Considerations for sealing wood beams for ground contact

Impregnating with creosote is the typical solution - used for railroad ties and telephone poles.

Simple barrier materials will be breached and then retain moisture. Use good drainage if possible.

Check the US Forest Product Laboratory for information; they support "Durability and Wood Protection Research"

I hear you on barrier failures. If I apply glass, there is really no way to practically test for leakage before installation.

I do not believe Creosote is available for all parties? IE highly toxic and likely to leach, possibly into water? I guess I am trying to use something that is safe but I assume safe also means safe for critters too... I have no remorse for wood eating critters.....Terminites be my biggest frustration.

I know Borates are common treatments but I want a 100yr plan in place whether that is with injection tubing by the wood or what not.

What's the exact application? Could you substitute concrete or a polymer material? How about using redwood?

This is basically a pole barn. Need to have the beams secured into the ground for structure so pouring a footing or pier loses the continuity in lumber grain. However, I was sort of thinking of something synthetic and tying it together above ground but I remember all the synthetic lumber products having very poor structural specs.


I guess I am open to ideas. Still trying to toss the idea of concrete around all the poles. great for firm connection and stiffness but possibly will retain water?

All in all, every effort will be made to drain water away from these areas which I think is a prime reason of failure in most of these types.

What about concrete poles?



Mike Halloran
Pembroke Pines, FL, USA

Not even remotely familiar with something like that. I have to consider attaching a lot of lumber to them though which could present challenges.

Are you thinking of pour in place or precast?

I am presuming you have looked at preservatives like: chromated copper arsenate (CCA). Wood treated with CCA is one of the most common types of preservative-treated lumber available today. It is toxic to termites and to fungi that like to eat wood.
If you have livestock that like to chew on wood, a common method of preventing contact is a sheet metal collar around the treated base.
Also, if this is inside, the barn, your floor should be dry, unless you have run through from a higher elevation.
B.E.

You are judged not by what you know, but by what you can do.

You mean like this Mike?


B.E.

You are judged not by what you know, but by what you can do.

Yes, I don't think there is much question that CCA will work "for a while" and probably quite long for termite protection deep inside. However, the surface will lose concentration and rot will eventually set in if they get wet a lot. I am trying to figure out a way to ensure 100yr performance here.

Regarding concrete poles, I would be looking for dimensional products so lumber can attach easily. I do like the idea. many have said just to build an Ibeam building but the interior build out is much more difficult and alterations later are a problem. Already had issues with tension cables in the way. Wood is just more modular. Just need to ensure my connection to the ground is well designed.

A search on [precast concrete poles] found a lot of lighting and utility pole manufacturers, and these guys:




Mike Halloran
Pembroke Pines, FL, USA

You want to ensure 100yr performance of a wood product with an air-moisture interface in soil or concrete? Keep dreamin'.

Utility poles, even the ones preserved with creosote, had a maximum life of less than 50 years on average. Many were replaced in the 20 to 30 year range. Those were well treated, partly because of the critical nature of their service.

A barrier system won't work as others have noted. For design, consider pole embedment and forget the concrete. If you want a concrete slab, isolate the slab from the poles with a coating of asphalt mastic.

I remember touring some medieval castle in Germany.

They said the wooden columns were soaked in ox blood.

For what it is worth , I was born and raised in a 400 year old wood framed house, with brick panels or wattle and daub fill ins between the framing. The old builders in that house did not allow the timbers to go below grade. They all rested on clay tiles at ground level.
The timbers were mostly oak, the main frames were about 12 to 14 inches square.
In the 19 60s we discovered that the house had suffered a major beetle attack and had to treat the whole house with Cuprinol wood preservative.
B.E.

You are judged not by what you know, but by what you can do.

IT sure looks like Mike and Berkshire have the right idea by avoiding wood/soil contact for obvious reasons. Mike, I really appreciate the link on the concrete columns. I will admit that I am a bit nervous with that system being as stiff and strong as continuous lumber but it fixes two issues I have concerns with. One is the rot, the other is replacement in the event of disaster (tornado alley here).

My brother had done extensive work with polymer modified concrete which might really come in handy here. I was thinking of a custom formed in-ground pier with a dimensional top to attach a custom steel beam mount similar to what was linked. However, it would seem mounting at low as feasible and maybe making the dimensional part a bit wider would better ensure there are no failures there.

Do you guys have any expanded thoughts or ideas on this method of build? I will have to look closer at loads to see how much bending is really on that beam. I seem to remember that uplift is a primary concern but can be easily mitigated with uplift lugs of about any type.

Ron, I did not understand what you meant with "pole embedment but forget the concrete". It sure seems concrete would be the only answer in the ground for lifetime performance? Or stone I guess.

All in all, I would need to devise a slick build style that would be both fast and economical. I have a full machine shop so planned to make the steel connections and such.

Thanks again guys!!! Always get some great ideas here.

Fast line...you don't necessarily need concrete. You can achieve lateral fixity of the poles by appropriate embedment. Many pole barns have no floor other than bare ground. The poles are not usually encased in concrete, just embedded sufficiently to resist lateral loading.

Ron, I do agree and have had conflicting thoughts regarding concreting any beams in the ground. Natural contraction of the lumber could cause them to be loose. I had originally intended to concrete and reenforce a floor for each pole, then bed embed with a mixture of gravel and sand for high compaction upon placement. This would also work to drain water but would also easily act as a well for water too.

What are you thinking for a long life pole system? I really like the idea of concrete but setting the lumber in top would seem to build some really high concentrations right at the connection.

Interesting question. I built a pole barn about 17 years ago - 36' X 48', 2 story. I set pressure treated poles directly into the soil about 3 feet deep with a bag of dry concrete mix poured around each before back filling. We get great lakes winters of many freeze/thaws. The soil is mostly heavy clay. So far the poles have held up and the barn is as square and plumb as the day I finished it. But I'm now thinking in the next year or 2 to dig around each and pour a concrete footer for each to give it another 50 + years. Also, the floor is about 6 inches of gravel but I may have a concrete slab poured. It used to house horses and other animals but has been empty for awhile other than some equipment. In retrospect I would have done the concrete at the initial build and set the poles on the concrete.

Have Fun!

James A. Pike

"Natural contraction of the lumber could cause them to be loose."

Any embedded posts or 2X lumber I've been around have been TIGHT. A few times folks greased up some slightly tapered 2X for removeable formwork and they could not even be chiseled out. Maybe after 15 or 20 years its a different story.