but they make a  6x6 also.  Makes it a breeze to replace post if you ever need to.  We did this on our deck and one of the PT post warped real bad when drying out so we came back and replaced it later, was a breeze.

You'd have to pour a foundation under those. 
In a post frame/pole building, the underground part of the post is your foundation.

[azmtnman]

I guess I don't understand why you want the post under the concrete, I would prefer no ground contact with them myself. I guess it is possible they last forever, but what a wreck if they don't.

You are correct!
Concrete around them or not, they would be a bear to replace.
Post frame construction has been around for decades. I have seen some pressure treated rot off at the ground and some still good after 40 years while the old creosote posts are still good--some because of different methods of construction, location, etc. I see that old cabins back east last forever with a good roof with lots of overhang. That is my thought process here. I asked the question here to glean from the WEALTH of knowledge and time-tested experience (like Larry and KBeitz)
I will have a tight construction budget but I want to do it right as possible with wood--which isn't always a new method with some manufactured product without time-tested success. I can harvest logs, mill them and my cost on a 6x6x16 is about $3.00. That leaves me $$$ to buy other things I don't have the time or equipment to make efficiently.

Just explaining my thought process.

[azmtnman]

Right now, based on what you guys have told me, I am going to coat the bottom with copper napt----whatever and then seal with diesel fuel and roof tar. I want to make sure they are treated up about a foot above ground.
Am I on a right track here?

[DPatton]

Azmtnman,

You live in Arizona and your building codes are likely quite different than the building codes where the rest of us responding to your post are from. The majority of us live in parts of the country where concrete footings / foundations are a fact of life and nearly unavoidable. I live in an farm and agricultural area and these pole barn type metal building homes are becoming more and more popular but they are being constructed with a cast in place type perimeter foundations to protect from freeze thaw and ground movement. Are you in an area where building codes apply or will determine your foundation requirements? Or do your codes allow for wood post embedded in the soil with a floating slab on grade in residential construction?

[azmtnman]

Azmtnman,

You live in Arizona and your building codes are likely quite different than the building codes where the rest of us responding to your post are from. The majority of us live in parts of the country where concrete footings / foundations are a fact of life and nearly unavoidable. I live in an farm and agricultural area and these pole barn type metal building homes are becoming more and more popular but they are being constructed with a cast in place type perimeter foundations to protect from freeze thaw and ground movement. Are you in an area where building codes apply or will determine your foundation requirements? Or do your codes allow for wood post embedded in the soil with a floating slab on grade in residential construction?

I don't imagine building codes will be an issue. (Don't get me started on building codes!)
Even though we have 4 seasons at this elevation (6500 ft), I doubt the true frost line is over a foot in a cold year. It either snows on top of unfrozen ground or the sun melts the ground during the day even if air temp never gets above freezing.
My posts will be buried 3'--freeze/thaw won't be an issue. 
I'm just looking for the best possible way to preserve the underground part of the posts and that just above the ground.

[Don P]

I don't know of any prohibition to post frame residential construction in the building codes. They do require treated but the basic concept is ok, not much different than a permanent wood basement as far as burying wood. It works fine if done correctly.

I'm sure the op knows all this but for general info, one of the main reasons for burying the post is to pick up lateral bracing from the soil. Earthfast construction was well known to native Americans, Anglo-Saxons and just about every other culture. Without good ways of treating the wood those buildings didn't last long. In the UK the Norman invasion brought with it masonry foundations and a number of those buildings survive.

When you go to a post on top of a pier or slab that lateral bracing needs to come from something else. In a fully enclosed barn or house the wall sheathing provides far more bracing than the soil would so that isn't an issue. There is an engineered untreated pine pavilion not far from here in the state forest. They poured piers to future slab level first and attached the posts to those concrete piers. When the building was complete they poured the slab. Steel post frame buildings are done that way also.

In an area with no inspector, a 1' frost depth, and no real moisture getting to the slab edge I'd take the digging, treating, and post money, do a thickened edge slab and build on top of it, you need moisture to heave. There's plenty of ways to do it though.

[starmac]

I will be very surprised if you don't have building codes there, you are talking about a state that requires a license to do anything at all, heck probably to use the restroom. It has got to be the only state that a sheriff would have the nerve to come 3 miles inside the gate of a ranch and give you a ticket for your dog not being on a leash, and yes I witnessed that one.

That said I have seen old buildings in New Mexico built with wood beams laying on the ground, yes they were going bad, but who ever built them had long been dust too. The climate was a little drier than the showlow area, but not by a whole lot.

Just a thought , if you are going to pour a slab anyway, just trying to keep from the expense of a footer, but a guy might drill a whole say 3 foot deep and pour a 12 pier under the slab every where a pole would be. Just an idea, there may be a reason that would not fly.

I know in the prescott area we could not even use the same dirt we dug out to back fill footers with, according to the code officials, so good luck.

[starmac]

It is kind of funny, but I had a guy here day before yesterday, trying to buy my log truck, he wanted it to haul logs from williams to south of Holbrook, either snowflake or showlow, I forget which he told me. Do they have a mill running at Showlow now.

[nybhh]

It's a good point that the climate is much dryer there so this all may be mute but if you do bury the poles, backfilling your hole with crushed gravel instead of soil will keep any moisture in the ground away from the poles and the crushed gravel locks into place well enough to provide the lateral support you are looking for.

[Don P]

Just to clear up on building codes, 49 states use the IRC. AZ uses the 2012 version but adopts locally so it depends on that county. Enforcement is always local throughout the country, that is what varies so much. When you see people say "we have no codes here" usually what that really means is they have no enforcement there.

Generally speaking most codes don't vary all that much on the basic structural stuff. If you answer a question basing that answer on an actual code cite, not from what you think or have heard but from actually referencing the model code, you are probably going to be right in there. In other words the code is more uniform than many people think. As an example the methods of building a foundation are relatively uniform, as you get into high seismic or wind areas some of the weaker methods are prohibited. I can build a rubble stone foundation, California cannot. Frost depth and snow loads vary so those are adjusted with local data. I put a footing 2' below grade, Texas need only be 1' deep.

Post frame is not prohibited for residential construction but is not prescriptive. It falls under engineered construction. I have code and enforcement so if I wanted to use that method here on a house I would need a sealed set of plans from an engineer that knows how to design the structure.  For instance if he is picking up lateral restraint from the soil he is probably not too worried about frost depth, he'll likely be calling for 5-7 feet of post embedment. As I noted above, in a fully enclosed building lateral restraint can be better handled by sheathing so we don't need the post embedment for that. The soil moisture that can cause rot is much lower than what can cause frost heave. Underneath a house I can put in shallow footings without fear of heave yet if I have poorly or untreated wood in ground contact I'm inviting rot and insect problems. 8' under the eaves I'd risk heave before I'd risk rot. In a situation where racking is better handled by braced walls, the frost depth is shallow, and actual treated posts are unavailable what is the advantage of that method of construction?

[azmtnman]

It is kind of funny, but I had a guy here day before yesterday, trying to buy my log truck, he wanted it to haul logs from williams to south of Holbrook, either snowflake or showlow, I forget which he told me. Do they have a mill running at Showlow now.

There is a mill in Snowflake/Taylor. I guess they put the hurts on the tribal sawmill. We also have the Forest Energy pellet plant in Show Low.
I'm looking for property over around Vernon which is in Apache County.

[azmtnman]

I will be very surprised if you don't have building codes there, you are talking about a state that requires a license to do anything at all, heck probably to use the restroom. 

I know in the prescott area we could not even use the same dirt we dug out to back fill footers with, according to the code officials, so good luck.

Really? I have found AZ to be much more of a free state. It has it's overbearing qwerks, but in general much more free than most.
I'm not opposed to building codes for good structural practices. But building codes have brought us things like mold. If I own a piece of property, I should be able to build a structure for a house the way I want to. I'm originally from a place where your house had to be a minimum square footage and couldn't be built out of native logs. Whose business is that? If you borrow money, that's between you and your bank. If you don't want somebody building something you don't like next to you, live in a subdivision with an HOA with terms you like.

[Don P]

This is why it is good to read the laws and understand them. Building codes do not regulate the minimum size of a house nor do they prohibit log construction. Local zoning laws or covenants on the land do that. I can petition my neighbors and local government much more easily and successfully than the state.

I built before, during and after the mold era and yet have never to my knowledge had a house with a mold problem. Was it the building code or was it some builders practices that caused that problem?

In 2007 the building code folks published an amendment to the prescriptive codes for log homes, the log home standard. It took a number of years to bring that about. This moved typical log construction from "engineered" to "prescriptive". We can build many kinds of log home now without needing an engineers seal. When we do something repeatedly the same way and prove it works then we can move it from engineered to prescriptive.  During the development process of the log home standard as with any proposed changes there is a public comment period, I participated in that. A number of people and inspectors would like to see the post frame and timberframe folks do this.

I helped a gentleman online who was building his house on his property. He made many mistakes and failed to correct them, ignoring things he didn't want to hear. It was his property and his risk. Stupid hidden mistakes like failing to nail down the rafters and failing to put footings under posts. Then he sold the house and started again. Do we need to rethink what it is "mine" to do with as I please?

There was a deck collapse in GA over the weekend, a number of people were on the deck, two were under it. The media will say it was overloaded, it wasn't, the connections to the building will be found to be lacking. Someone thought their work was good enough and others paid the price for that ignorance. This will be repeated almost every weekend until snow flies again. Should we learn from the mistakes of others? There was an amendment to the code around the '08 edition with a prescriptive attachment detail and there is a deck construction standard of best practices making its way through. The inspector reminds me when I complain, many of these codes are written in blood, go carefully .

[Deere80]

I use it for under ground, the posts are cedar.  You could use it for above ground but you rub against it you will be full of tar.  I did the same thing on a 48'x40' pole barn.

Nice building!
I see you are in ND. Are those trusses on 8' centers? What's the snow load on those?

Yes they are on 8' centers but can't remember what the snow load is on them.  Knock on wood I have not had a building fall in yet but it is snowing right now heavy wet snow so hope I didn't jinks myself.

[Don P]

I was up early this morning watching the snow, figuring out what to do today, having a cup of coffee and reading the latest copy of Rural Builder that had come a few days ago. There was a particularly timely article about moving to make residential post frame buildings prescriptive construction. I wrote the editor and asked for permission to repost it here. Sharon wrote back asking to use my note in next months letters to the editor. She sent a pdf copy of the article which is below and also posted it on their website. I agree wholeheartedly.

http://www.constructionmagnet.com/news/locked-residential-make-case-prescriptive-post-frame-building-code

She also sent word that next month we will hear from the opponents.